Guidance on the WHMIS supplier requirements

Introduction

WHMIS overview

The Workplace Hazardous Materials Information System (WHMIS) is a national information system designed to protect Canadian workers by providing safety and health information about hazardous workplace materials. The key elements of the system are hazard classification, hazard communication through cautionary labelling of containers and the provision of safety data sheets (SDSs), and worker education and training programs.

WHMIS is implemented through coordinated federal, provincial, and territorial (FPT) legislation. Federal legislation related to WHMIS supplier requirements consists of the:

• Hazardous Products Act (HPA)
• Hazardous Products Regulations (HPR)
• Hazardous Materials Information Review Act (HMIRA)
• Hazardous Materials Information Review Regulations (HMIRR)

The purpose of this guidance is to provide guidance on the requirements of the HPA and the HPR to suppliers of hazardous products destined for Canadian workplaces. A supplier is defined in the HPA as "…a person who, in the course of business, sells or imports a hazardous product." This guidance also provides suppliers with information on the HMIRA and its regulations and the mechanism to protect confidential business information (CBI) while still disclosing critical hazard information to workers.

The HPA provides Health Canada with the authority to regulate the sale and importation of hazardous products intended for use, handling or storage in Canadian workplaces. The HPR sets out the hazard classification and hazard communication requirements. The HMIRA and its associated regulations allow CBI to be protected and set out the process for filing a claim for exemption. Additional information on the HMIRA and CBI can be found in Appendix A of this guidance.

The Workplace Hazardous Materials Bureau (WHMB) in Health Canada administers the HPA and HMIRA. Health Canada's responsibilities under WHMIS are to:

• Administer and provide guidance to suppliers on the requirements of the HPA, HMIRA and their associated regulations
• Collaborate with FPT occupational health and safety (OHS) agencies on WHMIS implementation
• Represent Canada in international meetings, such as meetings of the United Nations Sub-Committee of Experts on the Globally Harmonized System of Classification and Labelling of Chemicals (UNSCEGHS)
• Collaborate with the United States Occupational Safety and Health Administration (U.S. OSHA) on the development and implementation of hazard classification and hazard communication requirements

The employer and worker requirements of WHMIS are not the focus of this guidance. Each of the provincial, territorial, and federal agencies responsible for occupational health and safety has established employer WHMIS requirements within their respective jurisdictions. The Labour Program at Employment and Social Development Canada is responsible for workplaces under federal jurisdiction. For further information on employer WHMIS requirements, contact the occupational health and safety agency in your jurisdiction. Specific WHMIS requirements for any jurisdiction can also be found at WHMIS.org. This site is Canada's portal to WHMIS information for all WHMIS stakeholders, including suppliers, employers, workers and trainers.

Further information

Note: In case of discrepancy between this guidance and the acts or regulations, the official versions of the acts or regulations will prevail.

This guidance contains references to legislation and guidance pertaining to other Competent Authorities, for example, U.S. OSHA's Hazard Communication Standard (HCS). These references are often made for comparative purposes and, in that context, are based on Health Canada's understanding of the legislation and guidance. For compliance purposes and additional information regarding the legislation and guidance from other Competent Authorities referred to in this guidance, readers should consult the relevant Competent Authority.

Specific questions or comments regarding this guidance, including questions about WHMIS and the implementation of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) for workplace hazardous products in Canada can be directed to Health Canada: whmis-simdut@hc-sc.gc.ca

Additional information can be found on Health Canada's WHMIS website.

Structure of the Guidance on the WHMIS supplier requirements

This guidance includes the following sections:

• Introduction
• Hazardous Products Act
  Outlines the statutory requirements for suppliers under the HPA
• Hazardous Products Regulations
  Provides comprehensive information concerning the supplier requirements under the HPR. This section of the guidance is divided into 8 distinct parts, which are identical to the Parts of the HPR:
• Part 1 - Interpretation
• Part 2 – Classification of a product, mixture, material or substance
• Part 3 - Labelling
• Part 4 – Safety data sheet
• Part 4 includes 3 annexes:
• Annex 1 – Information elements on safety data sheet – Schedule 1 of the HPR
• Annex 2 – Information elements on safety data sheet – Biohazardous infectious materials, Schedule 2 of the HPR
• Annex 3 – Comparison of ingredient concentration disclosure and confidential business information protection requirements under WHMIS and the U.S. Hazard Communication Standard (HCS)
• Part 5 – Exceptions
• Part 6 - Additional requirements
• Part 7 - Physical hazard classes (includes chapters for each of the physical hazard classes in the HPR)
• Part 8 - Health hazard classes (includes chapters for each of the health hazard classes in the HPR)
• Appendix A: Hazardous Materials Information Review Act: Mechanism to protect confidential business information
  Provides comprehensive information on the claim for exemption process, which protects certain information from disclosure, pursuant to the HMIRA and the HMIRR.
• Appendix B: Developing a generic chemical name
  Provides guidance on developing a generic chemical name.
• Generally, the structure of the guidance includes each statutory or regulatory requirement followed by a discussion of the particular requirement, including examples where appropriate.

GHS implementation in Canada and WHMIS

WHMIS came into effect on October 31, 1988 through coordinated federal, provincial and territorial legislation. On February 11, 2015, the Government of Canada published the HPR, which, in addition to the amendments made to the HPA, modified WHMIS to incorporate the GHS. The Controlled Products Regulations, the predecessor to the HPR, and the Ingredient Disclosure List were repealed. With the incorporation of the GHS, the hazard classification and communication requirements of WHMIS are aligned with the workplace hazard classification and communication requirements of the U.S. and other Canadian trading partners. It is possible to meet both Canadian and U.S. hazard communication requirements for a hazardous product using a single label and SDS. Suppliers selling or importing hazardous products intended for use, handling or storage in Canadian workplaces are subject to Canada's legal and health and safety frameworks, including official languages requirements.

As an integrated hazard communication system, the key objectives of implementing the GHS in Canada are to:

• increase worker protections through the adoption of a globally recognized standard for communicating the hazards associated with workplace hazardous products
• facilitate trade through common labelling and other hazard communication requirements
• minimize costs for businesses and consumers by limiting the need for retesting and reclassifying workplace hazardous products from, or for, different markets

The GHS covers all hazardous substances and mixtures and applies to all potential exposures to all hazardous chemicals in all types of situations, including production, storage, transport, workplace use, consumer use and in the environment. The GHS (commonly referred to as "The Purple Book") standardizes the criteria for classifying chemicals according to their health, environmental and physical hazards, and standardizes the hazard communication requirements for labelling and SDSs. The GHS document is updated and a revised version is published every 2 years, following decisions taken by the UNSCEGHS. Initially, the HPR was based on the building blocks of the fifth revised edition of the GHS. Following amendments published on January 4, 2023, the HPR is now based on the building blocks of the seventh revised edition of the GHS, with the exception of the new Chemicals Under Pressure physical hazard class which was adopted from the eighth revised edition of the GHS.

The GHS includes 3 groups of hazards:

• Physical hazards (which represent hazards relating to physical and chemical properties): All GHS physical hazard classes from the seventh revised edition, except the Explosives and Desensitized Explosives hazard classes, have been adopted in Canada through the HPR. The Explosives and Desensitized Explosives hazard classes have not been adopted because, as specified in Schedule 1 of the HPA, explosives, as defined in section 2 of the Explosives Act, are excluded from the application of the HPA. The Chemicals Under Pressure hazard class from the eighth revised edition of the GHS has been adopted in the HPR. In addition, the following physical hazard classes, which are not included in the GHS, have been introduced through the HPR to enhance protections for workers: Combustible Dusts, Simple Asphyxiants, and Physical Hazards Not Otherwise Classified.
• Health hazards (which represent hazards to health arising from exposure to a substance or mixture): All GHS health hazard classes have been adopted in Canada in the HPR. The Biohazardous Infectious Materials (BIM) hazard class (which is not a GHS health hazard class) has been retained in the HPR in order to maintain worker protection. The BIM hazard class was part of WHMIS prior to the incorporation of the GHS. Additionally, a hazard class for Health Hazards Not Otherwise Classified has been introduced through the HPR to enhance worker protection.
• Environmental hazards (which represent hazards to the environment): The GHS environmental hazard classes have not been adopted in the HPR. This is because WHMIS covers workplace hazards associated with chemical substances, mixtures and products, as well as biohazardous infectious materials. Environmental hazards are not considered to be workplace hazards.

Suppliers need to be aware of the new requirements and changes to previous requirements when selling or importing hazardous products in Canada following the publication of amendments to the HPR on January 4, 2023.
The following is a summary of the key changes to WHMIS following the adoption of updates to align with the seventh revised edition of the GHS:

• New classification criteria for the Aerosols physical hazard class (formerly Flammable Aerosols), including the adoption of a new category for non-flammable aerosols
• New provision indicating that products classified in the Aerosols physical hazard class need not be classified in any category of the Gases Under Pressure physical hazard class
• Revised classification criteria for the Flammable Gases physical hazard class
• New definitions of terms used in the Flammable Gases physical hazard class
• Repeal of the Pyrophoric Gases physical hazard class (pyrophoric gases are included in Category 1A of the revised Flammable Gases physical hazard class)
• Expanded classification criteria for the Oxidizing Solids physical hazard class
• Amended definitions of terms used in some health hazard classes (acute toxicity, skin corrosion, skin irritation, serious eye damage, eye irritation, respiratory sensitization, skin sensitization and reproductive toxicity)
• New definitions for germ cell mutagenicity and carcinogenicity
• Amended classification criteria for skin corrosion
• New information elements required on SDSs
• Additional or revised precautionary statements for certain hazard classes and categories or subcategories

In addition, there is a key change to WHMIS adopted from the eighth revised edition of the GHS:

• Introduction of a new physical hazard class for Chemicals Under Pressure

Supplier obligations

Canadian suppliers of hazardous products must comply with the requirements of the HPA and the HPR, as administered by Health Canada. Importers of hazardous products that are used directly in their own workplace are also governed by this legislation. The purpose of this guidance is to inform suppliers of these requirements.

Canadian suppliers of hazardous products are required to:

• Identify whether their products are hazardous products
• Prepare or obtain bilingual labels and SDSs
• Affix a label to a hazardous product and provide the SDS to the purchaser of a hazardous product
• Prepare and maintain documents, including copies of labels and SDSs, as well as sales and purchasing information, and provide these documents to the Minister or an inspector on request
• Update SDSs and labels within 90 and 180 days, respectively, of a supplier becoming aware of "significant new data" (that is, information which changes the classification of the hazardous product or the ways to protect against the hazards presented by the product)
• Disclose any information required to appear on an SDS to a safety or health professional, in an emergency

With the exception of CBI claims administered under the HMIRA (refer to Appendix A for further information), there is no pre-market approval mechanism or registration requirement under the HPA.

Employers and workers should consult their occupational health and safety jurisdiction for information on their obligations and WHMIS requirements.

Exclusions

The WHMIS supplier hazard communication requirements do not apply to certain products sold or imported for use, handling or storage in Canadian workplaces.

The exclusions to supplier requirements under the HPA and the HPR are:

• Explosives as defined in the Explosives Act
• Cosmetics, devices, drugs or foods, as defined in the Food and Drugs Act
• Pest control products as defined in the Pest Control Products Act
• Consumer products as defined in the Canada Consumer Product Safety Act
• Wood or products made of wood
• Nuclear substances within the meaning of the Nuclear Safety and Control Act, that are radioactive
• Hazardous waste being a hazardous product that is sold for recycling or recovery and is intended for disposal
• Tobacco and tobacco products as defined in the Tobacco and Vaping Products Act
• Manufactured articles

Comparison to Transportation of Dangerous Goods

The federal Transportation of Dangerous Goods Act (TDG Act) is not the same as the WHMIS legislation. The TDG Act protects the general public from hazards associated with transporting dangerous materials on public roads, in the air, by rail, or on waterways. In contrast, WHMIS protects the health and safety of workers at workplaces by requiring that product hazard information be provided to employers and workers to promote the safe handling and use of these products in the workplace. The 2 systems often deal with the same chemicals, but the TDG Act addresses their transport and WHMIS addresses their use, handling, and storage in workplaces.

Canada-U.S. cooperation under the Regulatory Cooperation Council

Adopting the GHS fulfilled the Canada-U.S. Regulatory Cooperation Council (RCC) commitment to align and synchronize implementation of common classification and labelling requirements for workplace hazardous chemicals. Consistent with the overall objectives of the RCC and as part of the Canada-U.S. RCC Joint Forward Plan, Health Canada collaborated with U.S. OSHA to implement updates to the GHS (that is, the seventh revised edition) within the 2 countries' respective legislative frameworks. Together, Health Canada and U.S. OSHA continue to promote ongoing alignment of hazard classification and communication requirements for workplace chemicals, without reducing the level of safety or of protection to workers.

Health Canada and U.S. OSHA collaborated to keep the variances between the 2 countries to a minimum. However, there are some regulatory variances between the 2 countries that are necessary in order to maintain the previous level of protection for workers or due to the requirements of the respective legislative frameworks.

Canada and the U.S. have each agreed to accept the additional information required by the other. It is therefore possible to meet both Canadian and U.S. requirements for a hazardous product using a single label and SDS. Such labels and SDSs would have to meet the requirements for each country. It is important to note, however, that an SDS and label that are compliant with the HCS may not be sufficient for compliance in Canada; suppliers selling or importing hazardous products intended for use, handling or storage in Canadian workplaces must be compliant with the Canadian requirements.

In 2019, Health Canada and U.S. OSHA collaborated to produce joint guidance, intended to communicate information related to both Canadian and U.S. labelling requirements for hazardous products under the Canadian HPR and the U.S. HCS. This guidance includes:

• Joint Occupational Safety and Health Administration/Health Canada Guidance on Regulatory Processes for Hazardous Products in the Workplace
• Joint Occupational Safety and Health Administration/Health Canada Comparison of Labelling Requirements for Hazardous Products
• Joint Occupational Safety and Health Administration/Health Canada Guidance on Labelling Pictogram for Hazards Not Otherwise Classified, Physical Hazards Not Otherwise Classified and Health Hazards Not Otherwise Classified

For further information, please see Summary: Joint Health Canada and United States Occupational Safety and Health Administration Guidance.

Health Canada and U.S. OSHA will continue to collaborate to develop joint guidance material for hazard classification and communication requirements.

Hazardous Products Act

Interpretation

The Hazardous Products Act (HPA) is divided into Parts I, II, and III. Part I of the HPA was repealed in 2010 with the enactment of the Canada Consumer Product Safety Act (CCPSA). The definitions in section 2 of the HPA apply to Parts II and III. In addition, the terms defined by the HPA retain that meaning in the Hazardous Products Regulations (HPR). For additional information, please consult the HPA.

Discussion of section 2 of the Hazardous Products Act

As specified in subsection 21(1) of the HPA, the Minister of Health may designate an "analyst" for the purposes of the administration and enforcement of any provision of the HPA or of the HPR. An analyst can be any individual or class of individuals. However, if the individual is employed by a provincial government, or a public body established under an Act of the legislature of a province, the Minister may make the designation only after obtaining the approval of that government or public body.

The definition of "container" is not exhaustive. In other words, a "container" under the HPA is not limited to the items specifically listed in the definition. Dictionary definitions of the term "container" refer to:

• "an object (such as a box or can) that can hold something"
• "a receptacle for holding goods"
• "anything that contains or can contain something such as a carton, box, crate or can"
• "an object used for or capable of holding, especially for transport or storage, such as a carton, box, etc."

Therefore, almost any type of packaging could be considered as a container, including shrink wrap.

"Storage tank" is not a defined term in the HPA. However, based on dictionary definitions, this term refers to large containers, vessels or reservoirs that can hold and store liquids or gases. They are usually permanently installed on a work place premises, sometimes underground. Safety requirements pertaining to work place storage tanks fall under the federal, provincial and territorial authority to make occupational health and safety legislation. Storage tanks are not subject to requirements under the HPA. However, if a storage tank is mounted on a truck, it may no longer be excluded from the definition of container since it may be considered a portable tank.

The term "document" refers to anything on which information that is recorded or marked can be understood by a human being or can be read by a device such as letters, numbers and images (symbols) on a paper document or on a microfilm as well as in electronic documents such as emails, Word, Excel or PDF documents. Electronic documents could be provided on storage devices such as compact discs, USB flash drives or portable hard drives. Under the HPA, a "safety data sheet" (SDS) is, by definition, a document.

Under the HPA, a "hazardous product" is a product, mixture, material or substance that is classified according to the criteria set out in the HPR in a category or subcategory of at least 1 of the health hazard or physical hazard classes listed in Schedule 2 of the HPA. The HPR are currently the only regulations made under subsection 15(1) of the HPA.

There are 4 important terms used in this definition: product, mixture, material and substance (also referred to as PMMS). The terms "mixture" and "substance" are defined in the HPA (see below).

• The term "material" is not defined in the HPA, but under the HPR, it is generally used in the context of Biohazardous Infectious Materials.
• The term "product" is not defined, but is used in the HPR in sections relating to physical hazard classes such as Aerosols and Gases Under Pressure, where the packaging of the mixture, material or substance, as well as the contents of the packaging, must be considered for the purpose of classification. That is, a mixture, material or substance in its package is considered to form a product and it is the overall product that is classified.

To "import" means to bring into a country from another country. This definition is specific to importation into Canada. A person who, in the course of business, brings into Canada a hazardous product intended for use, handling or storage in a work place, from another country, is importing. The importer, therefore, is a "supplier" under the HPA.

As specified in subsection 21(1) of the HPA, the Minister of Health may designate an "inspector" for the purposes of the administration and enforcement of any provision of the HPA or of the HPR. An inspector can be any individual or class of individuals. However, if the individual is employed by a provincial government, or a public body established under an Act of the legislature of a province, the Minister may make the designation only after obtaining the approval of that government or public body.

The definition of "label" includes the different means of providing labelling for a hazardous product and different types of characters including letters, numbers and pictograms. The group of required information elements that constitute the label of a hazardous product may be printed directly on the hazardous product, that is, printed on the unpackaged hazardous product, or printed directly on the container in which the hazardous product is packaged. The group of required information elements may also be printed on a support, such as self-adhesive paper or a plastic sleeve which are respectively affixed or attached to the container.

Specific details on label requirements can be found in Part 3 of this guidance. As required by section 3.4 of the HPR, the required information elements of the label of a hazardous product must be clearly and prominently displayed on a surface that is visible under normal conditions of use, be easily legible without the aid of any device other than corrective lenses, and be contrasted with any other information on the hazardous product or the container.

The definition of "manufactured article" is linked to an exclusion found in paragraph 12(i) of the HPA. If an article meets this definition, it is not subject to any requirements under the HPA. Whether an article meets the definition of a manufactured article must be assessed on a case-by-case basis.

"Normal conditions of use" means the normally expected conditions under which the article is employed for its intended purpose, and excludes the maintenance or repair of the article as well as the mishandling or misuse of the article. To be exposed to a hazardous product means to be exposed to amounts or levels of the hazardous product in a sufficient quantity to pose a hazard. It does not include acute or chronic exposure to minute or trace amounts that do not pose a physical or health risk to workers.

Examples:

An industrial mercury thermometer is a manufactured article. Although it contains a hazardous product, under normal conditions of use, mercury is not expected to be released and a worker would not be exposed to that substance. An industrial mercury thermometer is, therefore, excluded from the requirements of the HPA.

An industrial refrigerator is a manufactured article made up of various components including a system for containing gases under pressure, which are hazardous products. During installation and under normal conditions of use, the gases are not expected to be released and a worker would not be exposed to these gases. An industrial refrigerator is, therefore, excluded from the requirements of the HPA.

An industrial welding rod may or may not be a manufactured article. An industrial welding rod that releases a hazardous product under normal conditions of use is not a manufactured article and cannot be excluded from the requirements of the HPA on that basis.

In the HPA and throughout this document, the term "Minister" means the Minister of Health.

A "mixture" is the result of the combination of at least 2 different ingredients that do not react with each other. Each ingredient in the mixture must remain present in the same proportion as when it was initially introduced to create the mixture. The ingredients could be liquids, solids or gases.

It is important to clearly identify if the hazardous product that is to be classified is a substance or a mixture. The classification rules in the HPR may be different for a substance versus a mixture. It is important to note that a "complex mixture" is a term defined in subsection 5.6(1) of the HPR.

As indicated in this definition a "person" can be an "individual", or an organization as defined in section 2 of the Criminal Code.

As defined in section 2 of the Criminal Code, "organization" means:

• a public body, body corporate, society, company, firm, partnership, trade union or municipality, or
• an association of persons that
  • is created for a common purpose,
  • has an operational structure, and
  • holds itself out to the public as an association of persons;

To date, the only regulations made under subsection 15(1) of the HPA are the HPR. No regulations have been made under section 27 of the Act. The expression "prescribed by the regulations" should be understood as meaning the same as "as required by the regulations".

Note: The definition of the term "prescribed" appears only in the English version of the HPA. The French version of the HPA uses a different drafting technique to express the same concept.

As specified in section 26.2 of the HPA, the Minister of Health may designate as a "review officer" any individual or class of individuals who, in the Minister's opinion, is qualified to be so designated, for the purposes of reviewing, under section 26.3 of the HPA, ministerial orders made under section 26.1 of that Act.

The HPR set out the requirements for information elements to appear on a safety data sheet (SDS), including headings. These SDS content requirements are designed to provide information on the hazards presented by a hazardous product, as well as precautionary measures that apply to the use, handling and storage of the product. The SDS provides more detailed information about a hazardous product than the label. The requirements for the provision of information on SDSs are set out in Part 4, Schedule 1 and Schedule 2 of the HPR. As specified in subsection 6.2(1) of the HPR, the information elements provided on an SDS must always be in both official languages of Canada (English and French).

The definition of "sell" begins with the word "includes", so the meaning attributed to the term "sell" by paragraphs (a) and (b) should be understood as being additional to the ordinary meaning of "sell". The definition of "sell" in section 2 of the HPA captures 9 distinct actions, namely:

1. selling – according to the regular meaning of sell
2. distributing, whether for consideration or not
3. making any transfer of possession that creates a bailment (or, in Quebec, making any transfer of possession of a movable for a specific purpose without transferring ownership and with the obligation to deliver the movable to a specified person or to return it)
4. offering for sale
5. offering for distribution
6. exposing for sale
7. exposing for distribution
8. having in possession for sale
9. having in possession for distribution

The definition specifies that distribution is a form of sale whether the distribution is for consideration or not. Based on this definition, a distribution or give-away of the hazardous product as a sample, prize or a "free" item is, therefore, included in the definition of "sell".

In the context of the HPA, the term "distribute" does not include internal movement of a product within an organization, but does include transfers of a product between independent organizations as well as between separate subsidiaries of a parent corporation, or between a subsidiary and its parent corporation.

The term "consideration" includes money as well as services or goods for exchange without using money (that is, bartering). The term "recipients" refers to individuals (that is, human beings), organizations (which includes companies), and governments that receive a hazardous product upon sale or distribution.

Where a hazardous product, such as a laboratory sample, is supplied to a work place by the same entity that operates the work place, the supply of that hazardous product is not governed by the HPA. However, in such circumstances, the provision of safety information to workers falls under federal, provincial and territorial occupational health and safety legislation. On the other hand, where a hazardous product is supplied to a work place by a different entity than the operator of the work place, then the supplier of the hazardous product is "distributing" the said product under the HPA. Consequently, the supplier, in this case, is required to comply with the requirements of the HPA and the HPR.

Paragraph (b) of the definition of "sell" specifies that any transfer of possession that creates a bailment is included in the Act's definition of "sell". A bailed product is a product in relation to which there is a transfer of possession but not a transfer of ownership (for example, a laboratory sample sent for analysis or a product provided to a third party for packaging, whereby the third party does not have ownership of the sample or product). It is important to note that when a hazardous product is moved between departments within the same work place of an employer, it is not considered to be a bailment since possession and ownership of the hazardous product remain with the employer.

The term "bailment" is a common law concept. However, the province of Quebec also operates under civil law. While the term "bailment" is not used in civil law, an equivalent concept exists in Quebec. Therefore, as part of the definition of "sell", it was necessary to describe the equivalent of "bailment" under civil law, that is, "in Quebec, make any transfer of possession of a movable, for a specific purpose, without transferring ownership, and with the obligation to deliver the movable to a specified person or to return it, such as a transfer by means of a deposit, a lease, a pledge, a loan for use or a contract of carriage;".

All naturally occurring and synthetic chemical elements can be found in the periodic table. Examples of naturally occurring chemical elements are calcium (Ca), titanium (Ti), carbon (C), or helium (He). A chemical compound consists of 2 or more different chemical elements that are associated via chemical bonds, for example, acetone ((CH₃)₂CO), propane (C₃H₈), sodium hydroxide (NaOH), toluene (C₇H₈), water (H₂O), or zinc chloride (ZnCl₂).

The term "substance" refers, in principle, to a single entity (for example, ammonia, silver nitrate, or toluene). However, the definition of "substance" in the HPA considers that a substance may have small amounts of stabilizing additives, impurities and stabilizing solvents. Impurities, stabilizing solvents, or stabilizing additives may have their own unique hazards and/or may contribute to the hazards of the substance.

Therefore, for the purposes of hazard classification under the HPR, impurities, stabilizing solvents, or stabilizing additives that are, by themselves, classified in a category or subcategory of a health hazard class and that are present in a substance at a concentration above the corresponding concentration limit must be considered for the classification of the substance. Further information can be found in Part 2 of this guidance.

Under the HPA, manufacturers, importers or distributors, including retailers, of a hazardous product are all considered "suppliers".

The term "manufacturer" is defined in subsection 1(1) of the HPR as follows: "manufacturer" means a supplier who, in the course of business in Canada, manufactures, produces, processes, packages or labels a hazardous product and sells it. For more information about this definition, refer to Part 1 of this guidance. A manufacturer is different from an importer. An importer is a supplier who brings a hazardous product into Canada, but does not sell the product. Where a foreign supplier sells and ships a hazardous product directly to a Canadian customer, that Canadian customer is the Canadian importer. If an importer modifies a hazardous product that they imported (for example, by repackaging or relabeling it) and subsequently sells the modified hazardous product, then the importer meets the definition of a "manufacturer" under the HPR.

A manufacturer is also different from a distributor. A distributor is a Canadian supplier to whom a hazardous product was sold, who resells the hazardous product without modifying it in any way. This includes a retailer. If a distributor does modify a hazardous product that they purchased (for example, by repackaging or relabeling it) and subsequently sells it, then the distributor meets the definition of a "manufacturer" under the HPR.

The HPR includes definitions for the terms "initial supplier identifier" (subsection 1(1)), "first supplier" and "subsequent supplier" (subsection 5.7(1)). Further guidance on these terms can be found in Part 1 and Part 5 of this guidance.

To date, the only regulations made under subsection 15(1) of the HPA are the HPR. Under the HPR, "work place" is defined in subsection 1(1) as follows: "means a place where a person works for remuneration." For more information about this definition, refer to Part 1 of this guidance.

Part II

Hazardous products

Discussion of section 12 of the Hazardous Products Act

Application

There are certain products that do not fall under the scope of the HPA. The products listed in paragraphs 12(d) through (i) are not subject to requirements under the HPA and HPR.

In addition, the amendments to the HPA in 2014 included the introduction of Schedule 1 to the Act, which is referred to in paragraph 12(j). This Schedule lists excluded items that were previously mentioned in former paragraphs 12 (a), (b), (c), (f) and (g), respectively:

1. Any pest control product as defined in subsection 2(1) of the Pest Control Products Act
2. Any explosive as defined in section 2 of the Explosives Act
3. Any cosmetic, device, drug or food, as defined in section 2 of the Food and Drugs Act
4. Any consumer product as defined in section 2 of the Canada Consumer Product Safety Act
5. Any wood or product made of wood

These products do not fall under the scope of the HPA and therefore are not subject to the requirements under the HPA and the HPR. In the future, the products listed in Schedule 1 to the HPA may be considered for inclusion under the HPA following the regular regulatory process.

Paragraph 12(d)

The definition of "nuclear substance" is found in the Nuclear Safety and Control Act(NSCA), and includes only the radioactive components of radioactive nuclide mixtures. As a result, non-radioactive hazardous product carrier materials in radioactive nuclide mixtures are subject to the requirements of the HPA. However, there are labelling and SDS exemptions for mixtures of radioactive nuclides and non-radioactive carriers under subsections 5.1(1), 5.1(2) and 5.1(3) of the HPR. Refer to Part 5 of this guidance for additional information on these exemptions. Note that the HPA labelling requirements for non-radioactive carrier materials for radioactive nuclides are in addition to, and separate from, any labelling requirements for radioactive nuclides under the NSCA.

Paragraph 12(e)

By virtue of paragraph 12(e) of the HPA, hazardous waste is exempt from the requirements of the HPA. While hazardous waste is not a defined term in section 2 of the Act, paragraph 12(e) provides the meaning of this term as follows:
"... being a hazardous product that is sold for recycling or recovery or is intended for disposal."

Some hazardous products are recovered and then either re-used or recycled and then sold as a recycled product with or without further processing. Paragraph 12(e) does not establish an exemption for hazardous products that are recycled and then sold to another work place. Only hazardous waste that is "intended for disposal" or is "sold for recycling or recovery" falls within the definition of hazardous waste and is thereby exempt from the requirements of the HPA.

Paragraph 12(h)

The definition of "tobacco product" is found in section 2 of the Tobacco and Vaping Products Act.

Paragraph 12(i)

The definition of "manufactured article" in section 2 of the HPA is discussed earlier in this chapter.

An article that meets the conditions stated in the definition is excluded from the requirements of the HPA. The manufactured article definition refers to the release of or exposure to a hazardous product "under normal conditions of use". "Normal conditions of use" means the normally expected conditions under which the article is employed for its intended purpose, and excludes the maintenance or repair of the article as well as the mishandling or misuse of the article. If under normal conditions of use, hazardous products are released from the manufactured article only in trace amounts that would not pose a health risk to workers the article still falls under the "manufactured article" exemption.

If a hazardous product that is an article is not exempt from the application of the HPA under the manufactured article exclusion because, under normal conditions of use, it releases a hazardous product, the supplier must provide information in relation to those substances or mixtures that are hazardous products and that are released under normal conditions of use, in the appropriate section(s) of the SDS. In addition, hazard information related to hazardous decomposition products and hazardous combustion products (which are hazardous products) released during normal use, which are known to the supplier, must also be disclosed on the SDS. Finally, paragraph 4(1)(c) of the HPR requires that the supplier provide on the SDS all additional hazard information that is available with respect to the hazardous product or a product, mixture, material or substance that has similar properties.

The words "to be exposed to a hazardous product" at the end of the manufactured article definition do not necessarily refer only to a hazardous product which is present in the article that is sold or imported. These words also refer to hazardous products that are released as a result of thermal or chemical degradation. Where a hazardous product that is present in the article is released during normal use but in an altered form that is also a hazardous product (for example, an oxide), the manufactured article exclusion cannot be used.

Paragraph 12(j) / Schedule 1

Section 1 of Schedule 1

The definition of "pest control products" is found in subsection 2(1) of the Pest Control Products Act(PCPA).

Section 2 of Schedule 1

The definition of "explosive" is found in section 2 of the Explosives Act. The Explosives hazard class and the Desensitized Explosives hazard class from the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) were not adopted in the HPR as a result of this exclusion.

Section 3 of Schedule 1

The definitions of "cosmetic", "device", "drug" and "food" are found in section 2 of the Food and Drugs Act(FDA).

Section 4 of Schedule 1

The definition of "consumer product" is found in section 2 of the CCPSA.

Section 5 of Schedule 1

There is no regulatory definition of "any wood or product made of wood". Examples of wood and products made of wood include:

Wood board, beam or plank, fuel wood, wood in chips or particles, sawdust/wood waste and scrap, bark, fire logs, wood shavings, logs, wood wool/wood flour, lumber, wood pellets, veneer sheets, particleboard, fiberboard, plywood, parallam wood, oriented strandboard, waferboard, laminated beams, and densified wood.

Prohibitions

Discussion of subsection 13(1) of the Hazardous Products Act

Paragraphs 13(1)(a), (a.1) and (b) of the HPA refer to SDS and labelling requirements.

Guidance on labelling and SDS requirements can be found in Part 3 and Part 4 of this guidance.

Based on the definition of "sell" in section 2 of the HPA, the term "sell" captures 9 distinct actions. Three of them (numbers 1 -3 in the list below) involve a transfer of ownership or possession, and 6 of them do not (numbers 4 – 9 in the list below):

1. selling – according to the regular meaning of sell
2. distributing, whether for consideration or not
3. making any transfer of possession that creates a bailment
4. offering for sale
5. offering for distribution
6. exposing for sale
7. exposing for distribution
8. having in possession for sale
9. having in possession for distribution

Paragraph 13(1)(a) of the HPA specifies that suppliers who sell (that is, who undertake any of the actions above) a hazardous product that is intended for use, handling or storage in a work place in Canada are required to have in their possession an SDS for the hazardous product that meets the requirements of the HPR.

Upon sale of a hazardous product that is intended for use, handling or storage in a workplace in Canada, a supplier must provide the SDS to the person or government who received the hazardous product, as per paragraph 13(1)(a.1) of the HPA. This paragraph specifies that this requirement applies only in circumstances where "the person or government acquires possession or ownership of that hazardous product". Therefore, paragraph 13(1)(a.1) applies to actions that include selling (according to the regular meaning of sell), distributing and making any transfer of possession that creates a bailment - items 1, 2 and 3 in the list above. When the supplier undertakes any of those three actions, they have the obligation to provide (or cause to be provided) an SDS (that is compliant with the requirements of the HPR) to the person or government who acquires possession or ownership of the hazardous product. It must be noted that subsection 13(1) is a prohibition; it is prohibited for a supplier to accomplish any of the above three actions if the supplier does not provide (or cause to be provided) an SDS that is compliant with the requirements of the HPR.

The obligation to provide an SDS occurs on the sale of the hazardous product when the person or government obtains the possession or ownership of the product. As a result, the obligation to provide an SDS exists even in situations where the transfer of the ownership occurs before the transfer of possession (for example, a sale contract regarding a hazardous product that is agreed to by the parties prior to delivery of the product). Since the sale always occurs before workers begin any use, handling or storage of the hazardous product in the work place, this requirement helps to ensure that the SDS will be in the hands of the person or government who acquires possession or ownership of the hazardous product before any potential exposure to the hazardous product could occur.

Paragraph 13(1)(b) of the HPA specifies that no supplier shall sell a hazardous product that is intended for use, handling or storage in a work place in Canada unless the hazardous product or the container in which the hazardous product is packaged has an HPR compliant label affixed to it, printed on it or attached to it in a manner that meets the requirements of the HPR. This requirement applies in each of the 9 situations that are encompassed by the definition of "sell" in section 2 of the HPA. Thus, for example, when a supplier sells a hazardous product (according to the regular meaning of sell), or exposes for sale or has in possession for sale a hazardous product that is intended for use, handling or storage in a work place in Canada, the labelling requirement set out in paragraph 13(1)(b) of the HPA must be met.

In Part 5 of the HPR, there are some provisions that, under specified conditions, set out exemptions from the application of paragraph 13(1)(a), (a.1) or (b), or paragraphs 13(1)(a) and (a.1) of the HPA.

There are also some provisions that, under specified conditions, set out exemptions from the application of section 13 of the HPA. Refer to Part 5 of this guidance for additional information.

Note that subsection 13(1) of the HPA is subject to the Hazardous Materials Information Review Act (HMIRA), which prescribes the types of information that may be eligible for a trade secret claim, and defines the structure and function of the claims process.

Discussion of subsection 13(2) of the Hazardous Products Act

The term "government" is used in the context of paragraph 13(1)(a.1) of the Act, which refers to "the sale of a hazardous product to any person or government …".

The term "province", used in paragraph 13(2)(c) of the Act, means a province of Canada, and includes Yukon, the Northwest Territories and Nunavut.

According to subsection 13(3) of the Access to Information Act the term "aboriginal government" means

1. Nisga'a Government, as defined in the Nisga'a Final Agreement given effect by the Nisga'a Final Agreement Act;
2. the council, as defined in the Westbank First Nation Self-Government Agreement given effect by the Westbank First Nation Self-Government Act;
3. the Tlicho Government, as defined in section 2 of the Tlicho Land Claims and Self- Government Act;
4. the Nunatsiavut Government, as defined in section 2 of the Labrador Inuit Land Claims Agreement Act;
5. the council of a participating First Nation as defined in subsection 2(1) of the First Nations Jurisdiction over Education in British Columbia Act;

   (e.1) the Tla'amin Government, as defined in subsection 2(2) of the Tla'amin Final Agreement Act;

6. the Tsawwassen Government, as defined in subsection 2(2) of the Tsawwassen First Nation Final Agreement Act;

   (f.1) the Cree Nation Government, as defined in subsection 2(1) of the Cree Nation of Eeyou Istchee Governance Agreement Act or a Cree First Nation, as defined in subsection 2(2) of that Act;

7. a Maanulth Government, within the meaning of subsection 2(2) of the Maanulth First Nations Final Agreement Act;
8. Sioux Valley Dakota Oyate Government, within the meaning of subsection 2(2) of the Sioux Valley Dakota Nation Governance Act; or
9. the council of a participating First Nation, as defined in section 2 of the Anishinabek Nation Education Agreement Act.

Discussion of section 14 of the Hazardous Products Act

Under section 14 of the HPA, a Canadian supplier who imports a hazardous product intended for use, handling or storage in a work place in Canada must obtain or prepare, on or before the importation, an SDS for the hazardous product that meets the requirements of the HPR. In addition, they must ensure that a label that meets the requirements of the HPR has been affixed to, printed on or attached to the hazardous product or the container in which the hazardous product is packaged, in a manner that meets the requirements of the HPR.

Guidance on labelling and SDS requirements can be found in Part 3 and Part 4 of this guidance.

It must be noted that, under the HPA, there is no obligation for a foreign supplier of a hazardous product to provide an SDS or label. The HPA applies only to sales and importations of hazardous products in Canada. Where a foreign supplier sells and ships a hazardous product directly to a Canadian customer, that Canadian customer is the Canadian importer and becomes the regulated party who is subject to the requirements of the HPA, provided that the importation is made in the context of the importer's course of business. The Canadian importer – not the foreign supplier – is responsible for ensuring that the label and SDS of the hazardous product are in compliance with the requirements of the HPA and the HPR.

A Canadian importer of a hazardous product that is intended for use, handling or storage in a work place in Canada who does not obtain an SDS that is compliant from the foreign supplier, on or before importation, must prepare a compliant SDS, on or before the importation of the hazardous product, in order to comply with section 14 of the HPA.

In addition, paragraph 14(b) requires that the imported hazardous product or its container be labelled according to the applicable requirements of the HPR on or before the importation. However, an importer may use the exemption provided in subsection 5.15(1) of the HPR which allows the Canadian importer to import hazardous products that are not labelled according to the HPR if the hazardous products are imported for the purpose of being brought into compliance with the labelling requirements of the HPR before they are used or sold.

In Part 5 of the HPR, there are some provisions that, under specified conditions, set out exemptions from the application of section 14 or paragraphs 14(a) or (b) of the HPA. Refer to Part 5 of this guidance for additional information.

Note that section 14 of the HPA is subject to the HMIRA, which prescribes the types of information that may be eligible for a trade secret claim, and defines the structure and function of the claims process.

Discussion of section 14.1 of the Hazardous Products Act

Subsections 14.1(1) and (2) of the HPA, subject to the HMIRA, prohibit the sale and importation of hazardous products that contain asbestos and are intended for use, handling or storage in a work place in Canada, unless:

• the supplier meets the SDS and label requirements that apply to hazardous products under the HPA and HPR and
• the hazardous products meet the requirements of any asbestos-specific regulations made under subsection 15(2) of the HPA

Subsection 15(2) of the HPA provides authorities for the Governor in Council to make regulations respecting the sale or importation of hazardous products containing asbestos and that are intended for use, handling or storage in a work place in Canada.

Since there are currently no asbestos regulations made under subsection 15(2), hazardous products that contain asbestos that are intended for use, handling or storage in a work place in Canada must meet the applicable labelling and SDS requirements of the HPA and the HPR to be sold or imported in Canada.

Discussion of section 14.2 of the Hazardous Products Act

Subsections 14.2(1), (2) and (3) of the HPA prohibit suppliers from selling or importing a hazardous product that is intended for use, handling or storage in a work place in Canada, if the label or SDS for the hazardous product contains information that is false, misleading or likely to create an erroneous impression with respect to the information required to be included in a label or SDS for that hazardous product.

Subsection 14.2(4) of the HPA prohibits a supplier who sells a hazardous product intended for use, handling or storage in a work place in Canada from communicating, by any means, in the course of selling the hazardous product, any information about the hazardous product that is false, misleading or likely to create an erroneous impression with respect to the information required to be included in a label or SDS for that hazardous product. This prohibition includes information on a supplier website or in technical documents made available or communicated to the public.

An example of false or misleading information could be a label of a hazardous product that bears the required precautionary statement "Wear protective gloves/protective clothing/eye protection/face protection", and also depicts a worker having direct contact (with bare hands) with a hazardous product classified in Skin Corrosion – Category 1C. This image could be misleading and create an erroneous impression with regard to the manner of handling the hazardous product. Furthermore, it contradicts the precautionary statement provided on the label.

Additional information beyond what is required under the HPR may be included on the label and the SDS as long as the information is not false, misleading, or likely to create an erroneous impression with respect to information that is required under the HPR. For example, a supplier may include information in languages other than English and French on the label and SDS, as long as the information conveyed in these additional languages is not false, misleading or likely to create an erroneous impression.

Preparing and maintaining documents

Discussion of section 14.3 of the Hazardous Products Act

Section 14.3 of the HPA requires suppliers of hazardous products intended for use, handling or storage in a work place in Canada to prepare and maintain documents, including true copies of labels and SDSs, as well as sales and purchasing information. These documents must be provided to the Minister or an inspector on written request. Section 14.3 also addresses the period for keeping documents and the location where they must be kept.

Documents that must be prepared and maintained may be similar to those that businesses already retain as part of their normal bookkeeping practices. Under section 14.3, suppliers must prepare and maintain the following:

• A document containing a true copy of the label in both official languages (English and French), unless the label is not required as a result of an exemption under the HPR (for example, sale or importation of a bulk shipment or a hazardous product without packaging of any sort)
• A document containing a true copy of the SDS in both official languages (English and French);
• A document indicating the name and address of the person from whom the supplier obtained the hazardous product, the quantity of the hazardous product obtained, and the month and year in which the supplier obtained it
• For any sales of the product that resulted in a transfer of ownership or possession, a document indicating the locations at which sales took place (that is, the address of the place of business of the supplier), the period during which sales took place (for example, from June 1, 2015 to May 23, 2016), and, for each month in that period, the quantity sold during the month (for example, June 2016 = 60 units; July 2016 = 234 tons; August 2016 = 6234 L)

The specific information concerning the names and addresses of customers who purchased the hazardous product is not required to be maintained under subsection 14.3(1). However, if available, this information may be obtained by an inspector using powers granted under subsection 22(1) of the HPA.

In addition to the most up-to-date version of the label and SDS of the hazardous product, older versions of the label and SDS must also be maintained for the prescribed period of time.

A "true copy" means that the copy must accurately reflect (shape, size, colour, etc.) the actual label and SDS.

These documents must be maintained for 6 years after the end of the year to which they relate, unless regulations specify another time period. To date, no other period has been prescribed in regulations. This time period aligns with existing document retention requirements that suppliers may already be required to meet, such as those under the federal Income Tax Act.

Documents can be maintained in paper or electronic format, but they must be kept at a supplier's place of business in Canada. Suppliers may determine the business location of those records, at their discretion. Regardless of where those documents are kept, it is important that they be accessible and that suppliers be able to provide them to the Minister or an inspector upon written request and within the specified manner and time period.

Subsection 14.3(4) of the HPA allows the Minister to exempt a supplier from the requirement to keep documents at their place of business in Canada if the Minister considers that keeping documents in Canada is unnecessary or impractical. Requests for an exemption from this requirement will be reviewed on a case-by-case basis and should be submitted in writing to Health Canada.

The documents provided to the Minister or an inspector upon written request should be legible and clearly identify the required information.

As specified in subsection 6.2(1) of the HPR, the information elements provided on an SDS and label must always be in both official languages of Canada (English and French). Therefore, the true copy of the label and SDS to be maintained as per paragraphs 14.3(1)(a) and (b) of the HPA must be bilingual (that is, English and French). As a result, the Minister or an inspector could require the true copy of the English or French portion of the label or SDS, or the true copy of the bilingual SDS or label. However, with regard to the documents to be maintained under paragraphs 14.3(1)(c) and (d) of the HPA and that may be required by the Minister or an inspector, the supplier can provide the document written in English or French.

Subsection 14.3(3) also stipulates that suppliers shall, on written request, provide documents to the Minister within the time and in the manner (for example, printed on paper or in an electronic format) specified in the request. Suppliers must provide the required records within the timelines set out in the written request.

Furthermore, as part of an inspection, an inspector may request, in writing, access to documents that are required to be maintained pursuant to subsection 14.3(1) of the HPA. Suppliers must provide the required documents to an inspector within the time and in the manner specified in the request.

Hazardous Products Regulations

Part 1 Interpretation

Part 1 of the Hazardous Products Regulations (HPR) provides the definitions for terms that are used in the regulations. This Part of the guidance provides additional information and some examples of the application and use of these definitions. It is important to note that some terms are not defined in Part 1 if the term is only used in a specific Part or Subpart of the HPR. Definitions for these terms can instead be found in the specific Part or Subpart of the HPR where the terms are used, and further information is found in the guidance chapter corresponding to that Part or Subpart. In some cases, more information regarding the meaning of a specific term defined in this Part may be found in the specific Part or Subpart of the HPR where the defined term is used. Information regarding the terms defined in the Hazardous Products Act (HPA) can be found in the Hazardous Products Act section of this guidance.

Discussion of subsection 1(1) of the Hazardous Products Regulations

"Act" refers to the Hazardous Products Act which was amended by the Economic Action Plan 2014 Act, No. 1 to incorporate the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). These amendments received Royal Assent on June 19, 2014 and came into force on February 11, 2015.

"Aerosol dispenser" is a term used in subsection 2.3(8) (Aerosols bridging principle) and in Subpart 3 of Part 7 (Aerosols) of the HPR. In this hazard class, there are 2 defined types of aerosols:

1. spray aerosol
2. foam aerosol

Aerosol dispensers that are classified in the Aerosols hazard class are not required to be classified in the Flammable Gases, Gases Under Pressure, Flammable Liquids or Flammable Solids hazard classes (Subpart 2, 5, 6 or 7 of Part 7, respectively).

"ATE" is an acronym that is used in Subpart 1 of Part 8 (Acute Toxicity) and in paragraph 11(d) of Schedule 1 of the HPR. The term "acute toxicity estimate" could apply to:

1. a hazardous product that is a substance
2. a hazardous product that is a mixture
3. an ingredient in a hazardous product that is a mixture

An ATE could be any of the following:

• an LD₅₀ value
• an LC₅₀ value
• an acute toxicity point estimate
• a calculated value, for a mixture, that is determined using either the mathematical formula in section 8.1.5 of the HPR or the mathematical formula in section 8.1.6 of the HPR

An acute toxicity point estimate (ATPE) is a numerical value that is often determined if a formula in section 8.1.5 or 8.1.6 is used, in accordance with the table to section 8.1.7 of the HPR. The ATPE is an estimate of the lethal dose or lethal concentration of an ingredient in a mixture. It is established when the supplier does not know the LD₅₀ or LC₅₀ value of the ingredient, but knows either:

1. the range of values within which the LD₅₀ or LC₅₀ of the ingredient falls or
2. the acute toxicity hazard category into which the ingredient falls

Where there is no specific LD₅₀ or LC₅₀ value available for an ingredient in a mixture, determining the ATPE allows an acute toxicity value (that is, the ATPE value) for this ingredient to be used in the calculation of the ATE of the mixture, in accordance with section 8.1.5 or 8.1.6 of the HPR. The ATPE is also determined for a product that is a substance where an exact LD₅₀ or LC₅₀ is unavailable.

Note: the terms "LD₅₀" and "LC₅₀", mentioned in the definition of "ATE", are also defined in subsection 1(1) of the HPR.

More information with regard to ATE and ATPE, including a discussion on how to calculate these values, is found in the guidance chapter corresponding to Subpart 1 of Part 8 (Acute Toxicity).

"CAS registry number", also known as "CAS number", is a unique numerical identifier assigned by the Chemical Abstracts Service (CAS), a division of the American Chemical Society, to a chemical substance. For example, the CAS registry number of acetone is 67-64-1.

"Chemical name": The use of a chemical name along with a CAS registry number, where available, helps in the precise identification of a material or substance. Some examples of chemical names that would meet the definition include "1,4-dimethylbenzene" and "para-xylene". Although both chemical names refer to the same substance, both are internationally recognized and they clearly identify the substance. The chemical name of a material or substance could also be used as the "product identifier", which is required to be provided on the label and safety data sheet (SDS).

The definition of chemical name refers not only to the identity of a chemical substance, but also to the identity of biohazardous infectious materials, even though these materials are not traditionally regarded as chemicals. A "chemical name" of a biohazardous infectious material could be, for example: Streptococcus pneumonia or measles virus.

The chemical name and/or the CAS registry number of a material or substance may be used to locate more information regarding the material or substance using sources such as the following:

• SDSs, technical data sheets, and product safety bulletins
• OSHA Chemical Sampling Information pages
• The Merck Index
• ChemID

"Flash point" is used in Subpart 6 of Part 7 (Flammable Liquids) and in paragraph 9(h) of Schedule 1 of the HPR. As specified in subsection 7.6.1(3), the flash point of a liquid that is a substance must be obtained using an "appropriate closed-cup method" listed in paragraph 2.6.4.2.5 of the GHS, as amended from time to time. For a liquid that is a mixture, the flash point must be determined either by tests using an appropriate closed-cup method (paragraph 7.6.1(4)(a)) or by the use of an applicable calculation method (paragraph 7.6.1(4)(b)). It would be a good practice to state on the SDS the method used to obtain a flash point value, as different methods can yield different results.

"Gas": the criteria for a gas are outlined in the definition of "gas" in subsection 1(1) of the HPR. Hazard definitions and classification criteria in the physical and health hazard classes frequently refer to a physical state, either solid, liquid or gas. This definition of "gas" allows the supplier to determine if their product is a "gas" within the meaning of the HPR, whenever this term is used. If the hazardous product is not a "gas" as per this definition, then the definitions of "liquid" and "solid" should be reviewed to determine the physical state of the product for HPR classification purposes. In the definitions and classification criteria for the hazard classes, set out in Parts 7 and 8, where no mention is made with regard to physical state, it must be understood that the hazard class applies to all physical states.

The "GHS" is a document that is updated by the United Nations from time to time. Where the HPR refer to the GHS, they are referring to the seventh revised edition of the GHS published in 2017 (GHS). There are notable exceptions, which can be identified by the words "the GHS, as amended from time to time". While there are several instances where the acronym "GHS" is used in the HPR, it is most often used to refer to section 3 of Annex 3 of the GHS that lists the prescribed hazard communication elements (symbol, signal word, hazard statement and precautionary statements) for each category and subcategory of each GHS hazard class.

"Hazardous ingredient" is an ingredient in a mixture which, when evaluated as an individual substance against the criteria of all health hazard classes of the HPR, is classified in at least 1 category or subcategory of a health hazard class.

Hazardous ingredients that:

• are classified in any category or subcategory of a health hazard class and are present above the designated concentration limit; or
• are present at a concentration that contributes to the classification of a mixture in at least 1 category or subcategory of a health hazard class

are required to be disclosed under item 3 of the SDS.

The following definitions from the HPA apply to the definition of "hazardous ingredient".

"Hazard statement" includes a phrase assigned to a category or subcategory of a hazard class that describes the nature of the hazard presented by the hazardous product. For the hazard classes that were adopted from the GHS, except for the "Chemicals Under Pressure" hazard class, the hazard statement for each category or subcategory of each hazard class is prescribed in section 3 of Annex 3 of the GHS. For example, the hazard statement for Acute Toxicity — Oral — Category 1 is "Fatal if swallowed" and the hazard statement for Acute Toxicity — Oral — Category 4 is "Harmful if swallowed." For products classified as Chemicals Under Pressure — Category 1 or 2, the hazard statement is prescribed in section 3 of Annex 3 of the Globally Harmonized System of Classification and Labelling of Chemicals, Eighth revised edition. For products classified as Chemicals Under Pressure — Category 3, the hazard statement is "Chemical under pressure: May explode if heated", as specified in paragraph 3(1)(c.2) of the HPR.

The hazard statements for the hazard classes that are not covered by the GHS (Combustible Dusts, Simple Asphyxiants, Physical Hazards Not Otherwise Classified (PHNOC), Biohazardous Infectious Materials and Health Hazards Not Otherwise Classified (HHNOC)) are either prescribed or referred to in Schedule 5 of the HPR.

Specifically, the hazard statements for the hazard classes Combustibles Dusts and Simple Asphyxiants are prescribed in column 5 of Parts 1 and 2 of Schedule 5 of the HPR.

Parts 4 to 6 of Schedule 5 require a hazard statement for PHNOC, Biohazardous Infectious Materials and HHNOC, but the wording for the statement is not prescribed in Schedule 5 of the HPR. The supplier must provide an appropriate hazard statement that describes the nature of the hazard.

As permitted by subsection 3.2(3) of the HPR, hazard statements may be combined where appropriate, if the combination conveys the same information as would have been conveyed by each of the individual statements.

Except in the case of certain exemptions (refer to Part 5 of the guidance), the HPR does not allow the omission of hazard statements.

"Initial boiling point" is used in Subpart 6 of Part 7 (Flammable Liquids) and in paragraph 9(e) of Schedule 1. Both the flash point and the initial boiling point are required to classify a substance or mixture in Category 1 or 2 of the hazard class "Flammable Liquids". A flammable substance or mixture with a low boiling point is more likely to catch fire upon exposure to an ignition source, since it may emit vapours at temperatures that may be close to or within the ranges that may be encountered in work places.

"Initial supplier identifier" means the name, address and telephone number of either the Canadian manufacturer or the Canadian importer of a hazardous product.

Definitions of "manufacturer", "importer", "distributor" and "supplier"

The term "manufacturer" is defined, in subsection 1(1) of the HPR, as "a supplier who, in the course of business in Canada, manufactures, produces, processes, packages or labels a hazardous product and sells it". A manufacturer is different from an importer. An importer is a supplier who brings a hazardous product into Canada. Where a foreign supplier sells and ships a hazardous product directly to a Canadian customer, that Canadian customer is the Canadian importer. If an importer modifies a hazardous product that they imported (for example, by repackaging or relabeling it) and subsequently sells the modified hazardous product, then the importer meets the definition of a "manufacturer" under the HPR.

A manufacturer is also different from a distributor. A distributor is a Canadian supplier to whom a hazardous product was sold, who resells the hazardous product without modifying it in any way. If a distributor does modify a hazardous product that they purchased (for example, by repackaging or relabeling it) and subsequently sells it, then the distributor meets the definition of a "manufacturer" under the HPR.

The term "supplier" is defined, in section 2 of the HPA, as "a person who, in the course of business, sells or imports a hazardous product". Therefore, all of the above-mentioned parties (that is, a manufacturer, an importer or a distributor of a hazardous product) are considered as "suppliers" under the HPA.

Requirement to provide the initial supplier identifier on the SDS and label of a hazardous product and exceptions to this requirement

As specified in paragraphs 3(1)(b) and 4(1)(b) and Schedule 1 of the HPR, the initial supplier identifier (the name, address and telephone number of either the Canadian manufacturer or the Canadian importer) must be provided on the label and SDS of a hazardous product that is sold in or imported into Canada and intended for use, handling or storage in a Canadian work place, unless an exemption under Part 5 of the HPR applies. For information regarding the exemptions to the requirement to provide the initial supplier identifier on the label and SDS of a hazardous product, see the discussions of sections 5.8 and 5.9 of the HPR in Part 5 of the guidance.

With regard to the requirements in paragraphs 3(1)(b) and 4(1)(b) and Schedule 1 of the HPR to provide the initial supplier identifier (the name, address and telephone number of either the Canadian manufacturer or the Canadian importer), the name, address and telephone number of a "foreign-based importer" or "non-resident importer" cannot be used.

"LC₅₀": The acronym LC stands for the term "Lethal Concentration". The number 50 in the subscript of LC₅₀ means that, in an animal study, 50% of the exposed animal population died, or was expected to have died, at the specified concentration. The LC₅₀ is one way of measuring the short-term poisoning potential (acute toxicity) of a mixture or substance.

LC₅₀ is used in Subpart 1 of Part 8 of the HPR (Acute Toxicity). LC₅₀ values are used for classification in the acute toxicity hazard class with respect to the inhalation route of exposure. There are three sets of LC₅₀ classification criteria, which deal separately with gases, vapours, and collectively, dusts and mists. The LC₅₀ value is expressed as weight of test substance per standard volume of air (mg/l) for vapours and for dusts and mists, or as volume parts per million (ppmV) for gases.

The LC₅₀ classification criteria in Table 3 to subsection 8.1.1(3) of the HPR are based on an exposure duration of 4 hours (note (c) to Table 3.1.1, GHS seventh revised edition and subsection 8.1.1(4) of the HPR). Where LC₅₀ values have been obtained in studies using an exposure duration of 1 hour, these values must be converted to 4-hour equivalents using the calculation method set out in subsection 8.1.1(4) of the HPR. The calculation presented in subsection 8.1.1(4) of the HPR can only be used to convert an exposure duration of 1 hour to a 4-hour equivalent. Where LC₅₀ values have been obtained in studies using an exposure duration other than 4 hours or 1 hour, these values can be converted to 4-hour equivalents using the formulae found in the Acute Toxicity chapter of the guidance (discussion of subsection 8.1.1(4) of the HPR).

Further information is provided in the guidance chapter corresponding to Subpart 1 of Part 8 (Acute Toxicity).

"LD₅₀": The acronym LD stands for the term "Lethal Dose". The number 50 in the subscript of LD₅₀ means that, in an animal study, 50% of the tested animal population died, or was expected to have died, at the specified dose administered. LD₅₀ values are expressed in terms of the amount of a mixture or substance administered per unit weight of test animal (mg/kg of body weight). The LD₅₀ is one way of measuring the short-term poisoning potential (acute toxicity) of a mixture or substance.

LD₅₀s and LC₅₀s can be found from a variety of sources, including:

• databases such as
  • the Registry of Toxic Effects of Chemical Substances (RTECS^®), CHEMINFO and the Hazardous Substances Data Bank (HSDB^®) in the Canadian Centre for Occupational Health and Safety (CCOHS) CHEMpendium™ collection
• in chemical reviews such as the
  • Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological Profiles
  • World Health Organization (WHO) Environmental Health Criteria (EHC) series
  • International Program on Chemical Safety (IPCS) Concise International Chemical Assessment Documents (CICADs)
  • OECD Screening Information DataSet (SIDS)
• and in the published scientific literature

"Liquid": the criteria for a liquid are outlined in the definition of "liquid" in subsection 1(1) of the HPR. Hazard definitions and classification criteria in the physical and health hazard classes frequently refer to a physical state, either solid, liquid or gas. This definition of "liquid" allows the supplier to determine if their product is a "liquid" within the meaning of the HPR, whenever this term is used.

In some cases, for example, viscous mixtures or substances, a specific melting point cannot be determined. Such a mixture or substance must be regarded as a "liquid" if it meets the criteria set out in (a) and (b) of the definition, and either of the following:

1. the result of the ASTM D 4359-90 test (Standard Test Method for Determining Whether a Material Is a Liquid or a Solid) indicates that the material is a liquid
2. the result of the test for determining fluidity (penetrometer test), prescribed in Section 2.3.4 of Annex A of the European Agreement Concerning the International Carriage of Dangerous Goods by Road, indicates that the mixture or substance is "not pasty"

The test for determining fluidity (penetrometer test) measures the rate of penetration of a mixture or substance using a penetrometer. This test does not actually determine whether the mixture or substance is a liquid. Rather, it determines whether the mixture or substance is "pasty". If a mixture or substance is not "pasty", according to this test method, and if it meets the criteria set out in (a) and (b) of the definition, then it is a "liquid" within the meaning of the HPR.

If a mixture or substance is not a "liquid" as per this definition, then the definitions of "gas" and "solid" should be reviewed to determine the physical state of the mixture or substance for HPR classification purposes. In the definitions and classification criteria for the hazard classes set out in Parts 7 and 8, where no mention is made with regard to physical state, it must be understood that the hazard class applies to all physical states.

The "Manual of Tests and Criteria" is a manual that contains criteria, test methods and procedures to be used for the classification of dangerous goods according to the provisions of Parts 2 and 3 of the United Nations Recommendations on the Transport of Dangerous Goods, Model Regulations, as well as the classification of chemicals presenting physical hazards according to the GHS. Test procedures found in the Manual of Tests and Criteria are referred to in the following physical hazard classes in Part 7 of the HPR:

• Subpart 3: Aerosols
• Subpart 7: Flammable Solids
• Subpart 8: Self-reactive Substances and Mixtures
• Subpart 9: Pyrophoric Liquids
• Subpart 10: Pyrophoric Solids
• Subpart 11: Self-heating Substances and Mixtures
• Subpart 12: Substances and Mixtures Which in Contact with Water, Emit Flammable Gases
• Subpart 13: Oxidizing Liquids
• Subpart 14: Oxidizing Solids
• Subpart 15: Organic Peroxides
• Subpart 16: Corrosive to Metals

The term "as packaged" is used in Subparts 8 and 15 of Part 7 (Self-reactive Substances and Mixtures and Organic Peroxides, respectively), and is defined in sections 7.8 and 7.15 of the HPR to mean "packaged in the form and condition described in test Series B, D, G, and H of Part II of the Manual of Tests and Criteria".

A "manufacturer" is different from an importer. An importer is a supplier who brings a hazardous product into Canada. If an importer modifies a hazardous product that they imported (for example, by repackaging or relabeling it), and subsequently sells the modified hazardous product, then the importer meets the definition of a "manufacturer" under the HPR.

A manufacturer is also different from a distributor. A distributor is a Canadian supplier to whom a hazardous product was sold, who resells the hazardous product without modifying it in any way. If a distributor does modify a hazardous product that they purchased (for example, by repackaging or relabeling it) and subsequently sells it, then the distributor meets the definition of a "manufacturer" under the HPR.

The term "supplier" is defined, in section 2 of the HPA, as "a person who, in the course of business, sells or imports a hazardous product". Therefore, all of the above-mentioned parties (that is, a manufacturer, an importer or a distributor of a hazardous product) are considered as "suppliers" under the HPA.

"OECD" is used in Subparts 2 and 3 of Part 8 (Skin Corrosion/Irritation and Serious Eye Damage/Eye Irritation) to refer to the OECD Guideline for the Testing of Chemicals, No. 404 (Acute Dermal Irritation/Corrosion) and No. 405 (Acute Eye Irritation/Corrosion).

"Outer container" means the outward container of a hazardous product if that product is packaged in more than 1 container. At least 1 container must be physically inside another container to have an outer container. For example, a box in which there are several bottles of a hazardous product is an outer container. Another example would be a hazardous product that is packaged in a bottle that, in turn, is packaged in a set of 2 nested boxes. In this example, only the outward box is considered as an "outer container".

A "pictogram" is composed of a symbol against a background within a border. It is intended to convey specific information about the hazard of a product. Except for the pictogram required for biohazardous infectious materials, the format of the HPR pictograms consists of a black symbol against a white background within a red border in the shape of a square set on 1 point. The Biohazardous Infectious Materials hazard class uses a different pictogram border, as this hazard class is unique to Canada and is not part of the GHS. The Biohazardous Infectious Materials pictogram consists of a black biohazard symbol against a white background within a round black border.

In accordance with section 3.1 of the HPR, any pictogram required to appear on a label must be, with the exception of the size, an exact reproduction of that pictogram as set out in column 3 of Schedule 3 of the HPR. An exact reproduction of the pictogram also means that the proportion of the frame versus the symbol must be in accordance with the pictogram in Schedule 3.

For the hazard classes that were adopted from the GHS, prescribed precautionary statements are found in section 3 of Annex 3 of the GHS. There are 4 types of precautionary statements that cover the following:

• prevention
• response (to accidental spillage or exposure)
• storage
• disposal precautions

Specific precautionary statements have been assigned to each hazard class, category and subcategory. For example, for the Flammable Liquids hazard class, Categories 1, 2, 3, and 4, one of the required prevention precautionary statements is "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking". For a hazardous product that is classified in 1 or more of the hazard classes adopted from the GHS, the prescribed precautionary statements must be provided on the label and SDS, unless either of the following applies:

• a precautionary statement does not apply in a particular case with regard to the normal conditions of use, handling and storage of the hazardous product (subsections 3.2(2) and 4.6(2) of the HPR)
• an exemption under Part 5 of the HPR applies

The following HPR hazard classes are not covered by the GHS:

• Combustible Dusts
• Simple Asphyxiants
• PHNOC
• HHNOC
• Biohazardous Infectious Materials

There are no prescribed precautionary statements for these hazard classes. For a hazardous product that is classified in 1 or more of these hazard classes, the supplier must provide applicable precautionary statements on the label and SDS, unless an exemption under Part 5 of the HPR applies. In addition to the 4 types of precautionary statements required for the hazard classes adopted from the GHS, there is also a requirement to provide "general" precautionary statements, if such statements apply. General precautionary statements in the GHS are found in section 2 of Annex 3 and do not have specific hazard classes or categories assigned. In the seventh revised edition of the GHS, the general precautionary statements provided only apply to consumer products.

The "product identifier" must be the same on both the label and on the SDS for a hazardous product, as required by section 4.2 of the HPR. In the case where the product identifier is the subject of a claim for exemption from the disclosure of confidential business information under the Hazardous Materials Information Review Act, section 5.7 of the HPR specifies that the product identifier must be replaced by a statement that a claim was filed or granted, the date the claim was filed or granted, the registry number assigned to the claim, and coding to replace the product identifier. Again, the same information must be disclosed on both the label and the SDS.

"Risk group classification" refers to the classification of human pathogens in accordance with the Human Pathogens and Toxins Act. Pathogens are ranked in terms of level of hazard: a Risk Group 2 is for less hazardous human pathogens, for example, E. coli and the most hazardous are classified in Risk Group 4, for example, Ebola virus.

"SADT" or "Self-accelerating decomposition temperature" is the lowest temperature at which the rate of decomposition is sufficient to generate heat at a faster rate than the heat can be dissipated to the environment. Temperature is the main factor in determining the decomposition rate, although the size of the package is also important since its dimensions will determine the ability to dissipate heat to the environment.

The SADT is a parameter used in Subparts 8 and 15 of Part 7 (Self-reactive Substances and Mixtures and Organic Peroxides, respectively) for classification purposes.

"Scientifically validated method" refers to the process that has been established for a particular purpose where the accuracy, reliability, and reproducibility of the process are proven using established scientific principles. As specified in sections 2.1 and 2.2 of the HPR, any test using a scientifically validated method that determines the hazardous properties of a product can be used for purposes of classification of the product under the HPR.

"Signal word" indicates the severity of a hazard with either the word "Danger" or "Warning".

Signal words are assigned to a category or subcategory of a hazard class. For the hazard classes adopted from the GHS, the signal words are assigned by section 3 of Annex 3 of the GHS.

The signal words for the hazard classes that are not covered by the GHS (Combustible Dusts, Simple Asphyxiants, PHNOC, Biohazardous Infectious Materials and HHNOC) are assigned in column 4 of Parts 1 to 6 of Schedule 5 of the HPR.

The signal word "Danger" is used for more severe hazards and "Warning" is used for less severe hazards. For example, a product classified in "Reproductive Toxicity — Category 1A or 1B" will require "Danger" as the signal word, whereas a product classified in "Reproductive Toxicity — Category 2" will require "Warning" as the signal word. Some hazard classes or categories do not require the use of a signal word. For example, no signal word is required for a product classified in the "Effects on or via lactation" category of the Reproductive Toxicity hazard class.

For a hazardous product classified in more than 1 category or sub-category of a hazard class or in more than 1 hazard class, the same signal word, "Danger" or "Warning", is not required to be repeated. It only needs to appear once on the label and once on the SDS. Furthermore, as permitted by subsections 3.6(1) and 4.7(1) of the HPR, if there is a requirement to provide both signal words "Danger" and "Warning", then the signal word "Warning" may be omitted.

"Solid": the criteria for a solid are outlined in the definition of "solid" in subsection 1(1) of the HPR. This definition does not define a solid per se. Instead, it specifies that a solid is a mixture or a substance that is not a liquid or gas, which are 2 terms that are also defined in subsection 1(1) of the HPR. Hazard definitions and classification criteria in the physical and health hazard classes frequently refer to a physical state, either solid, liquid or gas. This definition of "solid" will allow the supplier to determine if their product is a "solid" within the meaning of the HPR, whenever this term is used. In the definitions and classification criteria for the hazard classes, set out in Parts 7 and 8, where no mention is made with regard to physical state, it must be understood that the hazard class applies to all physical states.

"United Nations Model Regulations" are referred to in the context of the defined term "UN number" in subsection 1(1) of the HPR (discussed below) and in relation to transportation information (item 14 of Schedule 1 of the HPR).

"UN number" is a 4-digit identification number for a substance, mixture, or group of chemical products identified by the UN Model Regulations and is referred to in Schedule 4 and paragraph 14(a) of Schedule 1 of the HPR. Some hazardous substances have their own UN number (for example, acrylamide has UN2074), whereas sometimes groups of chemicals or products with similar properties receive a common UN number (for example, flammable liquids, not otherwise specified, have UN1993). A chemical in its solid state may receive a different UN number than the same chemical in its liquid phase if the hazardous properties differ significantly. Substances with different levels of purity (or concentration in solution) may also receive different UN numbers.

"Vapour" is used in Subpart 1 of Part 8 (Acute Toxicity) in relation to inhalation exposure. This term is also used in paragraph 9(o) (vapour pressure) and 9(q) (relative vapour density) of Schedule 1.

"Work place" is a place where a person works for remuneration. A supplier is required to comply with the requirements of the HPA and the HPR if the supplier imports or sells a hazardous product intended for use, handling or storage in a workplace in Canada.

Discussion of subsection 1(2) of the Hazardous Products Regulations

The list of hazard classes in Schedule 2 of the HPA is the following:

Physical hazard classes

• Explosives^{Footnote a}
• Flammable gases
• Aerosols
• Oxidizing gases
• Gases under pressure
• Flammable liquids
• Flammable solids
• Self-reactive substances and mixtures
• Pyrophoric liquids
• Pyrophoric solids
• Self-heating substances and mixtures
• Substances and mixtures which, in contact with water, emit flammable gases
• Oxidizing liquids
• Oxidizing solids
• Organic peroxides
• Corrosive to metals
• Combustible dusts^{Footnote b}
• Simple asphyxiants^{Footnote b}
• Repealed^{Footnote c}
• Physical hazards not otherwise classified^{Footnote b}
• Chemicals under pressure^{Footnote d}

Health hazard classes

• Acute toxicity
• Skin corrosion/irritation
• Serious eye damage/eye irritation
• Respiratory or skin sensitization
• Germ cell mutagenicity
• Carcinogenicity
• Reproductive toxicity
• Specific target organ toxicity – single exposure
• Specific target organ toxicity – repeated exposure
• Aspiration hazard
• Biohazardous infectious materials^{Footnote b}
• Health hazards not otherwise classified^{Footnote b}

Discussion of subsection 1(3) of the Hazardous Products Regulations

The term "health professionals" is used in subparagraph 5.7(11)(b)(ii) and in subsections 6(1) and (2) of the HPR. Health professionals (physicians and nurses) are allowed, under specific circumstances, to have access to information on hazardous products for the purpose of making a medical diagnosis of, or rendering medical treatment to, an individual in an emergency. As required by subsection 6(2) of the HPR, such information must be kept confidential by the health professional, except for the purpose for which it was provided, if the supplier has informed the health professional that the information is to be kept confidential.

Discussion of subsection 1(4) of the Hazardous Products Regulations

Some provisions of the HPR, including classification criteria for certain hazard classes, refer to documents such as the GHS, the Manual of Tests and Criteria, the OECD Guideline for the Testing of Chemicals, No. 404 and No. 405, etc. If the text that is referenced or incorporated in the HPR in this manner uses the word "should", this word must be understood to mean the imperative, unless the context requires otherwise.

For example, Item 2(a)(iii) in the table to subsection 7.3.1(2) of the HPR (Aerosols — Classification in a Category of the Class), the criteria for Aerosols — Category 2 include an aerosol dispenser that generates a time equivalent ≤ 300 s/m³, based on test results from the enclosed space ignition test performed in accordance with subsection 31.5 of Part III of the Manual of Tests and Criteria. Subsection 31.5 of Part III of the Manual of Tests and Criteria describes the procedure for the enclosed space ignition test. Paragraph 31.5.2.2.1(a) of the Manual states that "A closure system consisting of a hinged cover should be matched to the open end of the receptacle". This text would be interpreted to mean that, in the event that the enclosed space ignition test is carried out using a closure system consisting of a hinged cover, it must be matched to the open end of the receptacle.

References for this section of the guidance (Hazardous Products Regulations: Part 1 Interpretation)

• 29 CFR 1910.1200, Hazard Communication
• Hazardous Products Act, R.S.C., 1985, c.H-3
• Hazardous Products Regulations, SOR/2015-17
• United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Seventh revised edition, 2017.
• United Nations Manual of Tests and Criteria, Seventh Revised Edition, 2019.

Part 2 Classification of a product, mixture, material or substance

General

This chapter provides guidance to assist suppliers in determining the appropriate hazard classification of a product, mixture, material or substance (PMMS) in relation to the hazard classes, categories and subcategories set out in the Hazardous Products Regulations (HPR). Hazard classification is the process of evaluating all of the available data, in accordance with established scientific principles, to determine whether a PMMS is a "hazardous product" within the definition set out in section 2 of the Hazardous Products Act (HPA). When the evaluation is complete, the PMMS is classified, if applicable, in 1 or more hazard classes and categories or subcategories, depending on the nature and severity of the hazard(s) posed by the PMMS.

Part 2 of the HPR provides a general overview of the procedures to be followed in the hazard classification process. It specifies the types of data that must be considered and sets out principles that are relevant to the classification of a PMMS in the physical and health hazard classes. It also describes principles that apply specifically to the classification of mixtures in the health hazard classes. The sequence of this chapter follows the order of provisions found in Part 2 of the HPR.

The definitions and classification criteria that are relevant to each hazard class are found in the respective Subpart of Part 7 or 8 of the HPR. In addition, the step-wise procedures to be followed for the classification of a mixture, material or substance in each health hazard class are found in Part 8 of the HPR. These step-wise procedures are discussed further in Part 7 and Part 8 of this guidance.

Under the HPA, it is the responsibility of the Canadian supplier to identify whether the products they are selling in or importing into Canada, that are intended for use, handling or storage in a work place in Canada, are "hazardous products". The classification of a hazardous product must be accurate, based on all available data. In addition, it is the duty of the supplier to ensure that labels and safety data sheets of hazardous products sold in or imported into Canada for use, handling or storage in a Canadian work place, comply with all the requirements of the HPA and HPR. Distributors who purchase hazardous products that are intended for use, handling or storage in a work place from other Canadian suppliers and sell these hazardous products meet the definition of a "supplier" under the HPA. Therefore, distributors are also required to ensure that the labels and safety data sheets for the hazardous products they are selling are compliant with the HPA and HPR.

Health Canada has produced several Hazardous Substance Assessments which are technical documents that describe the classification of chemicals in relation to the hazard classes, categories and subcategories set out in the HPR, as educational and informational resources. However, suppliers are ultimately responsible for the accuracy of their hazardous product label and safety data sheet and for ensuring that their hazardous product label and safety data sheet are in compliance with the requirements of the HPA and HPR.

The following definitions from the HPA apply to Part 2 of this guidance:

The HPR is a hazard based regulation. "Hazard" is defined in the dictionary (Merriam-Webster, tenth edition) as the ability to cause harm; a source of danger. It is an intrinsic property due to the nature of the product. For the purpose of these regulations, a PMMS becomes a "hazardous product", within the meaning of the HPA, when it meets the criteria to be classified in at least 1 category or subcategory of any of the physical or health hazard classes of the HPR (Part 7 or Part 8).

For example, sodium hydroxide is a hazardous substance by virtue of its chemical nature. Any change to its chemical nature that results in a substance or mixture other than sodium hydroxide being formed, would result in hazards based on the newly formed substance or mixture. For example, if sodium hydroxide is mixed with an acid resulting in a salt being formed, the hazard assessment is based on the salt which could pose different hazards than those posed by sodium hydroxide or by the acid.

The respective Subpart of Part 7 or 8 of the HPR for each hazard class provides both a definition for the hazard class and classification criteria for each category or subcategory of that hazard class. In terms of scope, for most of the physical and health hazard classes in the HPR, the definition is broader than the criteria. If a PMMS does not meet the definition for a hazard class, it will not meet any of the classification criteria for that hazard class. On the other hand, a PMMS may meet the definition for a hazard class but not its criteria. For a PMMS to be classified in a hazard category or subcategory of a hazard class, it must meet both the definition of the hazard class and the criteria of 1 or more categories or subcategories of the hazard class.

Discussion of subsection 2(1) of the Hazardous Products Regulations

The HPR includes 2 hazard groups: physical hazards (Part 7) and health hazards (Part 8). Each group is divided into hazard classes as found in Subparts 1 to 21 of Part 7 and Subparts 1 to 12 of Part 8. Each Subpart includes 1 or more tables that set out the different classifications possible within the respective hazard class. These are called "classification tables". These tables list the categories and subcategories within the hazard class and the criteria that determine classification within these categories and subcategories.

In most cases, within a single classification table, the order in which the categories and subcategories are laid out is in decreasing order of severity. Thus a PMMS classified in Category 1 is considered more hazardous than a PMMS classified in Category 2 in the same table. For example, a substance that is classified in Flammable Liquids — Category 1 is more hazardous than a substance that is classified in Flammable Liquids — Category 2. This ranking of severity is important for the precedence of classification provisions (subsections 2(2) and (2.1) of the HPR) and the bridging principles provisions (subsections 2.3(1) to (8) of the HPR). The precedence of classification provisions refer to "the most severe hazard", "more severe hazard", and "less severe hazard". The Dilution bridging principle (subsection 2.3(3) of the HPR) refers to "equivalent or less severe hazard classification".

An exception to this rule is found in Subpart 5 of Part 7 of the HPR (Gases under Pressure). The categories listed in the table to section 7.5.1 are not in order of decreasing severity; they just represent different types of compressed gases.

Discussion of subsections 2(2) and 2(2.1) of the Hazardous Products Regulations

Subsections 2(2) and 2(2.1) of the HPR describe the order for evaluating a PMMS in accordance with the criteria of each classification table of each hazard class. This order applies to all hazard classes except for Subpart 5 of Part 7 (Gases Under Pressure) and Subpart 8 of Part 8 (Specific Target Organ Toxicity — Single Exposure (STOT-SE)) of the HPR. For each hazard class, with the exception of Subpart 5 of Part 7 (Gases Under Pressure), the categories and subcategories presented in each classification table are presented in order of the hazard's decreasing severity (see discussion of subsection 2(1) of the HPR). When evaluating a PMMS with regard to a particular hazard class, the classifier must refer to each classification table found within that hazard class and start at the top of each table. If the classifier reaches a category or subcategory for which the PMMS meets the criteria, the PMMS must be classified in that category or subcategory. If a PMMS meets the criteria for more than 1 category or subcategory of the same classification table, then it must be classified, among these categories or subcategories, in the one that represents the most severe hazard.

As specified in subsection 2(2.1) of the HPR, if a PMMS meets the criteria for a more severe hazard category of a hazard class (for example, Category 1 for most hazard classes), it must be classified in that category and does not need to be further evaluated against the criteria for another less severe hazard category (for example, Category 2) within the same classification table of the same hazard class.

As mentioned in the discussion of subsection 2(1) of the HPR, in Subpart 5 of Part 7 of the HPR (Gases Under Pressure hazard class), the categories described in the classification table are not listed in order of decreasing severity. Therefore, it is necessary to evaluate a gas under pressure in relation to all of the criteria in the table to section 7.5.1 to determine in which category the gas must be classified.

The hazard class set out in Subpart 8 of Part 8 of the HPR (Specific Target Organ Toxicity – Single Exposure (STOT-SE)) does not follow the rules described in subsections 2(2) and 2(2.1) of the HPR. In this hazard class, there is 1 classification table that sets out criteria for Category 1, Category 2, and Category 3. Categories 1 and 2 relate to toxicity in a specific target organ that arises from a single exposure and Category 1 represents a more severe hazard than Category 2. Category 3, which relates to transient narcotic effects and/or transient respiratory tract irritation that arise from a single exposure, represents a less severe hazard than Category 2.

However, as specified in subsections 8.8.1(1) and (2) of the HPR, for the purposes of classification in the STOT-SE hazard class, a substance or mixture must be evaluated against the criteria for all three categories. Using the results of this evaluation, the supplier must then follow the criteria in the table to subsection 8.8.1(2) to determine the classification. It is, therefore, possible to have a substance or mixture that is classified in:

• STOT-SE — Category 1
• STOT-SE — Category 2
• STOT-SE — Category 3
• STOT-SE — Category 1 and Category 3 or
• STOT-SE — Category 2 and Category 3

Hazard classes with more than one classification table

There are 4 hazard classes, set out in Subpart 2 of Part 7 (Flammable Gases) and Subparts 1, 4, and 7 of Part 8 (Acute Toxicity, Respiratory or Skin Sensitization and Reproductive Toxicity, respectively) of the HPR that each contain more than 1 classification table. In these hazard classes, the principles described in subsections 2(2) and 2(2.1) of the HPR do not apply from one classification table to another, but only within a classification table. For example, the Reproductive Toxicity hazard class (Subpart 7 of Part 8) has one classification table for Category 1 (further sub-classification in Category 1A or 1B is possible) and Category 2, and a second classification table for Effects on or via Lactation. The 2 tables represent different effects within the hazard class of Reproductive Toxicity and a substance or mixture must be evaluated against the criteria in both tables. As a result, it is possible to have a substance or mixture that is classified in:

• Reproductive Toxicity — Category 1, 1A or 1B
• Reproductive Toxicity — Category 2
• Reproductive Toxicity — Effects on or via Lactation
• Reproductive Toxicity — Category 1, 1A or 1B and Effects on or via Lactation or
• Reproductive Toxicity — Category 2 and Effects on or via Lactation

Discussion of subsection 2(3) of the Hazardous Products Regulations

The prescribed classifications found in Schedule 4 of the HPR maintain the level of protection that was provided by the previous regulations (the repealed Controlled Products Regulations). The listing of a PMMS in Schedule 4 does not constitute a complete classification of that PMMS. If the classification of a PMMS is prescribed in Schedule 4, not only is the PMMS classified in the specified hazard class and hazard category as indicated in Schedule 4, but it must also be further evaluated against the criteria of all other applicable hazard classes. The procedures required to determine the further classification are set out in sections 2.1 (for a material or substance), 2.2 (for a mixture) and 2.7 (for a product) of the HPR.

For example: 2-Bromo-2-nitropropane-1,3-diol (UN number 3241; item 24 of Schedule 4) has a prescribed classification of Physical Hazards Not Otherwise Classified — Category 1. This substance must be evaluated against the criteria of all other hazard classes and, as a result, it could potentially be classified in another hazard class and category or subcategory.

It is important to note that, when evaluating a PMMS that is listed in Schedule 4 to determine the appropriate classification of the PMMS in the other hazard classes, subsections 2(4) (Ingredient – more severe hazard) and 2(5) (Prescribed classification – Subpart 1, 4, 7 or 8 of Part 8) of the HPR must be taken into consideration.

Discussion of subsection 2(4) of the Hazardous Products Regulations

If a PMMS is classified in a category or subcategory of a hazard class as a result of being listed in Schedule 4 of the HPR, and it has been combined with another ingredient that is classified in a more severe category or subcategory of the same classification table of the same hazard class, then the mixture must be classified in the category or subcategory that represents the more severe hazard. In this situation, the more severe hazard category or subcategory within a classification table takes precedence, not the classification prescribed by Schedule 4.

Currently, all substances listed in Schedule 4 are prescribed a classification in Category 1 of either the Self-Heating Substances and Mixtures or the Physical Hazards Not Otherwise Classified hazard class (Subparts 11 and 20, respectively, of Part 7 of the HPR). Therefore, subsection 2(4) of the HPR will not be triggered with the current Schedule 4 items. This provision encompasses the eventuality that a PMMS could, in the future, be added to Schedule 4 and prescribed to be classified in a hazard category or subcategory of a hazard class that is not the most severe category or subcategory.

Discussion of subsection 2(5) of the Hazardous Products Regulations

It is important to note that subsection 2(5) of the HPR will not be triggered with the current Schedule 4 items, since there are currently no mixtures, materials or substances that are prescribed to be classified in the Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity or STOT- SE hazard classes (Subparts 1, 4, 7 or 8, respectively, of Part 8 of the HPR). This provision may be triggered in the future following the addition to Schedule 4 of a new mixture, material or substance that would be prescribed to be classified in one of the above-mentioned hazard classes. For these hazard classes, it is possible for a mixture, material or substance to be classified in more than 1 hazard category within the same hazard class. For example, a substance could be classified in both Respiratory Sensitization — Category 1 and Skin Sensitization — Category 1. Therefore, if additions to Schedule 4 are made, in the future, that prescribe the classification of a mixture, material or substance in the Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity or STOT-SE hazard class, the mixture, material or substance must also be evaluated to determine whether it meets the criteria to be classified in another category of the same hazard class. The procedures to determine classification are set out in section 2.1 (for a material or substance) and 2.2 (for a mixture) of the HPR.

For the Acute Toxicity, Respiratory or Skin Sensitization and Reproductive Toxicity hazard classes (Subparts 1, 4 and 7, respectively, of Part 8 of the HPR), the mixture, material or substance would need to be evaluated against the criteria of the categories set out in the other classification tables that are in the same hazard class. For example, if a substance is prescribed by Schedule 4 of the HPR to be classified in Acute Toxicity – Oral — Category 1 (subsection 8.1.1(3) of the HPR, Table 1 - Oral Exposure Route), the substance must still be evaluated against the criteria in the classification table for the Dermal Exposure Route (subsection 8.1.1(3) of the HPR, Table 2) and the criteria in the classification table for the Inhalation Exposure Route (subsection 8.1.1(3) of the HPR, Table 3).

For a mixture, material or substance that is prescribed by Schedule 4 of the HPR to be classified in the STOT-SE hazard class (Subpart 8 of Part 8 of the HPR), the mixture, material or substance would need to be evaluated against the criteria of the other categories in the same classification table of this hazard class (the Table to subsection 8.8.1(1) of the HPR, which sets out criteria in relation to toxic effects on the central nervous system and respiratory tract and other specific target organs). For example, if a substance is prescribed by Schedule 4 of the HPR to be classified in STOT-SE — Category 1, and there are available data demonstrating transient narcotic effects and/or transient respiratory tract irritation, then, in accordance with item 3 of the Table to subsection 8.8.1(1) of the HPR, the substance would also fall within Category 3 of the STOT-SE hazard class.

Discussion of subsection 2(6) of the Hazardous Products Regulations

The term "substance" refers, in principle, to a single entity (for example, toluene, silver nitrate, ammonia). However, the definition of "substance" in section 2 of the HPA considers that a substance may have small amounts of other constituents such as stabilizing additives, impurities and stabilizing solvents. For example, phenol and diacetone alcohol are impurities that can be present in acetone, which is a substance. Impurities, stabilizing solvents, or stabilizing additives may have their own unique hazards and/or may contribute to the hazards of the substance.

For the purposes of hazard classification under the HPR, impurities, stabilizing solvents, or stabilizing additives that are, by themselves, classified in a category or subcategory of a health hazard class and that are present in a substance at a concentration above the corresponding concentration limit must be considered for the classification of the substance. In such a situation, the substance must be classified in accordance with the data pertaining to the impurity, stabilizing solvent, or stabilizing additive, unless there are test data showing that the substance does not present that particular hazard. Impurities, stabilizing solvents, and stabilizing additives that are part of a substance are present during any tests that have been conducted on the substance, and therefore, their hazards would be reflected in the results of these tests.

Discussion of subsection 2(7) of the Hazardous Products Regulations

For the purposes of hazard classification under the HPR, impurities, stabilizing solvents or stabilizing additives in mixtures must be considered in the overall classification of a mixture if they are, by themselves, classified in a category or subcategory of a health hazard class and are present at a concentration above the concentration limit for that category or subcategory of that health hazard class. Thus, for the purposes of hazard classification of a mixture, a supplier must consider impurities, stabilizing solvents, and stabilizing additives that are present in the mixture in the same manner as the supplier would consider the ingredients of the mixture. In the case of Subparts 1 to 10 and 12 of Part 8 of the HPR, subsections 2.5(1) (concentration limits – lower concentration) and 2.5(2) (concentration limits – equivalent or higher concentration) of the HPR must be considered in the assessment of impurities, stabilizing additives, and stabilizing solvents that are part of a mixture.

An example of a stabilizing solvent in a mixture would be toluene or another hydrocarbon in an industrial paint. Without the stabilizing solvent, the resin would dry and not be able to be applied to a substrate.

Discussion of subsection 2(8) of the Hazardous Products Regulations

This provision applies to situations in which 2 or more distinct PMMS are packaged together in an outer container, such as in a kit. In such a situation, for the purposes of classification, the supplier must not consider the assemblage as 1 PMMS. Instead, each PMMS must be assessed individually and each PMMS that meets the criteria to be classified in 1 or more hazard classes must have its own label and safety data sheet.

Notes:

1. "two or more different and individually packaged" PMMS – this means a package containing at least 2 individually packaged different PMMS. It would exclude, for example, 6 bottles of the same PMMS in an outer box. Unless 1 of the exceptions set out in section 5.2 of the HPR applies, where more than 1 container of the same PMMS is packaged in an outer container to form a multipack, the outer container label must provide the same information elements as the label of each container within the multipack.
2. "designed to be accessed individually" – this means that in the normal course of use, each PMMS is accessed on its own. This type of assemblage is commonly referred to as a "kit", but all assemblages that contain different and individually packaged PMMS that can be accessed individually would be captured by subsection 2(8) of the HPR. For example, in the case of a 2-part system (such as 2 containers of different PMMS in 1 outer box) in which each part has to be opened and used in some way, each part must be assessed individually for the purpose of classification.

An assemblage that is designed to have each PMMS accessed individually and in which the PMMS are packaged together in an outer container, as described in this subsection, often comes with instructions for use that require the PMMS to be combined or mixed together. Section 4.1 of the HPR pertains to situations in which a hazardous product comes with instructions for use that require its combination with 1 or more PMMS and this combination results in the creation of 1 or more new materials or substances that present a new or more severe hazard.

For such a hazardous product, additional information with regard to the new or more severe hazard is required on the safety data sheet. Further information, including information regarding hazardous products packaged in multi-compartment containers, can be found in the discussion of subsection 4.1(1) of the HPR.

It is important to note that there is a labelling exemption in section 5.3 of the HPR for the outer container of assemblages that contain at least 2 different hazardous products packaged together. Further information can be found in the discussion of section 5.3 of the HPR.

Discussion of subsection 2(9) of the Hazardous Products Regulations

When reviewing animal data from a particular species of animal (for example, rat) for the purpose of classifying a substance or mixture in any of the health hazard classes referred to in Subparts 1 to 10 and 12 of Part 8 of the HPR (that is, all of the health hazard classes except for Subpart 11 of Part 8 - Biohazardous Infectious Materials (BIM)), if there is conclusive evidence on the mechanism or mode of action of the substance or mixture, this evidence must be considered. Where there is conclusive evidence, based on established scientific principles, that the mechanism or mode of action of the substance or mixture in that particular species of animal is not relevant to humans, the animal data must not be used for the purpose of determining classification. However, if the supplier does not have conclusive evidence that the mechanism or mode of action is not relevant to humans, then the animal data must be considered for the purpose of determining classification. A mechanism or mode of action that is not relevant to humans is one that is not operative in humans.

For example, suppose there are animal data which demonstrate that exposure to a substance results in an increased incidence of kidney tumours in male rats, but there is evidence, based on established scientific principles, that the mechanism of tumour formation involves an enzyme which is specific to the male rat and which is not present in humans. In this situation, the animal data which demonstrate the positive association between exposure to the substance and the development of tumours in male rats must not be used for the purpose of classifying the substance in the Carcinogenicity health hazard class (Subpart 6 of Part 8). Other available data of the types specified in section 2.1 of the HPR would still need to be taken into consideration to determine the classification of the substance in the Carcinogenicity health hazard class.

This provision does not apply to BIM as the scope of the BIM hazard class is not limited to materials that are infectious to humans. It also includes materials that are infectious to animals.

Material or Substance

Discussion of section 2.1 of the Hazardous Products Regulations

When classifying materials or substances with respect to Parts 7 and 8 of the HPR (Physical and Health hazard classes, respectively), certain requirements are to be met, including the types of data to be considered and the order of precedence for considering these different types of data. The types of data that must be used are as specified in subparagraphs 2.1(a)(i) to (iv) and 2.1(b)(i) to (iv) of the HPR, as applicable.

Data on the material or substance itself take precedence over data on a similar material or substance. Data on the material or substance may include any of the following:

• results of testing or studies carried out in accordance with the test methods referred to in Part 7 or 8
• results of testing or studies carried out in accordance with generally accepted standards of good scientific practice at the time the test or study was carried out
• conclusions based on established scientific principles
• case reports or documented observations

If data on the material or substance are unavailable or are insufficient to evaluate the material or substance in accordance with the applicable criteria, then for each hazard class except Skin Corrosion/Irritation and Serious Eye Damage/Eye Irritation (Subparts 2 and 3, respectively, of Part 8), data of the types listed above for a material or substance with similar properties to the material or substance that is being classified must be considered. Subparts 2 and 3 of Part 8 are excluded because these hazard classes provide a sequential approach to the determination of classification that already incorporates the consideration of different types of data, beginning with data on the substance itself and then other types of data, such as pH, followed by data on similar substances.

According to subparagraphs 2.1(a)(iii) and 2.1(b)(iii) of the HPR, conclusions based on established scientific principles are to be considered when classifying a material or substance. This provision permits the consideration of conclusions based on Quantitative Structure Activity Relationships (QSARs) and Structure-Activity Relationships (SARs) to classify a material or substance.

"Documented observations" are meant to encompass a wide range of evidence, including case reports and incident reports (subparagraphs 2.1(a)(iv) and 2.1(b)(iv) of the HPR).

Where impurities, stabilizing additives and stabilizing solvents are part of a material or substance and are, by themselves, classified in a category or subcategory of a health hazard class, they must be taken into consideration for the classification of the material or substance if they are present at a concentration that exceeds the cut-off value or concentration limit for that category or subcategory of that health hazard class (see discussion of subsection 2(6) of the HPR).

Classification is based on existing data and no additional testing is required to be undertaken; however, suppliers are not prevented from performing testing. All available data must be evaluated against the criteria for each hazard class to determine the classification of a material or substance.

When classifying a material or substance, section 2.8 of the HPR (requirement, for certain physical hazard classes, to evaluate solids using data that relate to the physical form in which the solid is sold or imported) and section 2.9 of the HPR (provision relating to biological availability) must be taken into consideration.

Sources of information that may be used in hazard classification include, but are not limited to, the following:

• Fire Protection Guide to Hazardous Materials
• Transport Canada Emergency Response Guidebook, most recent version
• PubChem
• The National Institute for Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards
• International Chemical Safety Cards
• Internationally Peer Reviewed Chemical Safety Information (INCHEM)
• OECD eChemPortal;
• TLVs and BEIs (ACGIH)
• The Merck Index
• Published literature
• CRC Handbook of Chemistry and Physics
• Sax's Dangerous Properties of Industrial Materials, latest edition
• Bretherick's Handbook of Reactive Chemicals Hazards, latest edition
• International Agency for Research on Cancer (IARC) Monographs on the Evaluation of Carcinogenic Risks to Humans
• National Toxicology Program Report on Carcinogens
• Agency for Toxic Substances and Disease Registry (ATSDR) - Toxicological Profiles
• Canadian Centre for Occupational Health and Safety (CCOHS) CHEMINFO database
• Répertoire Toxicologique (REPTOX) – Recherche une substance

Mixtures

Classification

Discussion of subsection 2.2(1) of the Hazardous Products Regulations

This subsection provides rules that apply to the classification of mixtures with respect to the physical hazard classes (Part 7 of the HPR). The available data must be evaluated against the criteria for each category or subcategory of each physical hazard class in order to determine the mixture's classification. Certain rules with respect to the types of data to be considered and the order of precedence for considering these different types of data must be followed. The types of data that must be used are as specified in subparagraphs 2.1(a)(i) to (iv) and 2.1(b)(i) to (iv) of the HPR, as applicable.

Data on the mixture itself take precedence over data on a similar mixture. As for the classification of a material or substance (section 2.1 of the HPR), data on the mixture itself may include any or more than 1 of the following:

• results of testing or studies carried out in accordance with the test methods referred to in Part 7
• results of testing or studies carried out in accordance with generally accepted standards of good scientific practice at the time the test or study was carried out
• conclusions based on established scientific principles
• case reports or documented observations

If data on the mixture itself are unavailable or are insufficient to evaluate the mixture in accordance with the applicable criteria, then data of the types listed in subparagraphs 2.1(b)(i) to (iv) of the HPR for a mixture with similar properties to the mixture that is being classified must be considered.

According to subparagraphs 2.1(a)(iii) and 2.1(b)(iii) of the HPR, conclusions based on established scientific principles are to be considered when classifying a mixture. This provision permits the consideration of conclusions based on QSARs and SARs to classify a mixture.

"Documented observations" are meant to encompass a wide range of evidence, including case reports and incident reports (subparagraphs 2.1(a)(iv) and 2.1(b)(iv) of the HPR).

Classification is based on existing data and no additional testing is required to be undertaken; however, suppliers are not prevented from performing testing. All available data must be evaluated against the criteria for each physical hazard class to determine the physical hazard classification of a mixture.

When classifying mixtures with respect to physical hazards, section 2.8 of the HPR must be taken into consideration (that is the requirement, for certain physical hazard classes, to evaluate solids using data that relate to the physical form in which the solid is sold or imported).

In addition to using information on the mixture itself or information on a mixture with similar properties, there are 4 physical hazard classes which include provisions for classifying mixtures based on information on the ingredients in the mixture.

1. In Subpart 2 of Part 7 of the HPR (Flammable Gases), subsections 7.2.1(3) to 7.2.1(5) allow the use of a calculation method to determine the flammability of a gas mixture. This method uses data on the ingredients to determine the flammability of the gas mixture.
2. In Subpart 6 of Part 7 of the HPR (Flammable Liquids), paragraph 7.6.1(4)(b) also refers to a calculation method which uses data on ingredients to determine the flammability of a liquid mixture.
3. In Subpart 15 of Part 7 of the HPR (Organic Peroxides), subsections 7.15.1(4) and 7.15.1(5) describe procedures to be used for the classification of a mixture of organic peroxides. These provisions do not refer to a calculation method and take into consideration data available on the ingredients of the mixture, as well as data available on the mixture as a whole.
4. In Subpart 4 of Part 7 of the HPR (Oxidizing Gases), section 7.4.1 allows the use of a calculation method to determine whether a gas mixture is an oxidizing gas. This method uses data on the ingredients to determine the oxidizing power of the gas mixture.

Although these 4 subparts include provisions that allow the classification of mixtures based on data available on their respective ingredients, it is important to note that for classification purposes, data on the mixture itself or a mixture with similar properties always take precedence over data on the ingredients.

For example, to determine the flammability of a liquid mixture, if there is no information with respect to the flash point or the initial boiling point on the mixture itself, then data from a similar liquid mixture must be used. If there is also no information on the flash point or the initial boiling point for a similar liquid mixture, noted above, an applicable calculation method may be used to determine the flash point of the liquid mixture, provided that the calculation is applied under conditions for which it has been validated according to generally accepted standards of good scientific practice (paragraph 7.6.1 (4)(b) of the HPR).

Discussion of subsection 2.2(2) of the Hazardous Products Regulations

This subsection provides rules that apply to the classification of mixtures with respect to the health hazard classes (Part 8 of the HPR). When classifying a mixture in a health hazard class, the mixture must be evaluated in accordance with data of the types referred to in subparagraphs 2.1(a)(i) to (iv) of the HPR in relation to the mixture as a whole, a mixture with similar properties, or in relation to the ingredients of the mixture. The classification must follow the order of provisions for the classification of mixtures, as set out in each health hazard class. This procedure will generally (but not always) require the following steps:

1. Where test data are available for the mixture itself, the classification of the mixture will be based on that data.
2. Where test data are not available for the mixture itself, then the applicable bridging principles (see subsections 2.3(3) to (8) of the HPR) must be used. In order to apply the bridging principles, sufficient test data must be available for similar mixtures and for individual ingredients of the mixture to be classified.
3. If test data are not available for the mixture itself, and sufficient data to allow the application of bridging principles are also not available, then the method(s) described in each subpart for determining the hazards based on the ingredients of the mixture must be applied to classify the mixture (for example, application of cut-off values/concentration limits/calculation methods).

According to subparagraph 2.1(a)(iii) of the HPR, conclusions based on established scientific principles are to be considered when classifying a mixture. This provision permits the consideration of conclusions based on QSARs and SARs to classify a mixture.

"Documented observations" are meant to encompass a wide range of evidence, including case reports and incident reports (subparagraph 2.1(a)(iv) of the HPR).

Where impurities, stabilizing additives and stabilizing solvents are part of a mixture and are, by themselves, classified in a category or subcategory of a health hazard class, they must be taken into consideration for the classification of the mixture if they are present at a concentration that exceeds the cut-off value or concentration limit for that category or subcategory of that health hazard class (see discussion of subsection 2(7) of the HPR). Subsections 2.5(1) (concentration limits – lower concentration) and 2.5(2) (concentration limits – equivalent or higher concentration) of the HPR must be considered in the assessment of impurities, stabilizing additives and stabilizing solvents that are part of a mixture.

Classification is based on existing data and no additional testing is required to be undertaken; however, suppliers are not prevented from performing testing. All available data must be evaluated against the criteria for each health hazard class to determine the health hazard classification of a mixture.

It is important to note that section 2.9 of the HPR (biological availability) must be taken into consideration when classifying mixtures with respect to health hazards.

Discussion of subsection 2.2(3) of the Hazardous Products Regulations

Except in the case of Subparts 1, 4, 7 and 8 of Part 8 of the HPR (Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity and STOT-SE, respectively), the first provision that results in a mixture being classified in a category or subcategory of a health hazard class concludes the process of classification with regard to that particular health hazard class. No further evaluation of the mixture in relation to the remaining provisions for the classification of mixtures in that health hazard class is necessary.

Subparts 1, 4, 7 and 8 of Part 8 are different because, for these health hazard classes, it is possible for a mixture to be classified in more than 1 category. As described in the discussion of subsections 2(2) and 2(2.1) of the HPR, these health hazard classes contain more than 1 classification table and it is necessary to evaluate the data for a mixture against the criteria in each classification table. For Subpart 8 of Part 8 (STOT-SE), a supplier must evaluate the data for a mixture against the criteria for all 3 of the categories in the table to subsection 8.8.1(1) of the HPR and then follow the criteria in the table to subsection 8.8.1(2) of the HPR to determine the resulting classification.

It is important to note that the provisions for classifying mixtures must be applied in the order specified in each Subpart of Part 8. This order is very important because classification using data on the mixture as a whole may result in a more severe or less severe hazard classification than would result if the bridging principles or methods for estimating hazards based on the ingredients of the mixture were used. For example, consider the situation where test data for a mixture shows that it meets the criteria for Skin Irritation — Category 2, but does not meet any of the criteria for Skin Corrosion (Category 1A, 1B or 1C). Even if the mixture contains an ingredient that would trigger the classification of the mixture in Skin Corrosion — Category 1C based on the application of cut-off values/concentration limits, the mixture must be classified in Skin Irritation — Category 2 and not in Skin Corrosion — Category 1C, based on the order of the provisions for the classification of mixtures specified in Subpart 2 of Part 8 (Skin Corrosion/Irritation hazard class).

Bridging principles

The "GHS" means the United Nations document entitled Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Seventh Revised Edition.

Bridging principles, which were adopted from the GHS, apply to the classification of mixtures in the health hazard classes set out in Subparts 1 to 10 of Part 8 of the HPR (these health hazard classes are covered in the GHS). Bridging principles do not apply to the classification of mixtures in the Biohazardous Infectious Materials or Health Hazards Not Otherwise Classified hazard classes (Subparts 11 and 12, respectively, of Part 8). These health hazard classes are not from the GHS.

When a mixture has not been tested, the application of bridging principles ensures that the classification process uses the available data to the greatest extent possible in characterizing the potential hazard. When there are sufficient data on both its ingredients and similar tested mixtures, these data can be used in accordance with the following bridging principles, where appropriate and if there is an indication to that effect within the relevant Subpart of Part 8:

• Dilution (subsection 2.3(3) of the HPR)
• Increase in concentration of hazardous ingredient (subsection 2.3(5) of the HPR)
• Interpolation (subsection 2.3(6) of the HPR)
• Substantially similar mixtures (subsection 2.3(7) of the HPR)
• Aerosols – health hazard classes (subsection 2.3(8) of the HPR)

In order to use these 5 bridging principles, the supplier must have test data on another mixture, often referred to in the HPR as the "tested mixture", which must be similar to the mixture that the supplier wants to classify. In the absence of such a "tested mixture", the bridging principles cannot be used. In these instances, it is necessary to refer again to the Subpart of Part 8 that deals with the health hazard class under review, and continue with the next provision in the procedure for the classification of mixtures in that health hazard class.

A sixth bridging principle, that is "Production batches" (subsection 2.3(4) of the HPR), is an exception because it is not necessary to have data on the ingredients of the mixture to apply this bridging principle. As long as batches of a particular mixture are manufactured using the same ingredients and according to the same manufacturing process, the application of this bridging principle to an untested batch requires sufficient data on similar tested batches, but does not require the evaluation of data on the ingredients.

When following the procedure for the classification of a mixture in a health hazard class, at the appropriate step, the provisions in the relevant Subpart of Part 8 will indicate the use of the bridging principles and there will be a reference to some or all of subsections 2.3(3) to (8) of the HPR. The bridging principles are grouped in subsections 2.3(3) to (8) of the HPR instead of being repeated in the Subpart for each health hazard class.

The table in the discussion of subsection 2.3(2) of the HPR shows which bridging principles apply to each health hazard class.

If sufficient data to apply bridging principles are not available, then it is necessary to refer again to the relevant Subpart of Part 8 that deals with the health hazard class under review and continue with the next provision in the procedure for the classification of mixtures in that health hazard class.

Discussion of subsection 2.3(1) of the Hazardous Products Regulations

Regarding the term "production batch", when a mixture is manufactured in batches, usually engineering parameters are put in place to ensure that the variation between batches is limited as much as possible so that every batch produced should essentially be "identical" to all other batches.

"Batch-to-batch variability" refers to situations where products are produced to specified criteria, but product composition varies from batch to batch. Variations in product composition could be due to factors such as production tolerances (fluctuations permitted by the quality control parameters of the manufacturing process) and varying concentrations of starting materials. As a result of these factors, the concentration of a particular hazardous ingredient in a hazardous product may vary from one batch to another. Further guidance regarding batch-to-batch variability and the disclosure of ingredient concentration ranges on safety data sheets is provided in Part 4 of this guidance. The term "batch-to-batch variability" is not used or defined in the HPA or the HPR. This term is used in Part 2 and Part 4 of this guidance.

The term "tested mixture" means that test data are available on the mixture itself. These data could include results of testing or studies, case reports or documented observations, as appropriate.

Discussion of subsection 2.3(2) of the Hazardous Products Regulations

This provision specifies that the bridging principles must not be applied unless indicated in the Subpart of Part 8 of the HPR that deals with the health hazard class under review. For each of the health hazard classes set out in Subparts 1 to 10 of Part 8 of the HPR, the classification procedure for mixtures specifies which bridging principles are applicable for that hazard class. Bridging principles do not apply to the classification of mixtures in Subpart 11 (Biohazardous Infectious Materials) or Subpart 12 (Health Hazards Not Otherwise Classified) of Part 8 of the HPR.

It is important to note that, as shown below in Table 2.1 Summary – Application of the bridging principles to the health hazard classes of the HPR, not all bridging principles are to be used for all health hazard classes. The bridging principle that is appropriate to the mixture being classified depends on the type of data available for that mixture and on the hazard being assessed.

Table 2.1 Summary – Application of the bridging principles to the health hazard classes of the HPR

Health hazard class	Bridging principles
	Dilution	Production Batches	Increase in concentration of hazardous ingredient	Interpolation	Substantially similar mixtures	Aerosols
Acute Toxicity	YesFootnote 1	Yes	Yes	Yes	Yes	Yes
Skin Corrosion / Irritation	YesFootnote 1	Yes	YesFootnote 2	Yes	Yes	Yes
Serious Eye Damage / Eye Irritation	YesFootnote 1	Yes	YesFootnote 3	Yes	Yes	Yes
Respiratory or Skin Sensitization	Yes	Yes	Yes	Yes	Yes	Yes
Germ Cell Mutagenicity	Yes	Yes	No	No	Yes	No
Carcinogenicity	Yes	Yes	No	No	Yes	No
Reproductive Toxicity	Yes	Yes	No	No	Yes	No
Specific Target Organ Toxicity – single exposure	Yes	Yes	Yes	Yes	Yes	Yes
Specific Target Organ Toxicity – repeated exposure	Yes	Yes	Yes	Yes	Yes	Yes
Aspiration Hazard	Yes	Yes	Yes	Yes	Yes	No
Biohazardous Infectious Materials	Bridging principles do not apply to this health hazard class.
Health Hazards Not Otherwise Classified	Bridging principles do not apply to this health hazard class.
1 Special rules apply; please refer to the discussion of paragraph 2.3(3)(a) Return to footnote 1 referrer 2 Special rules apply; please refer to the discussion of paragraph 2.3(5)(b) Return to footnote 2 referrer 3 Special rules apply; please refer to the discussion of paragraph 2.3(5)(c) Return to footnote 3 referrer

Discussion of subsection 2.3(3) of the Hazardous Products Regulations

The "Dilution" bridging principle may be applied, as specified, to the classification of mixtures in all health hazard classes set out in Part 8 of the HPR, except Subparts 11 and 12 (Biohazardous Infectious Materials and Health Hazards Not Otherwise Classified, respectively).

The "Dilution" bridging principle may be applied if a tested mixture is diluted with a diluent that has the same or a less severe classification than the least hazardous ingredient of the tested mixture. The phrase "does not affect the classification of the tested mixture" is included in subsection 2.3(3) of the HPR because there could be situations where the dilution of the tested mixture with a diluent might affect classification. The determination of whether the diluent affects the hazard classification of the tested mixture must be based on established scientific principles.

For 3 of the health hazard classes (Subparts 1, 2, and 3 of Part 8 – Acute Toxicity, Skin Corrosion/Irritation and Serious Eye Damage/Eye Irritation, respectively), a calculation method, as described in section 8.1.5, 8.2.11 or 8.3.11 of the HPR, respectively, can be used to determine the classification of the diluted mixture. The calculation method may result in a less severe hazard classification than if the diluted mixture were to be classified in the same category as the tested mixture.

If the calculation method cannot be or is not used, then the default method of classifying the diluted mixture in the same category as the tested mixture must be used. This conservative approach assumes that the diluent had no impact on the hazards of the mixture. Either the calculation method or the "default" method may be used.

The default method of classifying the diluted mixture in the same category as the tested mixture (as described in paragraph 2.3(3)(b) of the HPR) is the mandatory method used for the health hazard classes other than Acute Toxicity, Skin Corrosion/Irritation and Serious Eye Damage/Eye Irritation. For example: Mixture A, which has been classified in Skin Sensitization — Category 1 based on test data, is diluted with Diluent B to form Mixture C. If Diluent B has an equivalent or lower skin sensitization classification than that of the least hazardous ingredient in Mixture A, that is, the ingredient in Mixture A with the lowest classification for that hazard class, and Diluent B does not affect the hazard classification of Mixture A, then it can be assumed that the respective hazard of the new mixture C is equivalent to that of the original tested mixture. Therefore, Mixture C must also be classified in Skin Sensitization — Category 1.

As another example, Mixture A, which has been classified in STOT- SE — Category 1, is diluted with Diluent B to form Mixture C. Diluent B is not classified in STOT-SE, and the least hazardous ingredient in Mixture A is, by itself, also not classified in STOT-SE. Diluent B does not affect the hazard classification of Mixture A. Thus, it can be assumed that the respective hazard of the new mixture C is equivalent to that of the original tested mixture. Therefore, Mixture C must also be classified in STOT-SE — Category 1.

Discussion of subsection 2.3(4) of the Hazardous Products Regulations

As defined in subsection 2.3(1) of the HPR, the term "production batches" means "a batch that results from a consistent production process using fixed physico-chemical parameters when there is no intention to alter the characteristics of the final product".

The "Production batches" bridging principle may be applied, as specified, to the classification of mixtures in all health hazard classes set out in Part 8 of the HPR, except Subparts 11 and 12 (Biohazardous Infectious Materials and Health Hazards Not Otherwise Classified, respectively). If test data are available for 1 batch of a mixture that is produced under a controlled process, it is assumed that other batches of the same mixture from the same supplier produced under the same conditions have the same properties, and therefore the same classification.

However, if a change occurs during the production process that could influence the toxicity or any other hazard related to the mixture, then the mixture could have a different classification. For example, if temperature controls failed during the production run of a batch, then this batch could have a different classification than that of the other batches. In this situation, it is not possible to apply the "Production batches" bridging principle and it is necessary to refer again to the Subpart of Part 8 that deals with the health hazard class under review, and continue with the next provision in the procedure for the classification of mixtures in that health hazard class.

Discussion of paragraph 2.3(5)(a) of the Hazardous Products Regulations

The "Increase in concentration of hazardous ingredient" bridging principle may be applied, as specified, to the classification of mixtures in the health hazard classes set out in Subparts 1, 4 and 8 to 10 of Part 8 of the HPR (Acute Toxicity, Respiratory or Skin Sensitization, STOT-SE, Specific Target Organ Toxicity – Repeated Exposure (STOT-RE) and Aspiration Hazard, respectively). This bridging principle does not apply to Subparts 5, 6, 7, 11 or 12 of Part 8 of the HPR (Germ Cell Mutagenicity, Carcinogenicity, Reproductive Toxicity, Biohazardous Infectious Materials or Health Hazards Not Otherwise Classified, respectively).

This provision considers that if a mixture is already classified in the most severe hazard category (that is, Category 1) of one of the above-mentioned hazard classes, increasing the concentration of a hazardous ingredient in the mixture will not affect this classification, because the classification cannot be more severe than it already is. Therefore, the untested mixture would also be classified in Category 1 without additional testing. In this provision, "increased concentration" means the increased concentration of ingredient(s) in the mixture that is/are classified in the same hazard class in which the Category 1 ingredient is classified. For example, if a mixture is classified in STOT-RE — Category 1, and the supplier increases the concentration of any ingredient in the mixture that is classified in any category of STOT-RE, then the new mixture would remain classified in STOT–RE — Category 1.

This bridging principle only applies within a hazard class; it does not apply across hazard classes.

Discussion of paragraph 2.3(5)(b) of the Hazardous Products Regulations

A different provision for the "Increase in concentration of hazardous ingredient" bridging principle is provided for Subpart 2 of Part 8 of the HPR (Skin Corrosion/ Irritation) because corrosion and irritation hazards are considered distinct from each other. For example, increasing the concentration of a skin irritant still results in a mixture that produces skin irritation, not skin corrosion.

The term "increased concentration" should be understood as the increased concentration of an ingredient in the mixture that is classified in this hazard class (that is, Category 1, 1A, 1B, or 1C skin corrosive or Category 2 skin irritant).

Where sufficient data are available, substances and mixtures which cause skin corrosion can be further sub-classified into Category 1A, 1B, or 1C. To apply the bridging principle described in subparagraph 2.3(5)(b)(i) of the HPR, the tested mixture must be classified in Skin Corrosion — Category 1A. For a tested mixture that is already classified in Category 1A, an increase in the concentration of an ingredient classified in Category 1, 1A, 1B or 1C of this hazard class requires the new mixture to remain classified in 1A. For a tested mixture that is already classified in Category 1A, an increase in the concentration of an ingredient classified in Category 2 of this hazard class requires the new mixture to remain classified in 1A, as long as the increase in the concentration of the Category 2 ingredient does not result in a decrease in the concentration of any ingredient classified in Category 1, 1A, 1B or 1C of this hazard class.

This subparagraph cannot be applied to a tested mixture classified in Category 1B or Category 1C.

Category 1 of the Skin Corrosion/Irritation hazard class addresses substances and mixtures which cause skin corrosion. For example, consider a mixture that is classified in Skin Corrosion — Category 1 (without further sub-classification). If the concentration of the Category 1 skin corrosive ingredient is increased, then, although this is not specified in the Regulations, the resultant mixture could also be classified in Category 1 (without further sub-classification).

This bridging principle can also be applied to mixtures classified in Skin Irritation — Category 2 (subparagraph 2.3(5)(b)(ii) of the HPR). The mixture being classified must not contain any Category 1 ingredients. If a tested mixture is classified in Skin Irritation — Category 2 and there is an increase in the concentration of a Skin Irritation — Category 2 hazardous ingredient, the resultant mixture must also be classified in Skin Irritation — Category 2.

Discussion of paragraph 2.3(5)(c) of the Hazardous Products Regulations

This provision for the "Increase in concentration of hazardous ingredient" bridging principle applies to mixtures classified in the Serious Eye Damage/Eye Irritation hazard class (Subpart 3 of Part 8 of the HPR).

The term "increased concentration" should be understood as the increased concentration of an ingredient in the mixture that is classified in this hazard class (that is, Serious Eye Damage — Category 1 or Eye Irritation — Category 2, 2A or 2B).

To apply the bridging principle described in subparagraph 2.3(5)(c)(i) of the HPR, the tested mixture must be classified in Serious Eye Damage — Category 1. For a tested mixture that is already classified in Category 1, an increase in the concentration of an ingredient classified in Category 1 of this hazard class requires the new mixture to remain classified in Category 1. For a tested mixture that is already classified in Category 1, an increase in the concentration of an ingredient classified in Category 2, 2A or 2B of this hazard class requires the new mixture to remain classified in Category 1, as long as the increase in the concentration of the ingredient classified in Category 2, 2A or 2B does not result in a decrease in the concentration of any ingredient classified in Category 1 of this hazard class.

This bridging principle can also be applied to mixtures classified in Eye Irritation — Category 2A of the Serious Eye Damage/Eye Irritation hazard class (subparagraph 2.3(5)(c)(ii) of the HPR). The mixture being classified must not contain any Category 1 ingredients. If a tested mixture is classified in Eye Irritation — Category 2A and there is an increase in the concentration of an Eye Irritation — Category 2A or 2B hazardous ingredient, the resultant mixture must be classified in Eye Irritation — Category 2A.

Subparagraph 2.3(5)(c)(ii) of the HPR cannot be applied to a tested mixture classified in Eye Irritation – Category 2B.

In addition, consider a tested mixture that is classified in Eye Irritation — Category 2 (without further sub-classification) and which does not contain any Category 1 ingredients. If there is an increase in the concentration of an Eye Irritation — Category 2 hazardous ingredient, then, although this is not specified in the Regulations, the resultant mixture could also be classified in Eye Irritation — Category 2 (without further sub-classification).

Discussion of subsection 2.3(6) of the Hazardous Products Regulations

The "Interpolation" bridging principle may be applied, as specified, to the classification of mixtures in the health hazard classes set out in Subparts 1 to 4 and 8 to 10 of Part 8 of the HPR (Acute Toxicity, Skin Corrosion/Irritation, Serious Eye Damage/Eye Irritation, Respiratory or Skin Sensitization, STOT-SE, STOT-RE, and Aspiration Hazard, respectively). This bridging principle does not apply to Subparts 5, 6, 7, 11 or 12 of Part 8 of the HPR (Germ Cell Mutagenicity, Carcinogenicity, Reproductive Toxicity, Biohazardous Infectious Materials or Health Hazards Not Otherwise Classified, respectively).

To use interpolation, there must be 3 mixtures (A, B and C) with identical ingredients, of which mixtures A and B have been tested and are classified in the same hazard category of the same hazard class. Untested mixture C has the same hazardous ingredients as mixtures A and B but with concentrations intermediate to (that is, in between) the concentrations found in mixtures A and B. In this case, mixture C must also be classified in the same hazard category of the same hazard class as mixtures A and B.

For example:

Table 2.2 Hypothetical concentrations of Ingredients X, Y, and Z present in Mixtures A, B, and C where untested Mixture C contains concentrations intermediate to the concentrations found in Mixtures A and B

	Mixture A (tested) Classification: STOT-RE — Category 2	Mixture B (tested) Classification: STOT-RE — Category 2	Mixture C (untested)
Ingredient X (non-hazardous)	80%	65%	72%
Ingredient Y (hazardous)	15%	25%	20%
Ingredient Z (hazardous)	5%	10%	8%

Based on the above data, and using the bridging principle set out in subsection 2.3(6) of the HPR, mixture C must also be classified in STOT-RE — Category 2 because the concentration of each hazardous ingredient in mixture C falls between the concentrations of the same hazardous ingredient in mixtures A and B.

It is important to note that it is the concentration of each hazardous ingredient in mixture C that must be intermediate to the concentrations of the same hazardous ingredient in mixtures A and B.

For example:

Table 2.3 Hypothetical concentrations of Ingredients X, Y and Z present in Mixtures A, B, C where the concentration of Ingredient Z is higher in Mixture C than in Mixtures A and B

	Mixture A (tested) Classification: STOT-RE — Category 2	Mixture B (tested) Classification: STOT-RE — Category 2	Mixture C (untested)
Ingredient X (non-hazardous)	80%	65%	68%
Ingredient Y (hazardous)	15%	25%	20%
Ingredient Z (hazardous)	5%	10%	12%

In the above example, the concentration of hazardous ingredient Y in mixture C (20%) is intermediate to the concentrations of hazardous ingredient Y in mixtures A (15%) and B (25%). However, the concentration of hazardous ingredient Z in mixture C (12%) is higher than the concentrations of hazardous ingredient Z in both mixtures A (5%) and B (10%). Thus, the Interpolation bridging principle cannot be used. The supplier must refer again to the Subpart of Part 8 that deals with the health hazard class under review (in this example, Subpart 9 of Part 8), and continue with the next provision in the procedure for the classification of mixtures in that health hazard class.

Discussion of subsection 2.3(7) of the Hazardous Products Regulations

The "Substantially similar mixtures" bridging principle may be applied, as specified, to the classification of mixtures in all health hazard classes set out in Part 8 of the HPR, except Subparts 11 and 12 (Biohazardous Infectious Materials and Health Hazards Not Otherwise Classified, respectively).

The following illustrates the bridging principle regarding substantially similar mixtures where Mixture D has been tested and Mixture E is untested.

Table 2.4 Concentration of Ingredients A and B in Mixture D

Mixture D (tested) Classification: Skin Irritation — Category 2
Ingredient A	10%
Ingredient B	90%

Table 2.5 Concentration of Ingredients B and C in Mixture E

Mixture E (untested) Classification: Skin Irritation — Category 2
Ingredient B	90%
Ingredient C	10%

Ingredient A and ingredient C are both classified in Skin Irritation — Category 2, and based on established scientific principles, they do not affect the classification of ingredient B.

Note: Although subsection 2.3(7) of the HPR refers to "ingredient A" and "ingredient B", this provision applies also if ingredients A and B are in fact mixtures.

Discussion of subsection 2.3(8) of the Hazardous Products Regulations

The "Aerosols" bridging principle may be applied, as specified, to the classification of mixtures in the health hazard classes set out in Subparts 1 to 4, 8 and 9 of Part 8 of the HPR (Acute Toxicity, Skin Corrosion/Irritation, Serious Eye Damage/Eye Irritation, Respiratory or Skin Sensitization, STOT- SE, and STOT-RE respectively). This bridging principle does not apply to Subparts 5, 6, 7, 10, 11 or 12 of Part 8 of the HPR (Germ Cell Mutagenicity, Carcinogenicity, Reproductive Toxicity, Aspiration Hazard, Biohazardous Infectious Materials or Health Hazards Not Otherwise Classified, respectively).

This bridging principle is based on the concept that changing a mixture to an aerosol form does not make the mixture more hazardous with respect to its health hazards unless the propellant itself presents a health hazard. For this reason, a mixture to which a propellant is added is attributed the same health hazard classification as the tested non-aerosolized form of the mixture (that is, without the propellant), unless the propellant itself presents a health hazard. Propellants are often flammable (for example, light hydrocarbons such as butane or isobutane) and may affect the classification of a mixture in 1 or more of the physical hazard classes, such as the Aerosols hazard class. However, the addition of a propellant to a mixture in an aerosol dispenser is less likely to affect the classification of the mixture in the health hazard classes.

Other principles

These principles may apply to the classification of a mixture in any health hazard class. There is no specific reference to them within the respective Subparts of Part 8; however, they must always be considered as part of the classification process.

Discussion of subsection 2.4(1) of the Hazardous Products Regulations

When classifying a mixture based on data available in relation to the ingredients in the mixture, all data related to any synergistic effects between the individual ingredients in the mixture must be used in the evaluation. An interaction that produces synergistic effects results in a mixture that is more hazardous than the sum of the hazards of the interacting ingredients.

Discussion of subsection 2.4(2) of the Hazardous Products Regulations

When classifying a mixture in a health hazard class, if a supplier uses data that show negative or counteractive effects of one ingredient on another ingredient (that is, antagonistic effects), this data must be conclusive and based on established scientific principles. Otherwise, the data showing antagonistic effects must not be used for the purpose of classifying the mixture. The consideration of antagonistic effects is subject to a higher scientific standard than the consideration of synergistic effects. The reason for the higher standard is that the consideration of antagonistic effects might result in the classification of a mixture in a less severe category of a particular health hazard class, or even no classification at all in that health hazard class.

Discussion of subsection 2.5(1) of the Hazardous Products Regulations

This provision applies to the classification of mixtures in all of the health hazard classes except for Subpart 11 of Part 8 of the HPR (Biohazardous Infectious Materials), for which no concentration limit has been specified.

When classifying a mixture in a particular category or subcategory of a hazard class based on data available for the ingredients of the mixture, if there are data showing that an ingredient still presents the hazard at a concentration which is lower than the applicable concentration limit (cut-off value), then the mixture must be classified in that category or subcategory of that hazard class. This provision takes precedence over the concentration cut-off value.

For example, consider a mixture that contains an ingredient which, when evaluated individually, meets the criteria for Respiratory Sensitization — Category 1A and which is present in the mixture at a concentration of 0.05%. The concentration limit for the classification of a mixture in Respiratory Sensitization — Category 1A based on ingredient data is 0.1%. However, there are data which demonstrate that the ingredient presents the hazard of respiratory sensitization, even at a concentration of 0.05%. Therefore, based on subsection 2.5(1) of the HPR, the mixture must be classified in Respiratory Sensitization — Category 1A.

In a situation where subsection 2.5(1) of the HPR is applied, the ingredient that triggered the classification of the mixture in a category or subcategory of a health hazard class must be disclosed on the safety data sheet under item 3. Further information on ingredient disclosure on safety data sheets can be found in the discussion of Schedule I in Part 4 of this guidance.

This provision does not apply to Subpart 11 of Part 8 of the HPR because there is no concentration limit for the classification of mixtures as Biohazardous Infectious Materials. Biohazardous infectious materials can present a health hazard even when present in a mixture in miniscule amounts.

Discussion of subsection 2.5(2) of the Hazardous Products Regulations

This provision applies to the classification of mixtures in all of the health hazard classes except for Subpart 11 of Part 8 of the HPR (Biohazardous Infectious Materials), for which no concentration limit has been specified.

When classifying a mixture in a particular category or subcategory of a hazard class, based on data available for the ingredients of the mixture, this provision may be applied if there is appropriate supporting evidence. The provision specifies that, if an ingredient is present in a mixture at a concentration that is equal to or higher than the concentration limit for a particular category or subcategory of a health hazard class, but there are data showing that, based on established scientific principles, the ingredient does not present the hazard at that concentration, then the mixture need not be classified in that category or subcategory of that hazard class due to the presence of that specific ingredient. The data must be scientifically valid, because the outcome of this evaluation may result in no classification for the mixture in the hazard class and category or subcategory under review.

For example, consider a mixture that contains an ingredient at a concentration of 2.0% which, when evaluated individually, meets the criteria for STOT-SE — Category 1. The concentration limit for the classification of a mixture in STOT-SE — Category 1 based on ingredient data is 1.0%. However, the supplier has scientifically valid data which demonstrate conclusively, based on established scientific principles, that the ingredient, when present in a mixture at a concentration of 2.0%, does not present a specific target organ toxicity hazard. Furthermore, there are no other ingredients present in the mixture that is being evaluated, that would trigger classification in STOT-SE — Category 1. Therefore, this mixture would not be required to be classified in STOT-SE — Category 1.

The consideration for subsection 2.5(2) of the HPR is subject to a higher scientific standard than the consideration of subsection 2.5(1) of the HPR because the outcome of this consideration may result in the classification of the mixture in a less severe category, or possibly in no classification at all in the hazard class under review.

In a situation where subsection 2.5(2) of the HPR has been applied with respect to the classification of a mixture that has been determined to be a hazardous product, the ingredient that has been determined not to present the associated hazard in the mixture is still required to be disclosed under item 3 of the safety data sheet, even though this ingredient does not contribute to the classification of the mixture as a hazardous product. Further information on ingredient disclosure on safety data sheets can be found in the discussion of Schedule I in Part 4 of this guidance.

It is important to note that synergistic effects between the ingredients in a mixture must be taken into account before concluding that an ingredient, which is present in a mixture at a concentration that is equal to or higher than the concentration limit for a particular category or subcategory of a health hazard class, does not present the associated hazard. Therefore, the supplier must refer to the requirement specified in subsection 2.4(1) of the HPR. If there are test data that specifically relate to the mixture that is being evaluated, then any synergistic effects between the ingredients present in the mixture will already have been reflected in the test results for the mixture.

Subsection 2.5(2) of the HPR does not apply to Subpart 11 of Part 8 because there is no concentration limit for the classification of mixtures as Biohazardous Infectious Materials. Biohazardous infectious materials can present a health hazard even when present in a mixture in miniscule amounts.

Discussion of section 2.6 of the Hazardous Products Regulations

Section 2.6 of the HPR is intended to ensure that the most conservative approach is taken when classifying a mixture that contains ingredients that could be present at varying concentrations. The classification of the mixture with respect to the health hazard classes must reflect the highest level of hazard that the mixture could present.

If, for example, a mixture contains hazardous ingredient A that is present within an actual concentration range of 10% to 15%, then the highest possible concentration of ingredient A (15%) must be used for the purpose of determining classification in the health hazard classes.

Furthermore, if a supplier has a mixture that contains hazardous ingredients A and B, both of which are present in specific actual concentration ranges, then both A and B must be considered at their highest possible concentrations, even though it may be impossible for the mixture to contain the highest possible concentration of A and the highest possible concentration of B at the same time (that is, if both A and B are present in the mixture at their highest possible concentrations, then the total concentration of ingredients may exceed 100%). The most conservative information must be used (that is, the highest possible concentration of each hazardous ingredient must be used) for the purpose of determining classification in the health hazard classes.

This provision would apply, for example, to the health hazard classification of hazardous products in which hazardous ingredients are present at varying concentrations due to batch-to-batch variability (refer to the discussion of subsection 2.3(1) of the HPR for a discussion of this term).

This requirement also applies when a prescribed concentration range is used in accordance with section 4.5 of the HPR (refer to discussion of section 4.5 of the HPR). For example, where the actual concentration range of ingredient B varies from 4 to 6%, the supplier may choose to withhold the actual concentration range of that ingredient as a trade secret and instead use the prescribed concentration range of 3 to 7% (paragraph 4.5(3)(d) of the HPR). In this case, the actual maximum concentration of 6%, not 7%, must be used for the purpose of determining classification in the health hazard classes.

Further information with regard to concentration ranges can be found in the discussion of section 4.4.1 of the HPR and in the discussion of section 4.5 of the HPR.

Product

Discussion of section 2.7 of the Hazardous Products Regulations

Section 2.7 of the HPR applies to particular physical hazard classes – Subparts 3, 5, 8, 15 and 21 of Part 7 of the HPR (Aerosols, Gases Under Pressure, Self-Reactive Substances and Mixtures, Organic Peroxides, and Chemicals Under Pressure, respectively). For these physical hazard classes, the packaging of the mixture, material or substance, as well as the contents of the packaging, must be considered for the purpose of classification (that is, if a mixture, material or substance in its package are considered together to form a product, it is the overall product that is classified). This provision specifies that, where classification requires consideration of the product as a whole, including its packaging, the same rules with respect to consideration of data must be applied, and the procedures that must be used to determine the classification of the product as a whole are set out in sections 2.1 (for a material or substance) and 2.2 (for a mixture) of the HPR.

For example, in the case of an aerosol that is packaged in a receptacle made of metal, glass or plastic, the aerosol plus the receptacle together form a product and it is the product as a whole that is evaluated for the purpose of classification.

It is important to note that section 2.8 of the HPR (requirement, for certain physical hazard classes, to evaluate solids using data that relate to the physical form in which the solid is sold or imported) must be taken into consideration when evaluating whether a product is classified in a category of a physical hazard class. This provision is discussed below.

Specific Rules

Discussion of section 2.8 of the Hazardous Products Regulations

Subparts 7, 10, 11, 12 and 14 of Part 7 of the HPR are physical hazard classes that specifically relate to solids (Flammable Solids, Pyrophoric Solids, Self-Heating Substances and Mixtures, Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases, and Oxidizing Solids, respectively). Various forms of solids are possible, including massive solid blocks, solid flakes, small pieces, solid granules, solid dusts, powders or particulates. Each of these forms may have different physical and chemical properties, since some physical and chemical properties depend on reactivity which, in turn, depends in part on surface area. For example, dusts have much larger surface areas available for interaction with surrounding oxygen than massive solid blocks. Therefore, dusts may present different hazards than massive solid blocks.

Section 2.8 of the HPR requires the supplier to use data that relate to the solid in the same form as the one in which it is sold or imported (for example, use data on dusts to classify dusts; use data on solid blocks to classify solid blocks, etc.), in order to ensure that the classification reflects the hazards of the product that is being sold or imported.

It is important to note that the Combustible Dusts hazard class is not mentioned here because Subpart 17 of Part 7 of the HPR already specifies that this hazard class applies only to dusts.

Discussion of section 2.9 of the Hazardous Products Regulations

Chapter 4.1 of the GHS provides the following definition and guidance regarding bioavailability: "Bioavailability (or biological availability) means the extent to which a substance is taken up by an organism, and distributed to an area within the organism. It is dependent upon physico-chemical properties of the substance, anatomy and physiology of the organism, pharmacokinetics, and route of exposure. Availability is not a prerequisite for bioavailability".

It should be noted that the definition provided in Chapter 4.1 of the GHS only accounts for systemic effects, since it outlines that the substance must not only be "taken up" by the organism but also "distributed" to another area of the organism. However, several of the health hazard classes under the HPR cover local effects such as skin irritation. To account for these hazard classes, the bioavailability of a mixture, material or substance must be evaluated from both a local and systemic standpoint.

For a mixture, material or substance to have an effect on a biological system, there must be some degree of bioavailability. Therefore, if it can be shown by conclusive experimental data from scientifically validated methods (for example, from Council Regulation (EC) No 440/2008) that a mixture, material or substance is not biologically available for any route of exposure (oral, dermal, inhalation), it does not need to be considered for classification in any health hazard class. A mixture, material or substance may be bioavailable for one route of exposure (oral, dermal, inhalation), but not for others. All routes of exposure must be considered when evaluating bioavailability.

In terms of product classifications, it is important to consider potential interactions between the ingredients that could influence the bioavailability of the mixture. For example, non-bioavailable chemicals may react with other components in a mixture to transform into soluble available forms, which would then require the product to be classified under the HPR.

Bioavailability considerations are only relevant with respect to classification for health hazards.

References for this section of the guidance (Hazardous Products Regulations: Part 2 Classification of a product, mixture, material, or substance)

• 29 CFR 1910.1200, Hazard Communication
• Council Regulation (EC) No 440/2008
• Hazardous Products Act, R.S.C., 1985, c. H-3
• Hazardous Products Regulations, SOR/2015-17
• United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Seventh revised edition, 2017.

Part 3 Labelling

A systematic approach to promoting the safe use of hazardous products in the work place requires the dissemination of information regarding the potential hazards and appropriate safety precautions from the suppliers to the users of the products. Labels and safety data sheets (SDSs) are the main tools for hazard communication. This addresses labelling requirements, whereas Part 4 addresses SDS requirements.

A label serves as the first alert for workers since the label provides basic information about the hazards of a hazardous product and precautionary measures, thereby helping workers to avoid injuries, illnesses and incidents related to the use, handling and storage of the hazardous products. While labels provide important information to the workers, they are limited by the amount of information they can provide.

The following definitions from the Hazardous Products Act (HPA) are relevant to this part of the guidance: "container", "hazardous product", "import", "label", "mixture", "sell", "substance", and "supplier".

Paragraphs 13(1)(b) and 14(b) of the HPA refer to labelling requirements for suppliers who sell or import hazardous products intended for use, handling or storage in a work place in Canada.

Items to note:

• If a Product, Mixture, Material or Substance (PMMS) does not meet the criteria to be classified in any of the HPR hazard classes, that PMMS does not meet the definition of a hazardous product. No label or SDS is required under the HPA for a PMMS that does not meet the definition of a hazardous product under the HPA. There may be labelling requirements under other laws that may apply to products that do not fall under the HPA and HPR.
• Additional information beyond what is required under the HPR may be added to the label to provide further detail, as long as that information is not false or misleading (section 14.2 of the HPA prohibits information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included in a label or SDS for a hazardous product).

Discussion of paragraphs 3(1)(a) and (b) of the Hazardous Products Regulations

As defined in subsection 1(1) of the HPR, "'product identifier' means, in respect of a hazardous product, the brand name, chemical name, common name, generic name or trade name." In addition to the obligation to provide the product identifier on the label of a hazardous product or the container in which the hazardous product is packaged, the same product identifier must also be provided in item 1(a) of the SDS as per section 4.2 of the HPR.

According to subsection 1(1) of the HPR, initial supplier identifier means the name, address and telephone number of (a) the Canadian manufacturer, or (b) the importer of a hazardous product who operates in Canada. This means that, by default, the name, address and telephone number of a Canadian manufacturer or Canadian importer are required to appear on the label of any hazardous product that is sold in or imported into Canada and is intended for use, handling or storage in a work place in Canada. However, where a Canadian distributor sells a hazardous product, the distributor may provide their own name, address and telephone number on the label and SDS in lieu of the name, address and telephone number of the Canadian manufacturer or Canadian importer. Furthermore, a Canadian importer can retain the name, address and telephone number of the foreign supplier on the label and SDS if the hazardous product is imported only for use in their own work place. For further information about these exceptions, see sections 5.8 and 5.9 of the HPR.

As per section 4.2 of the HPR, the product identifier and the initial supplier identifier that are provided on the SDS of a hazardous product must be identical to those provided on the label. In the case that a hazardous product has different product identifiers for each official language (for example, "Product X" and "Produit X"), the requirement of section 4.2 can be met as long as the English product identifier on the SDS matches the English product identifier on the label, and the French product identifier on the SDS matches the French product identifier on the label. It is important to note that if the Canadian distributor provides their name, address and telephone number on the label, then the same contact information of the distributor must be provided on the SDS.

Furthermore, under the HPR, a Canadian supplier who buys a hazardous product, re-labels the hazardous product and then sells it, is considered to be the initial supplier of the hazardous product. In this situation, the Canadian supplier meets the definition of a "manufacturer" under the HPR. The Canadian supplier must provide their name, address and telephone number on the label and SDS.

In the case of a hazardous product that is imported into Canada from a foreign supplier, and the hazardous product is not intended only for use in the importer's own work place (and therefore, does not qualify for the exception specified in section 5.9 of the HPR), it is the Canadian importer (that is, the Canadian party who is responsible for bringing the hazardous product into Canada) whose name, address and telephone number must be provided on the label and SDS. The Canadian importer is responsible for ensuring that the importation of the hazardous product complies with the requirements of the HPA and the HPR.

Additional information beyond what is required may be included on the label and SDS, as long as the information is not false or misleading (section 14.2 of the HPA prohibits information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included in a label or SDS for a hazardous product). Therefore, it would be acceptable for the label and SDS to include the contact information (name, address and telephone number) of both the Canadian importer and the foreign supplier.

Subsections 5.15(1) and (2) of the HPR are labelling exemptions that allow an importer to import hazardous products without labels or with labels that do not comply with the HPR, provided that the intent of the importer is to re-label these hazardous products with HPR compliant labels, in a timely manner and before they are used or sold in Canada. In the situation where an existing label does not contain 1 or more information element(s) required under the HPR, the missing information element(s) must be added to the existing label in a manner that meets the following requirements:

• section 3.3 of the HPR (grouping)
• section 3.4 of the HPR (legibility)
• section 3.5 of the HPR (durability)
• section 14.2 of the HPA (prohibition of misleading information)
• the definition of label under section 2 of the HPA

Discussion of paragraphs 3(1) (c), (c.1), (c.2) and (d) of the Hazardous Products Regulations

A product that is classified as a hazardous product must be labelled using prescribed label information elements. For each hazard class adopted from the GHS in which the hazardous product is classified, except for Chemicals Under Pressure, the corresponding pictogram, signal word, hazard statement and precautionary statements prescribed in section 3 of Annex 3 of the GHS, Seventh Revised Edition are required on the label. For hazardous products classified under the Chemicals Under Pressure hazard class, the corresponding pictogram, signal word, hazard statement and precautionary statements prescribed in section 3 of Annex 3 of the GHS, Eighth Revised Edition are required on the label, with the exception of the hazard statement for Category 3. For hazardous products classified in the category Chemicals Under Pressure – Category 3, the hazard statement "Chemical under pressure: May explode if heated/Produit chimique sous pression : peut exploser sous l'effet de la chaleur" is required on the label, as specified in paragraph 3(1)(c.2) of the HPR.

For all other hazard classes in which the hazardous product is classified, the information elements as set out in Schedule 5 of the HPR for the hazard class are required on the label. In a few instances, information elements are not prescribed (for example, the pictogram for a hazardous product classified in Physical Hazards Not Otherwise Classified (PHNOC) or Health Hazards Not Otherwise Classified (HHNOC) is chosen by the supplier). In these cases, it is up to the supplier to determine the appropriate information elements. The supplier must ensure that the hazardous product or the container in which the hazardous product is packaged has been labelled appropriately. The following prescribed information elements must be provided on the label:

• Pictogram(s)
• Signal word
• Hazard statement(s)
• Precautionary statement(s)
• Supplemental label element(s), if applicable (paragraphs 3(1)(e) to (g) of the HPR)

Any element required by paragraph 3(1)(c), (c.1) and (c.2) of the HPR must be provided, if applicable, in accordance with the specific rules in the following subsections of the HPR:

• 3(2) – Codes or instructions
• 3(3) – Substitution by pictogram
• 3(3.1) – Chemicals under pressure
• 3(4) – Hazard statements – Specific Target Organ Toxicity - Single Exposure
• 3(4.1) – Precautionary statement – Pyrophoric Liquids and Pyrophoric Solids
• 3(4.2) – Hazard statement – Acute Toxicity (Inhalation)
• 3(5) – Information elements for certain categories or subcategories
• 3.6(1) – Specific rule – signal word
• 3.6(2) – Specific rule – hazard statement
• 3.6(3) – Specific rule – symbol

Similarly, any element required by paragraph 3(1)(d) of the HPR must be provided, if applicable, in accordance with the specific rules in subsections 3(2) to (4), and 3.6(1) of the HPR (Codes or instructions, Substitution by pictogram, Hazard statement – STOT-SE and Specific rule – signal word, respectively).

For each category or subcategory of each hazard class in which a product is classified, the following label elements are required:

Pictogram(s)

A pictogram is defined as a symbol along with other graphical elements, such as a border and background colour (defined in subsection 1(1) of the HPR).

The symbols that are required for categories and subcategories of hazard classes are shown in section 3 of Annex 3 of the GHS, Seventh Revised Edition and Schedule 5 of the HPR, with the exception of the symbols that are required for the categories of the Chemicals Under Pressure hazard class, which are shown in section 3 of Annex 3 of the GHS, Eighth Revised Edition.

For Biohazardous Infectious Materials (BIM), the required symbol is found in Schedule 5 of the HPR. Hazardous products classified in PHNOC – Category 1 and HHNOC – Category 1 require a pictogram, but the pictogram is not prescribed by Schedule 5. In this case, the supplier must select the most suitable pictogram from the ones shown in Schedule 3 of the HPR and use it on the label.

Although section 3 of Annex 3 of the GHS provides the symbols (or no symbol) for the categories and subcategories of the GHS hazard classes, the corresponding pictogram(s) in Schedule 3 of the HPR must appear on the label. Subsection 3(3) of the HPR is the provision that requires that the symbol that is specified for the category or subcategory in section 3 of Annex 3 of the GHS or in Schedule 5 be substituted by the pictogram on the label.

Furthermore, although section 3 of Annex 3 of the GHS, Eighth Revised Edition provides the symbols for the categories of the Chemicals Under Pressure hazard class, the corresponding pictogram(s) in Schedule 3 of the HPR must appear on the label. Subsection 3(3.1) of the HPR is the provision that requires that the symbol that is specified for the category in section 3 of Annex 3 of the GHS, Eighth Revised Edition be substituted by the pictogram on the label.

All symbols and related pictograms used in the HPR can be found in Schedule 3 of the HPR.

Pictograms are assigned to categories and subcategories of hazard classes and are intended to convey physical and/or health hazard information about hazardous products. The format of a black symbol on a white background with a red frame in the shape of a square set on a point has been adopted for nearly all HPR hazard classes. The only exception is the BIM hazard class for which the biohazard symbol is set in a round black border.

In some cases, pictograms also convey information regarding the severity of hazard. For example, a product classified in Acute Toxicity - Category 1 will require the skull and crossbones pictogram (more severe), while a product classified in Acute Toxicity - Category 4 will require the exclamation mark (less severe) pictogram:

Figure 1 - Text description

Skull and crossbones in the shape of a red square set at a point 

Figure 2 - Text description

Exclamation mark in the shape of a red square set at a point 

Section 3 of Annex 3 of the GHS and Schedule 5 of the HPR also indicate which categories and subcategories of hazard classes do not require a symbol on the label.

The following hazard categories in a hazard class do not require a symbol:

1. Flammable Gases – Category 2
2. Aerosols – Category 3
3. Flammable Liquids – Category 4
4. Self-Reactive Substances and Mixtures – Type G *
5. Organic Peroxides – Type G*
6. Serious Eye Damage/Eye Irritation – Category 2B
7. Reproductive Toxicity – Effects on or via lactation
8. Combustible Dusts – Category 1 (non-GHS hazard class)
9. Simple Asphyxiants – Category 1 (non-GHS hazard class)

* It is important to note that for a PMMS classified in Self-Reactive Substances and Mixtures (Subpart 8 of Part 7) – Type G and/or Organic Peroxides (Subpart 15 of Part 7) – Type G, there is no prescribed pictogram, signal word, hazard or precautionary statement, or supplemental label elements. For these 2 classifications, only the product identifier and initial supplier identifier are required on the label.

Signal word

The signal word, as defined in subsection 1(1) of the HPR, is used to alert the user of a hazardous product to a potential hazard and to indicate the severity of hazard. There are 2 signal words: "Danger" and "Warning". "Danger" is used for the more severe hazards, while "Warning" is used for less severe hazards. For example, a product classified in Reproductive Toxicity - Category 1 or 1A or 1B will require "Danger" as the signal word, while a product classified in Reproductive Toxicity - Category 2 will require "Warning" as the signal word. The Effects on or via lactation category of the Reproductive Toxicity hazard class is the only hazard category that does not require the use of a signal word but still requires hazard statement(s) and precautionary statement(s). For a hazardous product classified in more than 1 category or sub-category of a hazard class or in more than 1 hazard class, the same signal word, "Danger" or "Warning", is not required to be repeated. It only needs to appear once on the label and once on the SDS. Furthermore, as permitted by subsection 3.6(1) of the HPR, if there is a requirement to provide the signal word "Danger", any requirement to provide the signal word "Warning" on a label does not apply.

The signal word for categories and subcategories of hazard classes adopted from the GHS, except for the Chemicals Under Pressure hazard class, is assigned by section 3 of Annex 3 of the GHS, Seventh Revised Edition. The signal word for the categories of the Chemicals Under Pressure hazard class is assigned by section 3 of Annex 3 of the GHS, Eighth Revised Edition. For the hazard classes not covered by the GHS (Combustible Dusts, Simple Asphyxiants, PHNOC, HHNOC, and BIM), the required signal word is assigned in column 4 of Parts 1 to 6 of Schedule 5 of the HPR.

Hazard statement(s)

In most cases, hazard statements (defined in subsection 1(1) of the HPR), are prescribed phrases that describe the nature of a hazard presented by a hazardous product. For the hazard classes, categories and subcategories adopted from the GHS, except for the Chemicals Under Pressure hazard class, these statements are assigned by section 3 of Annex 3 of the GHS, Seventh Revised Edition. For example, the hazard statement for Acute Toxicity (Oral) - Category 1 is "Fatal if swallowed" and the hazard statement for Acute Toxicity (Oral) - Category 4 is "Harmful if swallowed". For Chemicals Under Pressure – Categories 1 and 2, the required hazard statements are assigned by section 3 of Annex 3 of the GHS, Eighth Revised Edition. For Chemicals Under Pressure – Category 3, the required hazard statement is prescribed in paragraph 3(1)(c.2) of the HPR.The hazard statements for the hazard classes not covered by the GHS (Combustible Dusts, Simple Asphyxiants, PHNOC, HHNOC, and BIM) are found in column 5 of Parts 1 to 6 of Schedule 5 of the HPR.

It is important to note that, unlike the hazard statements required for all other hazard classes, the hazard statements required for PHNOC, HHNOC and BIM hazard classes are not prescribed. The supplier must identify and use appropriate wording to describe the nature of the PHNOC, HHNOC or BIM hazard.

In addition, there is an exemption in subsection 5.4(1) of the HPR for hazardous products in a container that has a capacity of less than or equal to 100 ml. Hazardous products in a container that has a capacity of less than or equal to 100 ml must include the following information on the label: the product identifier, the initial supplier identifier, the applicable pictogram(s), signal word, and supplemental label elements, if applicable. However, the label of such a hazardous product is not required to bear any hazard statement or precautionary statement.

Furthermore, hazard statements may be combined under specific conditions and repetition of a hazard statement must be avoided.

For the Germ Cell Mutagenicity, Carcinogenicity, Reproductive Toxicity, Specific Target Organ Toxicity – Single Exposure (STOT-SE) and Specific Target Organ Toxicity - Repeated Exposure (STOT-RE) hazard classes, the hazard statements set out in section 3 of Annex 3 of the GHS include some instructions in italics and in parentheses, such as: (state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard); (state specific effect if known); (or state all organs affected if known). The instructions "state specific effect if known" and "or state all organs affected if known" should be understood as an obligation to disclose any known specific effects and/or affected organs.

For example, if a hazardous product classified in STOT-SE causes adverse liver effects, the label must provide this information even though it is not certain whether the liver is the only organ affected. Therefore, any known affected organ must appear on the HPR label (as part of the required hazard statement), even if all of the affected organs are not known. As an additional example, if a hazardous product is classified in Reproductive Toxicity because it reduces sperm count, even though this effect may not be the only one, this information must appear on the label of this hazardous product.

Precautionary statement(s)

In most cases, precautionary statements (defined in subsection 1(1) of the HPR) are prescribed statements that describe the recommended measures to take in order to minimize or prevent adverse effects resulting from exposure to, or improper storage or handling of, a hazardous product. For those hazard classes, categories and subcategories adopted in the HPR from the GHS, except for the Chemicals Under Pressure hazard class, precautionary statements are found in section 3 of Annex 3 of the GHS, Seventh Revised Edition. For the categories of the Chemicals Under Pressure hazard class, precautionary statements are found in section 3 of Annex 3 of the GHS, Eighth Revised Edition.

Section 3 of Annex 3 includes 4 types of precautionary statements covering: prevention; response (first aid measures, accidental spillage or exposure); storage; and disposal. For example, "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking" is used for the Flammable Liquids hazard class.

It is important to note that while paragraph 3(1)(c) of the HPR refers to "precautionary statement" (singular), unless the small capacity container exemption set out in subsection 5.4(1) of the HPR applies, the label of a hazardous product must provide all of the precautionary statements that are specified in section 3 of Annex 3 of the GHS, for each category or subcategory of each hazard class in which the hazardous product is classified. However, as per subsections 3.2(1) and (2) of the HPR, precautionary statements could be combined (HPR 3.2(1)) or omitted (HPR 3.2(2)) under specific conditions.

For hazard classes not covered by the GHS (Combustible Dusts, Simple Asphyxiants, PHNOC, HHNOC, and BIM), the supplier must provide appropriate precautionary statements in terms of general, prevention, response, storage and disposal precautions. There are no prescribed precautionary statements for these hazard classes.

It is important to note that for the hazard classes that are not covered by the GHS, there is a requirement to provide "general" precautionary statements, if such statements apply. For example, a general precautionary statement could be "Read the label and safety data sheet before use". The "general" precautionary statements are not required for the hazard classes that are adopted from the GHS.

Supplemental label elements

Discussion of paragraphs 3(1)(e), (f) and (g) of the Hazardous Products Regulations

The supplemental label elements specified in paragraphs 3(1)(e) and (f) of the HPR are only required for certain hazardous products that fall within the Acute Toxicity hazard class.

If the hazardous product is a mixture that is classified in Acute Toxicity (Category 1, 2, 3 or 4) based on ingredient(s) for which the acute toxicity is known and the hazardous product contains ingredients of unknown acute toxicity, a prescribed supplemental label element is required. The route of exposure should be included in the statement. The supplemental label element is required only for the route(s) of exposure with respect to which the hazardous product is classified. For example, if a hazardous product is classified in Acute Toxicity (Oral) – Category 1 based on ingredient(s) for which the acute oral toxicity is known and the hazardous product contains, at a concentration of 5%, ingredients of unknown acute oral toxicity, then the following supplemental label element is required:

5% of the mixture consists of ingredient(s) of unknown acute oral toxicity.

This supplemental label element could apply more than once in the situation where a mixture ends up being classified for more than 1 route of exposure based on ingredients of known acute toxicity. For example, if a mixture is classified as acutely toxic through inhalation and oral routes based on ingredient(s) of known acute toxicity, and 2% of this mixture consists of ingredients of unknown acute oral toxicity and 10% of the same mixture consists of ingredients of unknown acute inhalation toxicity, then the following statements must appear on the label of the hazardous product:

2 % of the mixture consists of ingredient(s) of unknown acute oral toxicity.

10 % of the mixture consists of ingredient(s) of unknown acute inhalation toxicity.

Alternatively, the following combined statement could be used:

2% and 10% of the mixture consists of ingredients of unknown acute oral and inhalation toxicity, respectively.

It is important to note the following:

• if the hazardous product does not meet any of the criteria for Acute Toxicity - Category 1, 2, 3 or 4, by any route of exposure, this supplemental label element is not required
• if the hazardous product meets the criteria for Acute Toxicity – Category 1, 2, 3 or 4, by any route of exposure, and the hazardous product does not contain any ingredients of unknown acute toxicity (that is, if the acute toxicity is known for all the ingredients), then this supplemental label element is not required

If, upon contact with water, the hazardous product emits a toxic gaseous substance for which the LC₅₀ value falls within 1 of the ranges specified in Table 3 to subsection 8.1.1(3) of the HPR, a prescribed supplemental label statement is required. Such hazardous products are also referred to as Water-Activated Toxicants. The prescribed supplemental label statement is: "In contact with water, releases gases which are fatal/toxic/harmful if inhaled". "Fatal" is required for hazardous products that release a gaseous substance that is classified in Category 1 or 2. "Toxic" is required for hazardous products that release a gaseous substance that is classified in Category 3. "Harmful" is required for hazardous products that release a gaseous substance that is classified in Category 4.

For example, consider a substance which is classified in Acute Toxicity (Inhalation) – Category 2, and which, in contact with water, releases a gaseous substance with an LC₅₀ of 600 ppmV. The gaseous substance which is released is classified in Acute Toxicity (Inhalation) – Category 3. The following hazard statements would be required:

Fatal if inhaled.

In contact with water, releases gases which are toxic if inhaled.

Paragraph 3(1)(g) of the HPR also addresses Water-Activated Toxicants. It prescribes the same supplemental label statements as paragraph 3(1)(f) of the HPR. However, paragraph 3(1)(g) specifically addresses hazardous products which, in the absence of contact with water, would not meet the criteria to be classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4, but which, in contact with water, emit a toxic gaseous substance for which the LC₅₀ value falls within 1 of the ranges specified in Table 3 to subsection 8.1.1(3) of the HPR. Such hazardous products are classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4, depending on the LC₅₀ value of the emitted gaseous substance, by virtue of subsection 8.1.1(2) of the HPR.

The following prescribed supplemental label element is required: "In contact with water, releases gases which are fatal/toxic/harmful if inhaled". "Fatal" is required for hazardous products that release a gaseous substance that is classified in Category 1 or 2. "Toxic" is required for hazardous products that release a gaseous substance that is classified in Category 3. "Harmful" is required for hazardous products that release a gaseous substance that is classified in Category 4.

For example, consider a substance which, in the absence of contact with water, does not meet the criteria to be classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4, but which, in contact with water, releases a gaseous substance with an LC₅₀ of 300 ppmV. In accordance with subsection 8.1.1(2) of the HPR, this substance would be classified in Acute Toxicity (Inhalation) ─ Category 2. As specified in subsection 3(4.2) of the HPR, hazardous products classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4 by virtue of subsection 8.1.1(2) of the HPR are not required to have the GHS-prescribed hazard statement, namely, "[Fatal/toxic/harmful] if inhaled" on their labels. Therefore, in this example, the following hazard statement would be required:
In contact with water, releases gases which are fatal if inhaled.

Discussion of subsection 3(2) of the Hazardous Products Regulations

Section 3 of Annex 3 of the GHS contains alphanumeric codes that have been assigned to each hazard statement and precautionary statement. These alphanumeric codes need not appear on a label and must not, under any circumstances, replace the hazard statement or precautionary statement to which they relate. In the event where a supplier chooses to indicate the codes on a label, the supplier must ensure that this information does not contravene section 14.2 of the HPA which prohibits information that is false, misleading or likely to create an erroneous impression, with respect to the information that is required to be included on a label or SDS.

As an example, the alphanumeric code H225 is assigned under the GHS to the hazard statement "Highly flammable liquid and vapour". This hazard statement is required for flammable liquids with a flash point below 23°C and an initial boiling point >35°C. In this case, the supplier does not have to include the code H225 on the label or SDS. This same principle extends to the alphanumeric codes assigned to the prescribed precautionary statements (P codes).

In addition, section 3 of Annex 3 of the GHS and Schedule 5 of the HPR contain instructions in italics. These instructions are meant for suppliers or competent authorities and must not be included in the content of a label. For example, in Schedule 5 of the HPR, the instructions for PHNOC "Wording that describes the nature of the hazard" must not appear on the label; it is meant for the supplier to provide the appropriate hazard statement for a hazardous product classified as PHNOC. Similarly, the instruction "state all organs affected if known" for STOT-SE, in section 3 of Annex 3 of the GHS, is meant for the supplier to list the organs affected, if known by the supplier.

Section 3 of Annex 3 of the GHS also contains instructions that are not in italics. These instructions are meant for suppliers or competent authorities and must not be reproduced per se in the content of a label or safety data sheet, but the suppliers must follow the instructions and modify the content of the label accordingly. For example, for a hazardous product classified in STOT-SE – Category 1 or STOT-RE – Category 1, the precautionary statement "Wash … thoroughly after handling" is listed in section 3 of Annex 3 of the GHS. The following instructions appear below the precautionary statement: "Manufacturer/supplier or the competent authority to specify parts of the body to be washed after handling". In this case, the supplier must not include these instructions on the label, but must specify the parts of the body to be washed after handling. For example, if hands must be washed after handling, then this precautionary statement would read, "Wash hands thoroughly after handling".

In situations where the instruction below the precautionary statement reads "Manufacturer/ supplier or competent authority may further specify type of equipment where appropriate", the supplier has a choice of whether to specify the type of equipment.

Discussion of subsection 3(3) and 3(3.1) of the Hazardous Products Regulations

A pictogram, as defined in subsection 1(1) of the HPR, is a graphical composition that includes a symbol along with other graphical elements, such as a border and background colour. Although section 3 of Annex 3 of the GHS and Schedule 5 of the HPR provide a symbol for each hazard category or subcategory of each hazard class, the corresponding pictogram(s) in Schedule 3 of the HPR is what must appear on the label.

Although section 3 of Annex 3 of the GHS, Eighth Revised Edition provides 1 or more symbol(s) for each hazard category of the Chemicals Under Pressure hazard class, the corresponding pictogram(s) in Schedule 3 of the HPR is what must appear on the label.

Discussion of subsections 3(4), (4.1) and (4.2) of the Hazardous ProductsRegulations

For STOT-SE – Category 3 (subpart 8 of Part 8 of the HPR), 2 independent hazard statements are provided in section 3 of Annex 3 of the GHS: one relates to respiratory tract irritation (May cause respiratory irritation) and the other relates to narcotic effects (May cause drowsiness or dizziness). Therefore, the statement that must appear on the label must relate to the hazard (respiratory tract irritation or narcotic effects) for which the hazardous product is classified (at a minimum, at least 1 statement must appear). For example, if the hazard presented is respiratory tract irritation, then the hazard statement "May cause respiratory irritation" must appear on the label; if the hazard presented is narcotic effects then the hazard statement "May cause drowsiness or dizziness" must appear on the label.

If the hazardous product presents both hazards, then both hazard statements are required on the label (that is, the hazard statements "May cause respiratory irritation" and "May cause drowsiness or dizziness" must appear on the label). As specified in subsection 3.2(3) of the HPR, the hazard statements could be combined into the following combination hazard statement: "May cause respiratory irritation and drowsiness or dizziness".

The terms "respiratory tract irritation" and "narcotic effects" are defined in Subpart 8 of Part 8 of the HPR.

For Pyrophoric Liquids – Category 1 and Pyrophoric Solids – Category 1 (Subparts 9 and 10 of Part 7 of the HPR, respectively), Section 3 of Annex 3 of the GHS sets out prevention and response precautionary statements.

In addition to the prevention and response precautionary statements set out in section 3 of Annex 3 of the GHS, subsection 3(4.1) of the HPR specifies that a storage precautionary statement is required for hazardous products classified as Pyrophoric Liquids – Category 1 or Pyrophoric Solids – Category 1. If the contents of the hazardous product are handled and stored under inert gas, the precautionary statement "Handle and store contents under inert gas" must be used on the label. If the contents of the hazardous product are handled and stored under a liquid or gas other than inert gas, the precautionary statement "Handle and store contents under [insert the name of the liquid or gas]" must be used on the label.

Subsection 3(4.2) of the HPR applies to hazardous products that are classified in Acute Toxicity (Inhalation) — Category 1, 2, 3 or 4 based on the application of subsection 8.1.1(2) of the HPR. Subsection 8.1.1(2) specifically addresses products which, in the absence of contact with water, do not meet the criteria to be classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4, but which, in contact with water, emit a toxic gaseous substance for which the LC₅₀ value falls within 1 of the ranges specified in Table 3 to subsection 8.1.1(3) of the HPR. Due to their water-activated toxicity hazard, such hazardous products are classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4, depending on the LC₅₀ value of the emitted gaseous substance.

Hazardous products classified in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4 based on the application of subsection 8.1.1(2) of the HPR are not required to have the GHS-prescribed hazard statement, namely, "Fatal/toxic/harmful if inhaled" on their labels. However, as specified in paragraph 3(1)(g) of the HPR, the following supplemental label element is required: "In contact with water, releases gases which are fatal/toxic/harmful if inhaled". Refer to the discussion of paragraph 3(1)(g) of the HPR for further guidance.

Discussion of subsection 3(5) of the Hazardous Products Regulations

If a hazardous product is classified in 1 of the hazard categories specified in subsection 3(5), the label elements specified in section 3 of Annex 3 of the GHS are required. This provision provides the requirements with respect to specific cases in which 1 or more of the following applies:

• The name of the hazard class in the HPR is not exactly the same as in section 3 of Annex 3 of the GHS
• Section 3 of Annex 3 of the GHS provides the labelling elements for hazardous products classified in a subcategory (for example, Subcategory 1A) of a hazard class but does not provide labelling elements for hazardous products classified in the category (for example, Category 1)
• Section 3 of Annex 3 of the GHS provides the labelling elements for a category (for example, Category 1) but does not provide labelling elements for hazardous products further classified in a subcategory (for example, Subcategory 1A)
  • For example, in the case of a hazardous product classified in Eye Irritation – Category 2 of the HPR (without further sub-classification), section 3 of Annex 3 of the GHS does not clearly specify which labelling elements would be required. Subparagraph 3(5)(i) of the HPR indicates that, for such a hazardous product, the required label elements are those specified for Eye Damage/Irritation – Hazard category 2A, in section 3 of Annex 3 of the GHS. For hazardous products classified in Eye Irritation – Category 2A or 2B of the HPR, the required label elements are those specified for Eye Damage/ Irritation – Hazard category 2A or 2B, respectively, in section 3 of Annex 3 of the GHS. This is set out in subparagraph 3(5)(j) of the HPR

It is important to note that in section 3 of Annex 3 of the GHS the title "Hazard category" may refer to a category or subcategory or both (for example, Respiratory Sensitization Hazard Category 1, 1A, or 1B).

Discussion of section 3.1 of the Hazardous Products Regulations

"An exact reproduction" of the pictogram required to be provided on a label means that the proportion of the frame versus the symbol must be in accordance with the pictogram as shown in Schedule 3 of the HPR.

An empty pictogram border, for example a square red frame set at a point without a hazard symbol, is not a pictogram and is not acceptable since this image would be considered as false or misleading information, which is prohibited under section 14.2 of the HPA. In other words, empty pictogram borders (for example: red borders with no symbol) are not permitted. However, a blacked out pictogram frame is acceptable as it is not a square red frame set at a point without a hazard symbol. If a blank red frame is not fully covered or filled in, the label is not acceptable. The red frame along with the inside of the frame is required to be completely blacked out.

A specific pictogram should appear only once on a label, even if the classification of the hazardous product results in assignment of the same pictogram for multiple hazards. For example, if a hazardous product is classified in STOT-SE – Category 1 as well in Reproductive Toxicity – Category 1, the health hazard symbol is required for both classifications but must appear only once. In this case, the repetition of the health hazard symbol would be considered as false or misleading information because it could lead the user of the product to believe that the product is more hazardous than it is. Multiple, identical pictograms on a hazardous product label are not permitted and would be considered non-compliant under the HPR.

With regard to pictogram sizes, there is no minimum size prescribed in the HPR; however, the pictogram must be legible in accordance with section 3.4 of the HPR.

The BIM pictogram is not found in the GHS and has often been used with a circular border even in contexts that are not WHMIS-related. Therefore, the BIM pictogram retains its existing round, black border.

For all pictograms, the background colour must be white. A background colour other than white is not acceptable.

Discussion of subsections 3.2(1), (2) and (3) of the Hazardous Products Regulations

Precautionary statements may be combined if the combination provides the same information as would have been conveyed by each of the individual precautionary statements. For example, "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources; No smoking,"; "Store in a well-ventilated place,"; and "Keep cool" may be combined to read: "Keep cool, in a well-ventilated place, away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking".

The prescribed precautionary statements in the GHS may not apply in certain circumstances. Inapplicable precautionary statements with regard to the normal conditions of use, handling and storage of hazardous products can be omitted from the label.

Section 3 of Annex 3 of the GHS does combine prescribed response and storage precautionary statements in some instances. As an example, the prescribed response and storage precautionary statements assigned to Flammable Liquids - Category 2 include:

• P303+P361+P353 "IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse with water [or shower]."
• P370+P378 "In case of fire: Use…to extinguish.", and
• P403+P235 "Store in well-ventilated place. Keep Cool."

It is important to note that, as specified in subsection 3(2) of the HPR, the alphanumeric codes assigned to the hazard and precautionary statements are not required on the label and must not, under any circumstances, replace the hazard statement or precautionary statement to which they relate.

It is also important to note that not all hazard classes have precautionary statements prescribed for each type of statement (prevention, response, storage, and disposal). For instance, prevention and response precautionary statements are prescribed for Flammable Solids, while only storage precautionary statements are prescribed for Gases Under Pressure, in the categories of compressed gas, liquefied gas, and dissolved gas.

When a forward slash or diagonal mark [/] appears in a precautionary statement in section 3 of Annex 3 of the GHS, it indicates that the supplier can select only the phrases that are applicable. For example, "Wear protective gloves/protective clothing/eye protection/ face protection" could read, "Wear eye protection" (as appropriate for the safe handling of the hazardous product).

When 3 full stops […] appear in a precautionary statement in section 3 of Annex 3 of the GHS, the 3 full stops indicate that not all applicable conditions may be listed. For example, "Use explosion-proof electrical/ ventilating/lighting/…/equipment", the use of "…" indicates that the supplier, as applicable and appropriate for the hazardous product, may specify other equipment.

For precautionary statements, the text in italics in section 3 of Annex 3 of the GHS indicates specific conditions applying to their use or allocation. There may be a condition to trigger the presence of a specific precautionary statement on the label. For example, in the Flammable Liquids hazard class, the precautionary statement "Keep container tightly closed" is required if the liquid is volatile and may generate an explosive atmosphere.

Hazard statements may be combined where appropriate, if the combination conveys the same information as would have been conveyed by each of the individual statements. For example, "Fatal if swallowed" and "Fatal if inhaled" can be combined to read "Fatal if swallowed or if inhaled".

Discussion of section 3.3 of the Hazardous Products Regulations

Under section 2 of the HPA, a label is defined as "a group of written, printed or graphic information elements that relate to a hazardous product, which group is designed to be affixed to, printed on or attached to the hazardous product or the container in which the hazardous product is packaged". Section 3.3 of the HPR specifies that among those information elements, the pictogram(s), signal word, and hazard statement(s) must be grouped together on the label.

There is no mandatory or prescribed format for the grouping of the pictogram(s), signal word and hazard statement(s). In the examples shown in Annex 7 of the GHS, the pictogram(s) are placed at the left and the signal word and hazard statements are placed immediately to the right of the pictogram(s), with no other text or graphics placed in between. Such an arrangement would meet the requirement of Section 3.3 of the HPR. An arrangement whereby the items are placed one directly below the other, with no other text or graphics placed in between the pictogram(s), signal word and hazard statement(s), would also meet this requirement.

Products packaged in multi-compartment containers

Multi-compartment products are products that contain at least 2 PMMS in separate compartments (see example in Figure 3 below). They may be designed either to allow, or not to allow, access to the individual PMMS.

Figure 3 - Text description

A container containing 2 PMMS in separate compartments  

In the case of a multi-compartment product that contains 1 or more hazardous products, each hazardous product must be labelled appropriately. Each label must be placed on a surface of the container that makes it obvious that it refers to the relevant hazardous product in the multi-compartment container. Either the information elements for each individual hazardous product can be provided separately, each on its own label, or all information elements for all the hazardous products can be provided on a single label.

It is important to note that the provision set out in subsection 4.1(1) of the HPR (Instructions for use – new material or substance) applies to safety data sheets and not to labels. However, the supplier may provide information regarding the new material or substance on the label.

The example below depicts a sample label that meets the requirement of Section 3.3 of the HPR. In this sample label, the pictograms, signal word and hazard statements are grouped together at the top of the label, with no other text or graphics placed in between. Therefore, this sample label is compliant with the requirement of Section 3.3 of the HPR. This example is for informational purposes only and is not meant to represent the only label suppliers may create for these hazards.

Figure 4 - Text description

Sample label where the pictograms, signal word and hazard statements are grouped together at the top of the label 

A sample label that does not meet the requirement of section 3.3 of the HPR is illustrated below. In this sample label, the signal word and hazard statements are located together at the top of the label; however, the pictograms are located near the bottom. Precautionary statements are located in the middle of the label, between the hazard statements and the pictograms. The pictograms, signal word and hazard statements are not grouped together in this sample label and therefore, it does not meet the requirement of section 3.3 of the HPR.

Figure 5 - Text description

Sample label where the signal word and hazard statements are at the top of the label and the pictograms are at the bottom of the label 

Precautionary statements are not required to be grouped with the pictogram, signal word, and hazard statement(s), but must nonetheless appear on the label, unless an exception applies (refer to subsection 3.2(2) of the HPR and Part 5 of this guidance for additional information on exceptions).

Discussion of section 3.4 of the Hazardous Products Regulations

The label elements must appear on a surface of the container that is visible under normal conditions of use (for example, not on the bottom of a bottle). In the case of hazardous products for which the container is a compressed gas cylinder (for example, for the Gases Under Pressure hazard class), it is acceptable to place the label on the shoulder of the compressed gas cylinder, as long as, in accordance with section 3.5 of the HPR (discussed below), the label remains affixed to, printed or written on, or attached to the container and remains legible under normal conditions of transport and use.

The HPR does not specify any requirements with regard to the shape of the label (for example, rectangular vs. square vs. circular). The shape of the label is left to the discretion of suppliers. With regard to sizes, there is no minimum size prescribed in the HPR; however, the text and pictograms must be sufficiently large to be legible.

The label must also be legible without the aid of any device, other than corrective lenses. In other words, a label that is only in a QR code form that requires a scanner (a device, for retrieving information) would not meet the requirements of the HPA and HPR.

Figure 6 - Text description

Sample QR code that does not meet the requirements of the HPA and HPR 

Suppliers must ensure that the information elements required by the HPR are laid out on the label or container in a manner that will contrast and stand out from any other information on the label, or from any other information on the hazardous product or container in which the hazardous product is packaged.

The following are some examples that would not meet the requirements of the HPR, as the information elements on the label or container are not considered to be clearly and prominently displayed and easily legible, and are not considered to contrast with other information:

• a clear plastic over label bearing the required information is applied over other graphic matter
• the precautionary statement is printed in a shade or colour that does not contrast sufficiently with the background
• the information elements are embossed and in the same colour as the background packaging material in the case of a transparent container
• the required information elements are placed on the back of a label on the container so that a person would have to look through the contents of the container to see the information

Discussion of section 3.5 of the Hazardous Products Regulations

Information elements must remain legible throughout the lifetime of the hazardous product, and not fade, run, rub off, peel off or deteriorate upon exposure to light under normal conditions of use or transport. Print that can be dissolved by the contents, or paper and plastic label sleeves that are easily removable, do not comply with section 3.5 of the HPR. Placing the required safety information on a removable wrapper would not be sufficiently durable to provide a user with the necessary information needed at the time of use of the hazardous product, especially if the hazardous product is intended to be used more than once.

Section 3.5 of the HPR does not apply to the sale or importation of a hazardous product in a container having a capacity of less than or equal to 3 ml if the label interferes with the normal conditions of use of the hazardous product (subsection 5.4(2) of the HPR). In these situations, the label could be affixed in such a manner that it would be easy to remove before use.

Discussion of subsections 3.6(1), (2) and (3) of the Hazardous Products Regulations

Section 3.6 of the HPR is meant to reduce the amount of information displayed on a label. Under the specified conditions, if a more severe symbol, signal word and/or hazard statement are required to be disclosed, there is no need to also disclose the less severe symbol, signal word and/or hazard statement.

Example of a label

The example below depicts a sample label that meets the HPR requirements. This example is for informational purposes only and is not meant to represent the only label suppliers may create for these hazards. This label represents a substance or mixture that is classified in the categories: "Acute Toxicity, Oral – Category 1 or 2" and "Skin Corrosion/Irritation- Category 2". As noted previously, the supplier identifier must be that of a Canadian importer or manufacturer and there is no requirement for a label border.

Figure 7 - Text description

Sample label that meets the HPR requirements regarding "Acute Toxicity, Oral – Category 1 or 2" and "Skin Corrosion/Irritation- Category 2"

References for this section of the guidance (Hazardous Products Regulations: Part 3 Labelling)

• 29 CFR 1910.1200, Hazard Communication
• Hazardous Products Act, R.S.C., 1985, c. H-3
• Hazardous Products Regulations, SOR/2015-17
• United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Seventh revised edition, 2017.
• United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Eighth revised edition, 2019.

Part 4 Safety data sheet

A safety data sheet (SDS) is a document that describes the hazards associated with a hazardous product, and that provides information on safe use, handling, storage and disposal procedures. The SDS provides more detailed information about a hazardous product than the label.

The requirements for the provision of information on SDSs are set out in Part 4, Schedule 1 and Schedule 2 of the Hazardous Products Regulations (HPR). Suppliers who sell a hazardous product that is intended for use, handling or storage in a work place in Canada are required to have in their possession an SDS for the hazardous product that meets the requirements of the HPR (paragraph 13(1)(a) of the Hazardous Products Act (HPA)). Upon sale in Canada, a supplier must provide the SDS to the person or government who received the hazardous product (paragraph 13(1)(a.1) of the HPA). Similarly, suppliers who import a hazardous product that is intended for use, handling or storage in a work place in Canada are required to obtain or prepare, on or before the importation, an SDS for the hazardous product that meets the requirements of the HPR (paragraph 14(a) of the HPA).

Note:

The supplier of a hazardous product is responsible for ensuring that the SDS pertaining to the product is accurate, up-to-date and compliant with the HPR, upon the sale or importation of the product into Canada.

An SDS can be provided either as a paper document or as any type of electronic document that can be read using a computer or another device (More information about additional requirements for SDSs and ways of providing SDSs can be found in Part 6 of this guidance).

SDSs are only required for hazardous products within the meaning of the HPA that are not excluded from the application of the HPA. That is, an SDS must be prepared for a product, mixture, material or substance (PMMS) that meets the classification criteria for at least 1 physical or health hazard class in the HPR, unless the PMMS falls within 1 of the excluded product categories listed in section 12 and Schedule 1 of the HPA or there is an exclusion from an SDS under Part 5 of the HPR.

Use of generic SDSs

Although there is no specific provision in the HPR regarding the use of generic SDSs, it is acceptable to use a generic SDS for a series of hazardous products with similar chemical composition that are all classified in the same hazard class(es) and category(ies) or subcategory(ies), provided that the SDS meets the HPR requirements for each of the hazardous products to which it relates. For example, a generic SDS can be used for a series of paints where the only difference from one hazardous product to another is the pigment used. In such a case, the supplier would be required to list all of the hazardous products to which the SDS applies under the product identifier in item 1 (Identification) of the SDS. A generic SDS must not provide less information, in terms of quantity, quality, and details, than individual SDSs for each hazardous product in the series would provide.

If the actual concentration or actual concentration range of an ingredient of a particular hazardous product in the series is different from the actual concentration or actual concentration range disclosed for the rest of the series, either the actual concentration or the actual concentration range must be indicated beside that ingredient under item 3 (Composition/Information on ingredients) of the SDS. Furthermore, if any other specific information element(s) (such as flash point, numerical measure of toxicity, etc.) for a particular hazardous product in the series differs from that of the other products in the series (without affecting the classification), the information element relevant to that hazardous product must be disclosed on the SDS with a statement to indicate to which hazardous product it relates. For example, if one blend of paint uses a yellow-coloured pigment which is more toxic than the pigments used in the other paints in the series, but the blend of paint is still classified in the same hazard class(es) and category(ies) or subcategory(ies) as the other paints in the series, then a note on the generic SDS under item 11 (Toxicological Information) would be required disclosing the additional toxicological information associated with the yellow paint.

The following definitions from the Hazardous Products Act (HPA) apply in this Part of the guidance:

Discussion of paragraph 4(1)(a) of the Hazardous Products Regulations

SDSs are required to have a standardized 16-heading format. The SDS must provide the headings set out in column 1 of Schedule 1 of the HPR, in the order they are presented. The SDS must also include the corresponding item (section) number, which is to be placed immediately before the heading.

For a detailed description of the headings and information elements for SDSs as per Schedule 1 of the HPR, refer to Annex 1 of this guidance.

Discussion of subparagraph 4(1)(b)(i) of the Hazardous Products Regulations

With exceptions outlined under Part 5 of the HPR, all of the specific information elements listed in Column 2 of Schedule 1 of the HPR must be disclosed on the SDS for a hazardous product, if that information is available and applicable. The information required by paragraphs 3(1)(a) and (2)(a) and (d) of Schedule 1 (see below for description) is mandatory and must be provided on the SDS. It is not acceptable to state "not applicable" or "not available" for these items. If any of the information required for paragraphs 3(1)(a) and (2)(a) and (d) of Schedule 1 is the subject of a claim for confidential business information (CBI) under the Hazardous Materials Information Review Act(HMIRA), then replacement information must appear on the SDS (refer to the discussion of section 5.7 of the HPR). There are also further exceptions outlined in sections 5.7, 5.8, and 5.9 of the HPR.

Paragraph 3(1)(a) of Schedule 1 of the HPR – the chemical name of a hazardous product that is a material or substance.

Paragraph 3(2)(a) of Schedule 1 of the HPR - for a hazardous product that is a mixture, the chemical name of each ingredient that, individually, is classified in any category or subcategory of a health hazard class and is present either:

• at or above the corresponding concentration limit or
• at a concentration that results in the mixture being classified in a category or subcategory of any health hazard class

Paragraph 3(2)(d) of Schedule 1 of the HPR - for a hazardous product that is a mixture, the concentration of each ingredient that, individually, is classified in any category or subcategory of a health hazard class and is present either:

• at or above the corresponding concentration limit or
• at a concentration that results in the mixture being classified in a category or subcategory of any health hazard class

The text listed in Column 2 of Schedule 1 (for example, "product identifier", "other means of identification", etc.) is not required to be reproduced on an SDS. However, each item must be addressed either by providing the information or, if the information is not available or not applicable for a particular item (other than items mentioned under paragraphs 3(1)(a) and (2)(a) and (d) of Schedule 1), by indicating that the information is "not available" or "not applicable", whichever is appropriate. Units of measure must be included where applicable.

Note regarding the use of the phrase "Not applicable"

"Not applicable" may only be used in situations where, based on the information available, the specific information element does not apply to the hazardous product. Some examples of situations where certain information elements required under Schedule 1 of the HPR may not be applicable to a particular hazardous product include:

• Under the heading for item 3, Composition/Information on ingredients, information element 3(1)(d), if the hazardous product has no known impurities, stabilizing solvents or stabilizing additives that, individually, are classified in any category or subcategory of a health hazard class and that contribute to the classification of the material or substance, it would be appropriate to indicate that this information element is "not applicable"
• Under the heading for item 9, Physical and chemical properties, information element (h) (flash point), for non-flammable substances such as tetrachloroethylene, methylene chloride or nitrogen, it would be appropriate to indicate that this information element is "not applicable"
• Under the heading for item 10, Stability and reactivity, information element (e) (incompatible materials), if the hazardous product is not reactive with any material, then it would be appropriate to indicate that this information element is "not applicable"

It is important to note that it is misleading to state that the information required by the specific information element is "not applicable" when in fact no data is available. In such cases, the statement "not available" must be used.

As specified in subsections 14.2(2) and (3) of the HPA, suppliers are prohibited from selling or importing a hazardous product that is intended for use, handling or storage in a work place in Canada if the SDS for the hazardous product contains information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included on a label or SDS for that hazardous product.

As an example, it would be considered misleading to state on an SDS that a toxicological end point is "not applicable" when, in fact, there is no data available to assess that end point for that substance. In this case, "not available" should be used.

Also, note that the disclosure of information in accordance with paragraph 4(1)(b) of the HPR is subject to the application of sections 4.4.1 and 4.5 of the HPR regarding concentration ranges (see discussion of section 4.4.1 and discussion of section 4.5 in this guidance).

Discussion of subparagraph 4(1)(b)(ii) of the Hazardous Products Regulations

In the case of a mixture, toxicological information, as required by item 11 of Schedule 1 of the HPR, must be provided for the mixture as a whole. If this information is unavailable for the mixture as a whole, information must be provided for each hazardous ingredient in the mixture, with a clear indication of the chemical name of the hazardous ingredient to which the toxicological information pertains.

Discussion of subparagraphs 4(1)(c)(i) and (ii) of the Hazardous Products Regulations

In addition, the supplier must also disclose, under any applicable heading, all additional hazard information that is available about:

• the hazardous product itself and
• any PMMS that has similar properties, if that information is applicable under normal conditions of use and not redundant to information already provided for the hazardous product itself. This information includes any evidence based on established scientific principles. The additional hazard information regarding the PMMS that has similar properties must be indicated on the SDS alongside an identification of that PMMS.

The intent of paragraph 4(1)(c) is to ensure that any additional hazard information with regard to a hazardous product or a PMMS that has similar properties, that is not already addressed by the information elements specified in Schedule 1 of the HPR, is required to be disclosed on the SDS.

The following are some examples of additional hazard information with regard to a hazardous product that may not be addressed by the information elements specified in Schedule 1 of the HPR:

• In the case of a flammable hazardous product which, upon exposure to heat or a source of ignition, creates a hazardous combustion product, the chemical name of the hazardous combustion product
• In the case of a substance or mixture that, in contact with water, emits a flammable gas, the chemical name of the flammable gas
• In the case of a substance or mixture that, in contact with water, emits a toxic gas, the chemical name of the toxic gas
• The occurrence of known synergistic or antagonistic effects

Discussion of subsection 4(2) of the Hazardous Products Regulations

Subsection 4(2) of the HPR provides that the content of the specific information elements listed under items 12, 13, 14 and 15 of Schedule 1 of the HPR may be omitted.

Therefore, it is acceptable to have an SDS that does not have any content under the following items:

• Item 12: Ecological information
• Item 13: Disposal considerations
• Item 14: Transport information
• Item 15: Regulatory information

However, the item numbers (12 through 15) and the corresponding headings for each of these items must appear on the SDS, sequentially, as indicated in Column 1 of Schedule 1 of the HPR. Even though the specific information elements for these headings may be omitted, if the information is available, it is a good practice to provide it on the SDS as it may be useful to users of SDSs.

Discussion of subsection 4(3) of the Hazardous Products Regulations

This subsection applies to hazardous products that are classified in Biohazardous Infectious Materials (BIM) — Category 1 (Subpart 11 of Part 8 of the HPR), whether they are classified only in this hazard class or in this hazard class as well as 1 or more other physical and/or health hazard classes of the HPR.

The 16-heading SDS format detailed in Schedule 1 of the HPR is intended primarily for hazardous products, mixtures and substances. However, as specified in section 8.11 of the HPR, "biohazardous infectious material" means "any microorganism, nucleic acid or protein that causes or is a probable cause of infection, with or without toxicity, in humans or animals". The headings and specific information elements of the Schedule 1 SDS format do not provide all the necessary and useful information on the properties and hazards associated with BIM. Therefore, Health Canada, in collaboration with the Public Health Agency of Canada (PHAC) developed a 9-heading SDS appendix, as set out in Schedule 2 of the HPR. These additional information elements provide relevant information about which workers handling BIM should be aware. The 9-heading appendix to the SDS is hereafter referred to, in this part of the guidance, as the "BIM SDS appendix" (Annex 2 of this guidance).

The format of the BIM SDS appendix set out in Schedule 2 of the HPR (that is, the headings and their specific information elements) is aligned with the format used in PHAC's Pathogen Safety Data Sheets (PSDSs). PHAC has prepared numerous PSDSs that are publicly available on their website. A supplier who is selling or importing a hazardous product that is classified in BIM — Category 1 (whether classified only in this hazard class or in 1 or more other hazard classes as well) may access the appropriate PSDS from PHAC's website (if PHAC has prepared a PSDS for the BIM in question). The supplier may be able to use the PSDS to fulfill the information requirements set out in subsection 4(3) of the HPR (that is, the Schedule 2 portion of the SDS), but it is important to note that the supplier is always responsible for ensuring that the information on an SDS is accurate, up-to-date, and compliant with the HPR.

The supplier of a hazardous product that is classified in BIM — Category 1 must obtain or prepare an SDS that complies with subsection 4(1) and Schedule 1 of the HPR. Then, the supplier must add the information required by Schedule 2 of the HPR directly below item 16 of the Schedule 1 portion of the SDS to produce the complete SDS that is required for a hazardous product classified in BIM — Category 1. Refer to the section below on SDS requirements for hazardous products that are BIM only for further information.

With regard to the BIM SDS appendix:

1. The BIM SDS appendix must immediately follow the standard 16-heading SDS prepared in accordance with subsection 4(1) and Schedule 1 of the HPR.
2. The headings set out in Schedule 2 are required, in the order they are presented.
3. The name of each specific information element listed in Column 2 of Schedule 2 is required in the BIM SDS appendix, as well as the content related to the information element. An example is shown below.

   Example: Section I of a BIM SDS appendix for Streptococcus pneumoniae
   SECTION I - INFECTIOUS AGENT
   NAME: Streptococcus pneumoniae
   SYNONYM OR CROSS REFERENCE: (information to be added here)
   CHARACTERISTICS: (information to be added here)
   In each section, the subheadings (shown in bold and uppercase in the above example) must be provided on the SDS, as well as the content related to each corresponding specific information element.
   Note that, for the Schedule 1 portion of the SDS, it is not necessary to reproduce the text listed in Column 2 of Schedule 1 of the HPR (for example, "product identifier", "other means of identification", etc.). Only the content related to each specific information element listed in Column 2 of Schedule 1 is required.

4. In the case of each specific information element listed in Column 2 of Schedule 2, either the specified information or an indication that the information is "not available" or "not applicable" must appear on the SDS. This requirement is similar to the requirement set out in subparagraph 4(1)(b)(i) of the HPR.
5. The unit of measure, where applicable, must be included.
6. Repetition of information under multiple headings is not required. This not only applies to information under the headings identified in Schedule 1 and the headings identified in Schedule 2, but also to the information under headings identified in both Schedules 1 and 2. For example, heading 7 of Schedule 1 addresses information relating to "Handling and storage". However, heading 8 of Schedule 2 also addresses information relating to "Handling and storage". Therefore, if, for example, the Schedule 1 portion of the SDS provides accurate and complete information under heading 7, relating to precautions for safe handling and conditions for safe storage, then this information need not be repeated under heading 8 of the BIM SDS appendix (refer to section below on SDS requirements for hazardous products that are BIM only for further information). If the required information is provided under another heading, it is recommended that an indication to this effect be included. For example, if all the required information relating to "Handling and storage" is set out under heading 8 of the Schedule 2 part of the SDS, a statement such as "the required information is found under heading 8 of the appendix to this SDS" is recommended under heading 7 of the Schedule 1 part of the SDS.

For a more detailed description of the headings and specific information elements set out in Schedule 2 of the HPR, refer to Annex 2 of this guidance.

SDS requirements for hazardous products that are biohazardous infectious materials (BIM) only

The guidance provided in this section applies to hazardous products that are only classified in BIM — Category 1 (Subpart 11 of Part 8 of the HPR).

Although there is no specific provision in Part 4 of the HPR regarding hazardous products that are BIM only, it is recognized that some of the specific information elements listed in Column 2 of Schedule 1 may not apply to BIM only products. In addition, other specific information elements that are listed in Column 2 of Schedule 1 may be adequately addressed in the BIM SDS appendix.

For example, heading 8 of Schedule 1 addresses information relating to "Exposure controls/ Personal protection". However, heading 7 of Schedule 2 also addresses information relating to "Exposure controls/Personal protection". As noted above, repetition of information under multiple headings of the SDS for a BIM product is not required.

The following guidance is provided for suppliers that are selling or importing hazardous products intended for use, handling or storage in a work place in Canada that are only classified in BIM — Category 1, in order to make compliance with the SDS requirements less onerous. It is important to note, however, that the supplier is always responsible for ensuring that the information on an SDS is accurate, up-to-date and compliant with the HPR.

With regard to the Schedule 1 portion of the SDS, as shown in Table 4.1 below, some of the specific information elements listed under certain headings of Schedule 1 may be indicated as "not applicable" if they are not applicable to the product or may be omitted if they are already addressed in the BIM SDS appendix. In this case, an indication that the information is found elsewhere in the SDS is recommended. Although not shown in the table below, an indication of "not available" can be used if the information is not available for the product. By extension, no header can appear without any associated information listed under the header, with the exception of items 12 through 15 of the Schedule 1 portion of the SDS.

Table 4.1: Guidance on the requirements for the Schedule 1 portion of the SDS for hazardous products that are BIM only

Schedule 1 Item No.	Schedule 1 Heading	Guidance with regard to content under this Schedule 1 heading for hazardous products that are BIM only (see Notes below)
1	Identification	Although some of this information may already appear in the BIM SDS appendix, it may be the case that items 1(a) through (e) (product identifier, other means of identification, recommend use and restrictions on use, initial supplier identifier and emergency telephone number and restrictions on the use of that number) will need to be addressed in the Schedule 1 part of the SDS.
2	Hazard identification	Items 2(a) (classification of the hazardous product, or, in the case of a hazardous product classified in Physical Hazards Not Otherwise Classified or Health Hazards Not Otherwise Classified, a description of the identified hazard) and (b), (b.1) and (b.2) (symbol, signal word, hazard statement and precautionary statements for each category or subcategory of each hazard class in which the hazardous product is classified), as well as supplemental label elements, if applicable, must be addressed. It is not expected that these items would be adequately addressed by the BIM SDS appendix. However, item 2(c) (other hazards known to the supplier with respect to the hazardous product) may be adequately addressed in the BIM SDS appendix under items 2 (Hazard Identification) and 6 (Laboratory Hazard) of Schedule 2.
3	Composition/Information on ingredients	It may be that some of the specific information elements listed under item 3 (the chemical name(s), common name(s) and synonyms, CAS registry number(s), chemical name of the impurities, stabilizing solvents and additives, and concentration) will be addressed in the BIM SDS appendix under item 1 of Schedule 2 (Infectious Agent). However, any information element listed under item 3 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
4	First-aid measures	It may be that most of the specific information elements listed under item 4 (first-aid measures, symptoms and effects, indication of immediate medical attention and special treatment needed, if necessary) will be addressed in the BIM SDS appendix under item 5 of Schedule 2 (First Aid/Medical). However, any information element listed under item 4 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
5	Fire-fighting measures	It may be that the specific information elements listed under item 5 (extinguishing media, specific hazards arising from the product, special protective equipment and precautions) will not apply to most BIM only products. If this is the case for the BIM only hazardous product in question, then an indication of "not applicable" must appear under this header.
6	Accidental release measures	It may be that most of the specific information elements listed under item 6 (personal precautions, methods and materials for containment and cleaning up) will be addressed in the BIM SDS appendix under items 7 (Exposure Controls/ Personal Protection) and 8 (Handling and Storage) of Schedule 2. However, any information element listed under item 6 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
7	Handling and storage	It may be that most of the specific information elements listed under item 7 (precautions for safe handling, conditions for safe storage) will be addressed in the BIM SDS appendix under item 8 of Schedule 2 (Handling and Storage). However, any information element listed under item 7 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
8	Exposure controls/ Personal protection	It may be that most of the specific information elements listed under item 8 (control parameters, engineering controls, individual protection measures) will be addressed in the BIM SDS appendix under item 7 of Schedule 2 (Exposure Controls/Personal Protection). However, any information element listed under item 8 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
9	Physical and chemical properties	It may be that the specific information elements listed under item 9 of Schedule 1 will not be addressed in the BIM SDS appendix. It is expected that there would be applicable information for paragraphs 9(a), (b) and (c) of Schedule 1 (physical state, colour and odour, respectively) and that therefore information would need to be included to that effect under this header. However, it is possible that items 9(d) through (r) may not be applicable, in which case an indication of "not applicable" must appear.
10	Stability and reactivity	It may be that some of the specific information elements listed under item 10 (stability and reactivity) will be addressed in the BIM SDS appendix under item 4 of Schedule 2 (Stability and Viability). However, any information element listed under item 10 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
11	Toxicological information	It may be that some of the specific information elements listed under item 11 (concise but complete description of the various toxic health effects and the data used to identify those effects) will be addressed in the BIM SDS appendix, for example, under item 2(a) (pathogenicity/toxicity), 6(a) (laboratory-acquired infections), 6(c) (primary hazards), and 6(d) (special hazards) of Schedule 2. However, any information element listed under item 11 of Schedule 1 that is not covered in the BIM SDS appendix must be addressed.
12	Ecological information	As permitted by subsection 4(2) of the HPR, the content of the specific information elements listed under items 12, 13, 14 and 15 may be omitted as long as the item numbers and headings appear on the SDS.
13	Disposal considerations
14	Transport information
15	Regulatory information
16	Other information	Although item 9(b) of Schedule 2 requires the last file update date, if the PSDS from PHAC is used, the date that would be provided there under item 9(b) of the Schedule 2 part of the SDS would be the date of preparation, or update, as applicable, of the PSDS by PHAC. It is important to note, however, that the supplier is always responsible for ensuring that the information taken from PHAC's PSDS is accurate and up-to-date. In addition, the date of preparation, or update, as applicable, of the Schedule 1 portion of the SDS by the supplier is an important piece of information that must also be provided. This information may differ from the date of preparation or update for the BIM SDS appendix.

Discussion of subsection 4(4) of the Hazardous Products Regulations

For a mixture that contains more than 1 BIM, a separate and distinct BIM SDS appendix must be prepared for each BIM in the mixture, in accordance with the format of Schedule 2 of the HPR. It is not acceptable to have only 1 SDS appendix that provides, under each heading, the specific information elements for more than 1 BIM.

Discussion of subsection 4.1(1) of the Hazardous Products Regulations

Subsection 4.1(1) applies to situations in which the instructions for use, provided with a hazardous product, require its combination with 1 or more PMMS. This PMMS may or may not be a hazardous product and may or may not be provided with the hazardous product. If the combination of the hazardous product and the PMMS results in the creation of 1 or more new materials or substances that present a new or more severe hazard that has not already been identified on the SDS, then the SDS must provide information on the hazards of the new material(s) or substance(s). It is important to note that the supplier could provide the instructions for use in any form, such as, on the label, on the SDS or in a written document provided with the product.

This situation could arise, for example, when 2 or more PMMS packaged together in a kit are used in accordance with the instructions for use provided at the time of sale or import. For example, hazardous product ABC is classified in Acute Toxicity (Dermal) — Category 2 and comes with instructions for use, provided at the time of sale or import, which inform the worker to mix it with another product. The result is the formation of a new substance that is classified in Eye Irritation — Category 2. In this example, the SDS of hazardous product ABC must also provide information on the hazards of the new substance, because it presents a new hazard that has not already been identified on the SDS. The same requirement would apply if a hazardous product that is classified in Acute Toxicity (Dermal) — Category 2 comes with instructions for use that involve mixing with another product that may or may not be hazardous, and this results in the formation of a new substance that is classified in Acute Toxicity (Dermal) — Category 1 (a more severe hazard than the hazard presented by the original hazardous product).

Additional hazard information with respect to the new material or substance must be provided on the SDS of the hazardous product for which instructions for use require its combination with 1 or more PMMS. There must be a clear indication on the SDS that the additional information pertains to the new material or substance. First, the nature of the new or more severe hazard must be described (for example: "upon mixing as per the instructions, will emit a new substance classified in Skin Irritation — Category 2"). Secondly, the supplier must address each of the applicable specific information elements for which information is available under the following item numbers and headings of Schedule 1 of the HPR (as specified in subsection 4.1(2) of the HPR, this information may appear anywhere on the SDS):

4. First-aid measures
5. Fire-fighting measures
6. Accidental release measures
7. Handling and storage
8. Exposure controls/Personal protection
9. Physical and chemical properties
10. Stability and reactivity
11. Toxicological information

The supplier is required to provide information on the end material(s) or substance(s) and not on the intermediate material(s) or substance(s) that are formed during the reaction. This provision does not apply to situations where the instructions for use, provided with the hazardous product, require its combination with 1 or more PMMS (hazardous or not) but do not create a new hazardous material or substance which presents a new or more severe hazard.

Products packaged in multi-compartment containers

Multi-compartment products are products that contain at least 2 PMMS in separate compartments (see example in Figure 8 below). The multi-compartment product may be designed either to allow, or not to allow, access to the individual PMMS.

In the case of a multi-compartment product that contains 1 or more hazardous products, each hazardous product must be labelled appropriately and must have a corresponding SDS. Each label must be placed on a surface of the container that makes it obvious to which hazardous product in the multi-compartment container it refers. Either a separate SDS for each individual hazardous product or 1 SDS for all the hazardous products included in the multi-compartment container is acceptable. If the product comes with instructions that involve mixing the components and this mixture results in the formation of a new material or substance that poses a new or more severe hazard, then the provision set out in subsection 4.1(1) of the HPR would apply.

Figure 8 - Text description

A container containing 2 PMMS in separate compartments  

Discussion of subsection 4.1(2) of the Hazardous Products Regulations

The additional information elements required by subsection 4.1(1) of the HPR do not have to appear under items 4 through 11, respectively, of the SDS. Rather, they may appear anywhere on the SDS, as long as the information elements are addressed and there is an indication that the information pertains to the new material or substance that presents 1 or more new or more severe hazards not already identified on the SDS.

Discussion of section 4.2 of the Hazardous Products Regulations

To create a clear link between the label and the SDS of any hazardous product, the product identifier, initial supplier identifier and, if applicable, any replacement information required under subsection 5.7(9) or (10) that are provided on the SDS of the hazardous product must be exactly the same as those that are provided on the product label.

Furthermore, as set out in section 5.8 of the HPR, in a situation where a hazardous product is being sold by a distributor, the distributor may provide their name, address and telephone number on the label and SDS instead of the contact information of the initial supplier. Since the label and SDS must match with regard to the product identifier and the initial supplier identifier, the distributor must replace the initial supplier's information with their information on both the label and the SDS.

Discussion of section 4.3 of the Hazardous Products Regulations

Section 4.3 applies to hazardous products that are mixtures. If the actual concentration or the actual concentration range of an ingredient is expressed as a percentage, the units used to calculate the percentage must be provided.

Examples of the application of section 4.3 include:

• the weight of the ingredient in proportion to the weight of the hazardous product (for example, 9.85% weight/weight);
• the volume of the ingredient in proportion to the volume of the hazardous product (for example, 1.7% volume/volume); or
• the weight of the ingredient in proportion to the volume of the hazardous product (for example, 0.463% weight/volume).

Alternatively, the concentration of a material or substance in a hazardous product may be expressed using metric units of measurement (for example, 4.63 g/l, which is equivalent to 0.463% weight/volume). Note, the HPR does not prohibit the use of units in other systems such as the imperial system.

Discussion of section 4.4 of the Hazardous Products Regulations

For ingredients that are present in a range of concentrations in a mixture, the information provided on the SDS must correspond to the available data that reflects the most hazardous concentration of each hazardous ingredient in the mixture, whether those data pertain to the hazardous ingredient itself or to the mixture as a whole. For example, if a mixture contains a concentration of the hazardous ingredient A, which is present in a range of concentrations between 7 to 9.6%, the information provided on the SDS must be based on 9.6%, if this is the most hazardous concentration of ingredient A. In most situations, the most hazardous concentration will be the highest value in the concentration range. If the highest concentration in the range is not the most hazardous, then the information provided on the SDS must be based on the concentration that is the most hazardous. In the event where there is available data on the mixture as a whole and this data is based on tests performed on the mixture, the supplier must ensure that the ingredients in the tested mixture were present in their most hazardous concentration within their respective ranges.

This requirement also applies when a prescribed concentration range is used in accordance with section 4.5 of the HPR (refer to discussion of section 4.5 of the HPR). For example, where the actual concentration range of ingredient B varies from 4 to 6%, the supplier may choose to withhold the actual concentration range of that ingredient as a trade secret and instead use the prescribed concentration range of 3 to 7% (paragraph 4.5(3)(d)). In this case, the information provided on the SDS must be based on the actual maximum concentration of 6%, not 7%, if this is the most hazardous concentration of ingredient B. If the highest concentration in the actual concentration range is not the most hazardous, then the information provided on the SDS must be based on the concentration that is the most hazardous in the actual concentration range of 4 to 6%.

Discussion of subsection 4.4.1(1) of the Hazardous Products Regulations

Subsection 4.4.1(1) of the HPR outlines the requirements to disclose either the actual concentration or a concentration range, for a material or substance in a hazardous product, when it is required to be provided on an SDS and the material or substance is always present at the same concentration.

Paragraph 4.4.1(1)(a) of the HPR requires that when a material or substance in a hazardous product is required to be disclosed and it is always present at the same concentration, the SDS must disclose the actual concentration of the material or substance in the hazardous product.

However, paragraphs 4.4.1(1)(b) and (c) allow a prescribed concentration range, or a concentration range that falls entirely within 1 of the prescribed ranges, to be provided on the SDS in lieu of the actual concentration of the material or substance, if the actual concentration is withheld as a trade secret. The prescribed concentration ranges are set out in subsection 4.4.1(3) of the HPR. In a situation where paragraph 4.4.1(b) or (c) is applied, the actual concentration of the material or substance in the hazardous product must fall within the disclosed concentration range. Furthermore, where paragraph 4.4.1(b) or (c) is applied, as specified in subsection 4.4.1(4), a statement to the effect that the actual concentration is withheld as a trade secret is required on the SDS, immediately following the disclosed concentration range.

Discussion of subsection 4.4.1(2) of the Hazardous Products Regulations

If the actual concentration of a material or substance falls within more than 1 of the prescribed concentration ranges set out under subsection 4.4.1(3), then any one of those prescribed concentration ranges or a range that falls entirely within any one of those ranges may be used on the SDS. As specified in subsection 4.4.1(4), a statement to the effect that the actual concentration is withheld as a trade secret is required on the SDS, immediately following the disclosed concentration range.

For example, if the actual concentration of hazardous ingredient A in a mixture is 1.2%, and therefore falls within the prescribed concentration ranges of 0.5 to 1.5% (paragraph 4.4.1(3)(b)) and 1 to 5% (paragraph 4.4.1(3)(c)), then either 0.5 to 1.5% or 1 to 5% can be provided on the SDS. Alternatively, a range that falls entirely within either one of those ranges, for example, 1 to 2%, may be provided on the SDS, as long as the actual concentration falls within the disclosed concentration range.

Discussion of subsection 4.4.1(3) of the Hazardous Products Regulations

If, for the purpose of protecting a trade secret, a prescribed concentration range is provided on the SDS instead of the actual concentration of a material or substance, 1 of the ranges set out under subsection 4.4.1(3) can be used on the SDS.

A concentration range that falls entirely within any of those prescribed ranges may also be used, as long as the actual concentration of the material or substance falls within the disclosed concentration range. For example, if the actual concentration of hazardous ingredient B in a mixture is 70% and therefore falls within the prescribed concentration range of 60 to 80% (paragraph 4.4.1(3)(k)), a range that is narrower than 60 to 80%, such as 65 to 75%, can be used on the SDS.

In a situation where 1 of the prescribed concentration ranges or a range that falls entirely within any of those prescribed ranges is used on the SDS, a statement to the effect that the actual concentration is withheld as a trade secret is required, immediately following the disclosed concentration range (as specified in subsection 4.4.1(4)).

If there is evidence that an ingredient present at a concentration less than 0.1% contributes to a product being classified in a category or subcategory of any health hazard class, then the ingredient and its concentration must be disclosed on the SDS (refer to the discussion of subsection 2.5(1), Part 8 in this guidance and Schedule 1 of the HPR). However, if the actual concentration is less than 0.1% and is considered to be a trade secret, the only way to protect this information is to file a claim for exemption under the HMIRA (refer to Appendix A and the Guide for using the claim for exemption online application form for workplace hazardous products), as there are no prescribed concentration ranges for less than 0.1%.

Discussion of subsection 4.4.1(4) of the Hazardous Products Regulations

If the SDS provides a prescribed concentration range or a range that falls entirely within 1 of the prescribed concentration ranges, in order to protect the actual concentration of the material or substance as a trade secret, a claim for exemption under the HMIRA does not need to be filed. A statement to the effect that the actual concentration is withheld as a trade secret must be provided on the SDS immediately following the disclosed concentration range. The expression "immediately following" could include the placement of an asterisk beside the disclosed concentration range that refers to a statement at the end of the list of ingredients.

Discussion of subsection 4.5(1) of the Hazardous Products Regulations

Subsection 4.5(1) of the HPR outlines the requirements to disclose either the actual concentration range or a prescribed concentration range, for a material or substance in a hazardous product, when it is required to be provided on an SDS and the material or substance is not always present at the same concentration. The concentration of a hazardous ingredient in a mixture may vary due to batch-to-batch variability (refer to the discussion of subsection 2.3(1) of the HPR for a discussion of this term). Maintaining documentation on the manufacturing process which demonstrates product composition variability is important to support the disclosure of any actual concentration range.

Paragraph 4.5(1)(a) of the HPR requires that when a material or substance in a hazardous product is required to be disclosed but it is not always present at the same concentration, the SDS must disclose the actual concentration range of the material or substance in the hazardous product. For example, if the manufacturing formula for a mixture calls for 10% of hazardous ingredient A, but due to batch-to-batch variability, the actual concentration is expected to vary from 8 to 12%, where an actual concentration range is used, then the SDS must indicate 8 to 12% as the actual concentration range of ingredient A. This requirement applies regardless of the magnitude of the actual concentration range.

However, paragraphs 4.5(1)(b) and (b.1) allow a prescribed concentration range, or a concentration range that falls entirely within 1 of those prescribed ranges, to be provided on the SDS in lieu of the actual concentration range, if the actual concentration range is a trade secret. The prescribed concentration ranges can be found in subsection 4.5(3) of the HPR.

Alternatively, as specified in paragraph 4.5(1)(c), if the actual concentration range does not fall entirely within a prescribed concentration range and the actual concentration range of the hazardous ingredient in the hazardous product is equal to or greater than 0.1% but less than or equal to 30%, a concentration range can be created by combining 2 consecutive prescribed concentration ranges. The combined concentration range can only be provided if it was not formed with a prescribed concentration range that falls entirely outside of the actual concentration range.

Prescribed concentration ranges are considered to be consecutive based on the order in which they are listed in the HPR (for example, paragraphs 4.5(3)(a) + (3)(b), paragraphs 4.5(3)(b) + (3)(c) or paragraphs 4.5(3)(c) + (3)(d) of the HPR). When combining consecutive prescribed concentration ranges, the most lower bound and upper bound concentrations must be used to form the combined range. For example, if the actual concentration range of hazardous ingredient A is 2.5 to 5.5%, the prescribed concentration ranges of 1 to 5% (paragraph 4.5(3)(c)) and 3 to 7% (paragraph 4.5(3)(d)) can be combined to create a combined concentration range of 1 to 7% for hazardous ingredient A.

If the actual concentration range of a hazardous ingredient spans over more than 2 consecutive prescribed concentration ranges, there are 2 options: either submit a claim for exemption under the HMIRA (refer to Appendix A and the Guide for using the claim for exemption online application form for workplace hazardous products), or provide the actual concentration range on the SDS. For example, if the actual concentration range is 4 to 18% and is a trade secret, for the purpose of protecting the trade secret a claim for exemption would need to be filed under the HMIRA.

In a situation where paragraph 4.5(1)(b), (b.1) or (c) is applied, the actual concentration range of the material or substance in the hazardous product must fall entirely within the disclosed concentration range. Furthermore, where paragraph 4.5(1)(b), (b.1) or (c) is applied, and, as specified in subsection 4.5(4), a statement to the effect that the actual concentration range is withheld as a trade secret is required on the SDS, immediately following the disclosed concentration range.

When an actual concentration range, prescribed concentration range, or a concentration range that falls entirely within a prescribed concentration range is disclosed, SDSs must be in compliance with requirements in the HPR for hazard classification (section 2.6) and information disclosed on SDSs (section 4.4) (refer to the discussion of section 2.6 of the HPR and the discussion of section 4.4 of the HPR).

Discussion of subsection 4.5(2) of the Hazardous Products Regulations

If the actual concentration range of a hazardous ingredient falls entirely within more than 1 of the prescribed concentration ranges set out in subsection 4.5(3), any one of those prescribed concentration ranges or a range that falls entirely within any one of those prescribed ranges may be provided on the SDS for the purpose of protecting a trade secret. As specified in subsection 4.5(4), a statement to the effect that the actual concentration range is withheld as a trade secret is required on the SDS, immediately following the disclosed concentration range.

For example, if the actual concentration range of hazardous ingredient A in a mixture is 30 to 40%, and therefore falls within the prescribed concentration ranges of 15 to 40% (paragraph 4.5(3)(h)) and 30 to 60% (paragraph 4.5(3)(i)), then either 15 to 40% or 30 to 60% may be provided on the SDS. Alternatively, a range that falls entirely within either one of those ranges, for example, 30 to 45%, may be provided on the SDS, as long as the actual concentration range falls entirely within the disclosed concentration range.

Discussion of subsection 4.5(3) of the Hazardous Products Regulations

If, for the purpose of protecting a trade secret, a prescribed concentration range is provided on the SDS instead of the actual concentration range of a hazardous ingredient, the ranges provided under subsection 4.5(3) may be used on the SDS.

A concentration range that falls entirely within any of those prescribed ranges may also be used. For example, if the actual concentration range of hazardous ingredient B in a mixture is 70 to 75% and therefore falls within the prescribed concentration range of 60 to 80% (paragraph 4.5(3)(k)), a range that is narrower than 60 to 80%, such as 65 to 75%, may be used on the SDS, as long as the actual concentration range falls entirely within the concentration range provided on the SDS.

If there is evidence that an ingredient present at a concentration less than 0.1% contributes to a product being classified in a category or subcategory of any health hazard class, then the ingredient and its concentration must be disclosed on the SDS (refer to the discussion of subsection 2.5(1) of the HPR, Part 8 and Schedule 1 of the HPR). However, if the ingredient is not always present at the same concentration and its actual concentration range spans less than 0.1% and is considered to be a trade secret, the only way to protect this information is to file a claim for exemption under the HMIRA (refer to Appendix A and the Guide for using the claim for exemption online application form for workplace hazardous products), as there are no prescribed concentration ranges for less than 0.1%.

Discussion of subsection 4.5(4) of the Hazardous Products Regulations

If the SDS provides a prescribed concentration range or a range that falls entirely within 1 of the prescribed concentration ranges, in order to protect the actual concentration range as a trade secret, a statement to the effect that the actual concentration range is withheld as a trade secret must be provided on the SDS. The expression "immediately following" could include the placement of an asterisk beside the prescribed concentration range that refers to a statement at the end of the list of ingredients.

Discussion of section 4.6 of the Hazardous Products Regulations

Precautionary statements may be combined on the SDS if the combination contains the same information as would have been conveyed by each of the individual precautionary statements. For example, "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking."; "Store in a well-ventilated place."; and "Keep cool." may be combined to read: "Keep cool, in a well-ventilated place, away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking".

The precautionary statements required to be on the SDS may not apply in certain circumstances. If a precautionary statement is not applicable with regard to the normal conditions of use, handling and storage of the hazardous product, it may be omitted from the SDS.

Hazard statements required to be provided on the SDS may be combined where appropriate, if the combination conveys the same information as would have been conveyed by each of the individual statements. For example, "Fatal if swallowed" and "Fatal if inhaled" may be combined to read "Fatal if swallowed or if inhaled".

Discussion of section 4.7 of the Hazardous Products Regulations

Section 4.7 of the HPR is intended to reduce the amount of information required to be displayed on the SDS. Under the specified conditions, outlined in detail below, if a more severe symbol, signal word and/or hazard statement are required to be disclosed, there is no requirement to also disclose the less severe symbol, signal word and/or hazard statement.

• If the signal word "Danger" is required on the SDS, the signal word "Warning" is not required.
• If the hazard statement "Causes severe skin burns and eye damage" is required on the SDS, any requirement to provide the hazard statement "Causes serious eye damage" does not apply.
• Hazardous products classified in Acute Toxicity (Inhalation) — Category 1, 2, 3 or 4 further to subsection 8.1.1(2) of the HPR are not required to have the GHS-prescribed hazard statement, namely, "Fatal/toxic/harmful if inhaled" on their SDSs. However, as specified in paragraph 3(1)(g) and item 2(b) of Schedule 1 of the HPR, the following supplemental hazard statement is required: "In contact with water, releases gases which are fatal/toxic/harmful if inhaled". "Fatal" is required for hazardous products that release a gaseous substance that is classified in Category 1 or 2. "Toxic" is required for hazardous products that release a gaseous substance that is classified in Category 3. "Harmful" is required for hazardous products that release a gaseous substance that is classified in Category 4.
• If the symbol "skull and crossbones" is required on the SDS, the "exclamation mark" to indicate acute toxicity is not required.
• If the symbol "corrosion" is required on the SDS, the "exclamation mark" to indicate skin or eye irritation is not required.
• If the "health hazard" symbol is required to indicate respiratory sensitization, the symbol "exclamation mark" to indicate skin sensitization or skin or eye irritation is not required.

The provisions set out in section 4.7 are exemptions from certain requirements in the HPR. These exemptions are optional and are not mandatory requirements. For example, if a hazardous product is classified as both a respiratory sensitizer and a skin irritant, the supplier may choose to only provide the health hazard symbol, or may include both the health hazard symbol and the exclamation mark symbol on the label and SDS.

In a situation where an exemption could be applied, if the supplier instead decides to comply with the full suite of standard requirements of the HPR, provision of the full suite of requirements is acceptable and in compliance with the HPR.

References for this section of the guidance (Hazardous Products Regulations: Part 4 Safety data sheet)

• Hazardous Materials Information Review Act, R.S.C. 1985, c. 24 (3rd Supp.), Part III
• Hazardous Products Act, R.S.C., 1985, c. H-3
• Hazardous Products Regulations, SOR/2015-17
• United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Seventh revised edition, 2017.

Annex 1– Information elements on safety data sheet – Schedule 1 of the HPR

Additional guidance on the preparation of safety data sheets (SDSs) is found in Annex 4 of the Globally Harmonized System of Classification and Labelling of Chemicals, Seventh Revised Edition (GHS).

Note: In the case of any discrepancy between Annex 4 of the GHS and either this guidance or the Hazardous Products Regulations (HPR), this guidance or the HPR, as the case may be, shall prevail.

Making cross-references between sections on an SDS for products that are not classified in the biohazardous infectious materials (BIM) hazard class

As required under paragraph 4(1)(b) of the HPR, the content of specific information elements must be provided in each section of the SDS. As such, each section of the SDS must provide the required information, with the exception of the content of the specific information elements in sections 12 to 15 of the SDS, which may be omitted in accordance with subsection 4(2) of the HPR. Cross-references are permitted to indicate related information found in other sections of the SDS, as long as the content of the specific information element is provided in the section that makes a cross-reference to another section. A best practice to ensure that the cross-reference is clear is to indicate specifically what information can be found, and in which section of the SDS. This approach ensures that all required information is present in the correct section of the SDS, as required by the HPR, and it provides clarity for a user of the SDS by identifying where important related information can be found on the SDS.

It is important to note that if a cross-reference is included on an SDS, it cannot provide or consist of information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included in a label or SDS for that hazardous product. This is prohibited under section 14.2 of the Hazardous Products Act (HPA). Some examples of acceptable and unacceptable cross-referencing for hazardous products that are not classified in the BIM hazard class are provided under item 4 (First-aid Measures), item 6 (Accidental Release Measures), and item 7 (Handling and Storage) of this Annex.

For more information on SDS requirements for hazardous products that are classified in the BIM hazard class, including cross-referencing, refer to the discussion of subsection 4(3) and the discussion of subsection 4(4) of the HPR, in Part 4 and Annex 2 of this guidance.

Information not available or not applicable

If any of the information, except that outlined under item 3(1)(a) and item (2)(a) and (d) of Schedule 1, is not available or not applicable, an indication to that effect must be clearly stated on the SDS in lieu of the required specific information element. Despite this, the content of the specific information elements for items 12 to 15 of Schedule 1 may be omitted from the SDS.

Item 1 : Identification: The required information in this section consists of:

• The product identifier used on the label (the brand name, chemical name, common name, generic name or trade name of the product)
• Other means of identification of the product (any other common names or synonyms by which the product is commonly known)
  • A long list of common names and synonyms is not necessary
• The recommended use of the product (a brief description of what the product actually does, such as "flame retardant") and any restrictions on its use
• The initial supplier identifier (the full name, address and telephone number of the Canadian manufacturer or the Canadian importer of the hazardous product)
  • The term "manufacturer" is defined in subsection 1(1) of the HPR as "a supplier, who in the course of business in Canada, manufactures, produces, processes, packages or labels a hazardous product and sells it"
  • The term "Canadian importer" means the person who, in the course of business in Canada, is responsible for importing the hazardous product into Canada
• An emergency telephone number and any restrictions on the use of that number (for example, days and hours of operation), if applicable
  • The emergency telephone number is a telephone number that will enable a caller to obtain information regarding the hazardous product.
  • It does not have to be a Canadian telephone number
  • If the language spoken at the emergency telephone number is neither English nor French, this should be indicated on the SDS as part of the restrictions on the use of the number
  • It is important to note that a Canadian Transport Emergency Centre (CANUTEC) telephone number must not be listed as the emergency telephone number
    • The overall mandate of CANUTEC is to promote public safety in the transportation of dangerous goods by all modes CANUTEC cannot provide any information on the storage, use or handling of hazardous products
  • If a telephone number is available that can serve as an emergency telephone number, it must be disclosed
  • If no emergency telephone number is available, the expression "not available" or an indication to that effect must be provided, in accordance with subparagraph 4(1)(b)(i) of the HPR

With regard to the address that must be provided as part of the initial supplier identifier, this may be any valid Canadian postal address such as a full street address of the premises of the supplier or a post office box number with the address of the post office. A Canadian distributor may provide their contact information in lieu of the initial supplier identifier. For further information about this exception, refer to the discussion of section 5.8 of the HPR.

Under the HPR, a distributor who buys a hazardous product, re-labels the product and then sells that product, is considered to be a manufacturer and the initial supplier of the hazardous product. In this situation, the Canadian distributor must provide their name, address and telephone number on the label and SDS.

If a hazardous product is being imported only for use in the importer's own work place, the Canadian importer may retain the name, address and telephone number of the foreign supplier on the SDS instead of replacing it with their own contact information. This is the only situation in which a hazardous product, which is intended for use, handling or storage in a Canadian work place, may be imported into Canada with only the name, address and telephone number of a foreign supplier on the SDS. For further information, refer to the discussion of section 5.9 of the HPR.

If a hazardous product is being imported into Canada, but is not intended for exclusive use in the importer's work place, the Canadian importer's (that is, the Canadian party who is responsible for bringing the hazardous product into Canada) name, address and telephone number must be provided on the SDS. The Canadian importer is responsible for ensuring that the importation of the hazardous product complies with the requirements of the HPA and the HPR (for example, labeling and SDS requirements).

It would be acceptable for the SDS to include the contact information of both the Canadian importer and the foreign-based supplier. Additional information may be included on the SDS, as long as the information is not false or misleading (section 14.2 of the HPA prohibits information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included in a label or SDS for a hazardous product).

Item 2 : Hazard identification: This section identifies the hazards of the product and the information associated with those hazards. The required information consists of:

• The hazard classification of the product (for example, Flammable Liquid — Category 1)
• The symbol(s) (if applicable)
• Signal word (if applicable)
• Hazard statement(s)
• Precautionary statements
• Supplemental label elements, if applicable, as specified in paragraphs 3(1)(e) to (g) of the HPR
• Description of any other hazards known to the supplier which did not result in classification (for example, electrical conductance, radioactivity)

Classification of the hazardous product:

Paragraph 2(a) of Schedule 1 of the HPR specifies that, for hazardous products classified in any HPR hazard class other than Physical Hazards Not Otherwise Classified (PHNOC) and Health Hazards Not Otherwise Classified (HHNOC) (Subpart 20 of Part 7 and Subpart 12 of Part 8 of the HPR, respectively), the SDS may disclose either:

• the exact name of the hazard class (as it appears in the HPR), along with the category or subcategory in which the hazardous product is classified, or
• a substantive equivalent of the hazard class name, along with the category or subcategory in which the hazardous product is classified

Abbreviations and acronyms must not be used for the hazard classifications as they are not considered to be substantive equivalents. For example, if the hazardous product is classified in "Specific Target Organ Toxicity — Single Exposure — Category 1", the full name of the hazard classification must be provided on the SDS, and not the acronym "STOT-SE — Category 1".

The allowance for a substantive equivalent of the hazard class name recognizes that, in the U.S. Hazard Communication Standard (HCS), some hazard classes have a slightly different name. For example, if a hazardous product is classified in Self-Reactive Substances and Mixtures — Type B under the HPR, it would be acceptable to instead disclose "Self-Reactive Chemicals — Type B" under section 2 of the SDS, since the HCS refers to "Self-Reactive Chemicals".

For hazardous products classified in PHNOC or HHNOC, the SDS must disclose either the classification (for example, Health Hazards Not Otherwise Classified — Category 1) or a description of the identified hazard. This allowance for using a description of the hazard in lieu of the hazard class name is aligned with the HCS, which requires a description of "any hazards not otherwise classified that have been identified during the classification process" (item 2(d) of Table D.1 of the HCS).

Information elements:

For hazardous products classified in 1 or more of the hazard classes set out in Subparts 2 to 16 and 21 of Part 7 and Subparts 1 to 10 of Part 8 of the HPR, information elements are specified in section 3 of Annex 3 of the GHS for each category or subcategory of each hazard class in which the hazardous product is classified (paragraph 2(b) of Schedule 1 of the HPR). This requirement is subject to subsections 3(2) and (4) to (5) of the HPR. For further information, see the discussion of subsections 3(2) and (4) to (5) of the HPR. The required information elements are:

• Symbol – either the name of the symbol (for example, skull and crossbones, flame) or the symbol itself may be used
  • The names of the symbols are set out in Column 1 of Schedule 3 of the HPR. Note that the pictogram(s) may be used instead of the symbol(s). As outlined in subsection 4.7(4) of the HPR, under specified conditions, if a more severe symbol is required to be provided, there is no need to also provide a less severe symbol.
• Signal word – if there is a requirement to provide the signal word "Danger", any requirement to provide "Warning" does not apply (refer to subsection 4.7(1) of the HPR)
• Hazard statements – may be combined where appropriate (refer to subsection 4.6(3) of the HPR). For example, "Fatal if swallowed" and "Fatal if inhaled" may be combined to read "Fatal if swallowed or if inhaled".
  • For the hazard statements specified in the GHS, if there is text presented in italics, this information should be provided as part of the hazard statement when the information is known. For example, as indicated in section 3 of Annex 3 of the GHS, the hazard statement "causes damage to organs (or state all organs affected, if known) through prolonged or repeated exposure (state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard)" is required for Specific Target Organ Toxicity — Repeated Exposure — Categories 1 and 2. The text in italics should be replaced with the information if known. However, if this information is not known, the text in italics should not be used.
• Precautionary statements – may be combined or omitted where appropriate (refer to subsections 4.6(1) and 4.6(2) of the HPR).
  • An example of a combined precautionary statement would be the following: "Keep away from heat, hot surfaces, sparks, open flames and other ignition sources."; "No smoking."; "Store in a well-ventilated place."; and "Keep cool." may be combined to read: "Keep cool, in a well-ventilated place, away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking".
  • The structure of the precautionary statements specified in the GHS includes text in bold that forms the core part of the precautionary statement.
  • When a forward slash or diagonal mark "/" appears in a precautionary statement text, it indicates that a choice needs to be made between the phrases they separate. In such cases, the supplier must choose the appropriate phrase(s). For example, the precautionary statement P280 "Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…" could read "Wear eye and face protection".
  • When 3 full stops "…" appears in a precautionary statement, they indicate that all applicable conditions are not listed, and the supplier can provide further information. For example, in the statement P241 "Use explosion-proof [electrical/ventilating/lighting/…] equipment", the 3 full stops indicate that other equipment may need to be specified.
  • Where square brackets appear around some text, this indicates that the text in square brackets is not appropriate in every case and should be used only in certain circumstances. In these cases, additional conditions for use explaining when the text should be used is provided in the GHS. For example, P284 "[In case of inadequate ventilation] wear respiratory protection", the conditions of use given with the text include "text in square brackets may be used if additional information is provided with the chemical at the point of use that explains what type of ventilation would be adequate for safe use". Therefore, in this example, if additional information is provided explaining what type of ventilation would be adequate for safe use, the text in square brackets may be used, and the precautionary statement would read "In case of inadequate ventilation wear respiratory protection". However, if the chemical is supplied without additional information on ventilation, the text in square brackets should not be used, and the precautionary statement should read "Wear respiratory protection".
  • Minor variations in the wording of precautionary statements that do not affect the intended meaning of the statements are acceptable. For example, if precautionary statement P233, "Keep container tightly closed", is required and the SDS includes the statement "Keep container securely closed", this would be considered acceptable. As another example, if precautionary statement P351 "Rinse cautiously with water for several minutes", is required and the SDS includes the statement "Rinse cautiously with water", this would not be considered acceptable as it does not convey the same meaning as statement P351.

Note that the hazard and precautionary statement codes in the GHS are intended to be used for reference purposes. The code is not part of the statement and must not be used to replace the statement on the SDS.

For hazardous products that are classified in Combustible Dusts, Simple Asphyxiants, PHNOC, BIM and HHNOC, the information elements are specified in Schedule 5 of the HPR, namely the symbol, signal word and hazard statement (subparagraph 2(b.1)(i) of Schedule 1 of the HPR). In addition, any precautionary statements applicable to the hazardous product in terms of general, prevention, response, storage and disposal precautionary statements are required to be provided on the SDS (subparagraph 2(b.1)(ii) of Schedule 1 of the HPR).

Supplemental label elements:

In accordance with paragraph 2(b.2) of Schedule 1 of the HPR, the SDS for certain hazardous products must include the following supplemental label elements:

• Mixtures classified in the Acute Toxicity hazard class that are classified based on ingredient(s) for which the acute toxicity is known and that contain ingredients of unknown acute toxicity require a supplemental statement indicating what total percentage of the mixture consists of ingredients of unknown acute toxicity. The route of exposure should be included in the statement. Further guidance is provided in the discussion of paragraph 3(1)(e) of the HPR.
• Products classified in the Acute Toxicity hazard class that, in contact with water, release a toxic gaseous substance that has an LC₅₀ that falls into 1 of the ranges indicated in Table 3 to subsection 8.1.1(3) of the HPR, require a supplemental label element consisting of a hazard statement. These products are also referred to as Water-Activated Toxicants. Further guidance is provided in the discussion of paragraph 3(1)(f) of the HPR.
• Products that meet the criteria set out in subsection 8.1.1(2) of the HPR and that are classified, accordingly, in Acute Toxicity (Inhalation) ─ Category 1, 2, 3 or 4 require a supplemental label element consisting of a hazard statement. In the absence of contact with water, these products do not present an acute toxicity hazard based on the available data; however, upon contact with water, these products release a toxic gaseous substance. Therefore, these products are also referred to as Water-Activated Toxicants. Further guidance is provided in the discussion of paragraph 3(1)(g) of the HPR.

Other hazards:

A description of other hazards that may contribute to the overall hazards of the product, but do not result in classification, must be provided on the SDS. For example, if the supplier knows that under normal conditions of use, a hazardous product would be handled in such a manner that its physical form or chemical structure would change and that would create new or more severe hazards, this information must be disclosed under section 2 of the SDS, as per paragraph 2(c) of Schedule 1 of the HPR.

Item 3 Composition/Information on ingredients: This section identifies the hazardous material(s) or substance(s), including impurities, stabilizing solvents and stabilizing additives, contained in a hazardous product. The required information consists of the following information.

For a hazardous product that is a substance or material:

• Chemical name*
• Common name and synonyms*
• Chemical Abstracts Service (CAS) registry number and any unique identifiers*
• The chemical name of the impurities, stabilizing solvents and stabilizing additives known to the supplier, that individually are classified in any health hazard class and that contribute to the classification of the material or substance*

* Unless the information is exempted from disclosure in accordance with the Hazardous Materials Information Review Act (HMIRA) (refer to Appendix A and the Guide for using the claim for exemption online application form for workplace hazardous products). In this case, replacement information must appear on the SDS (refer to the discussion of section 5.7 of the HPR).

The requirement to disclose common names and synonyms for the substance or material includes the obligation to disclose other names by which the substance or material is commonly known in the work place. A long list of common names and synonyms is not necessary.

For a hazardous product that is a mixture:

The following information is required for each material or substance in the mixture that is individually classified in any health hazard class and is present above the concentration limit that is designated for the category or subcategory of the health hazard class in which it is classified – regardless of whether the ingredient contributes to the classification of the mixture as a hazardous product – or is present in the mixture at a concentration that results in the mixture being classified in any health hazard class:

• Chemical name
• Common name and synonyms
• CAS registry number and any unique identifiers
• Concentration

Unless the information is exempted from disclosure in accordance with the HMIRA (refer to Appendix A and the Guide for using the claim for exemption online application form for workplace hazardous products). In this case, replacement information must appear (refer to the discussion of section 5.7 of the HPR).

In a situation where subsection 2.5(2) of the HPR (Concentration limits — equivalent or higher concentration) has been applied with respect to the classification of a mixture that has been determined to be a hazardous product, any ingredient that has been determined not to present the associated hazard in the mixture is still required to be disclosed under item 3 of the SDS, even though this ingredient does not contribute to the classification of the mixture as a hazardous product (refer to the discussion of subsection 2.5(2) of the HPR in Part 2 of this guidance).

The requirement to disclose common names and synonyms for each hazardous ingredient includes the obligation to disclose other names by which the ingredients are commonly known in the work place. A long list of common names and synonyms is not necessary.

If the concentration of an ingredient is expressed as a percentage, the units used to calculate the percentage must be provided, as required by section 4.3 of the HPR. For the ingredients that are present in a range of concentrations in a mixture, the information provided on the SDS must correspond to the data available for the most hazardous concentration of each ingredient, as required by section 4.4 of the HPR.

Sections 4.4.1 and 4.5 of the HPR set out provisions that where there is a requirement to disclose an ingredient's concentration, the SDS must disclose the actual concentration or actual concentration range of an ingredient in a mixture, or a prescribed concentration range, or a concentration range that falls entirely within 1 of the prescribed ranges, or a combined prescribed concentration range (refer to the discussion of sections 4.4.1 and 4.5 of the HPR).

It is possible for a single SDS to provide information on the concentrations or concentration ranges of different ingredients by disclosing both of the following: (i) actual concentrations or actual concentration ranges; and (ii) prescribed concentration ranges and/or ranges that fall entirely within 1 of the prescribed ranges, and/or combined prescribed concentration ranges. In the second situation, for each prescribed concentration range, each range that falls entirely within 1 of the prescribed ranges, and each combined prescribed concentration range, there must be a statement to the effect that the actual concentration or actual concentration range is withheld as a trade secret, immediately following the disclosed range. The expression "immediately following" could include the placement of an asterisk beside the disclosed concentration range that refers to a statement at the end of the list of ingredients.

Item 4 : First-aid measures: This section describes the initial care that should be given to an individual who has been exposed to the product. The required information consists of:

• A description of necessary first aid measures, subdivided according to the different routes of exposure, that is, inhalation, skin and eye contact, and ingestion
  • The recommended first-aid responses provided must be consistent with the classified hazards of the product and the description of the various toxic health effects provided in items 2 and 11 of the SDS, respectively
• A description of the most important symptoms and effects, whether acute or delayed
  • The symptoms and effects must be consistent with the classified hazards of the product and the toxic health effects provided in items 2 and 11 of the SDS, respectively
• An indication of immediate medical attention and special treatment needed, if necessary (for example, known antidotes and any contraindications)

An example of acceptable cross-referencing under item 4 would be the following statement: "The most important symptoms and effects are eye irritation, including redness, watering, pain or itching. For further symptoms and effects, see Section 11 Toxicological Information". This would be acceptable because section 4 of the SDS provides the content of the information element "the most important symptoms and effects, whether acute or delayed", as required by paragraph 4(b) of Schedule 1 of the HPR. In this case, the cross-reference to section 11 provides additional information on other symptoms and effects.

An example of unacceptable cross-referencing would be not listing any symptoms under item 4 and including a statement indicating that "the most important known symptoms and effects are described in Section 11". This would not be acceptable because the content of the required information element "the most important symptoms and effects, whether acute or delayed" is not provided in section 4 of the SDS. In this case, the cross-reference to section 11 is provided in place of providing the information in section 4.

Item 5 : Fire-fighting measures: This section provides information for fighting a fire caused by the product, or that occurs in the vicinity of the product. The required information consists of:

• Suitable and unsuitable extinguishing media. That is, information about extinguishing media that are appropriate and those that are not appropriate for a particular situation involving the hazardous product. Both are required, if available and applicable.
• Specific hazards that may arise as a result of a fire caused by or involving the product, such as the nature of any hazardous combustion products
  • Information on the nature of the hazardous combustion products (for example, these substances may be flammable, toxic, reactive and/or have other hazards) must be included on the SDS if available, as this would provide more specific and detailed information to the reader
• Special protective equipment and precautions for fire-fighters

Item 6 : Accidental release measures: This section provides information on the appropriate response to spills, leaks, or releases, including containment and clean-up practices to prevent or minimize exposure to and adverse effects on people, property, or the environment. This information includes distinction between responses to large and small spills, if the spill volume has a significant impact on the hazard. The required information consists of:

• Description of personal precautions (such as removal of ignition sources or providing sufficient ventilation) and protective equipment to prevent the hazardous product from coming into contact with skin, eyes, and clothing
• Description of emergency procedures, including instructions for evacuations, consulting experts when needed, and appropriate protective clothing
• Description of methods and materials used for containment (such as covering the drains and capping procedures)
• Description of methods and materials for clean-up (such as appropriate techniques for neutralization, decontamination, cleaning or vacuuming; appropriate techniques for avoiding production of gases/fumes by water or other diluent; use of suitable adsorbent materials; and equipment required for containment and clean-up)

An example of acceptable cross-referencing under item 6 would be including the statement "wear appropriate personal protective equipment, as indicated in Section 8". This would be acceptable because section 6 of the SDS provides the content of the information element "personal precautions, protective equipment and emergency procedures", as required by paragraph 6(a) of Schedule 1 of the HPR. The statement specifies that protective equipment is required and it clearly indicates where the additional information that outlines the protective equipment in detail can be found. This avoids having to repeat the information in both sections 6 and 8 of the SDS.

An example of unacceptable cross-referencing under item 6 would be including the statement "wear appropriate personal protective equipment". This would not be acceptable because the SDS does not indicate in which section of the SDS the user can locate the required protective equipment, particularly if needed in an emergency, nor does it provide information on the appropriate personal protective equipment.

Another example of unacceptable cross-referencing would be including the statement "see protective measures under sections 7 and 8". This would not be acceptable because, in this case, the cross-reference to sections 7 and 8 is included in place of providing, under section 6, the content of the required information element regarding protective measures.

Item 7 : Handling and storage: This section provides information on safe handling practices and conditions for safe storage of the hazardous product. Information must be provided in a manner that is consistent with the precautionary statements presented in Item 2 and must describe all storage and handling requirements relevant to the classification of the hazardous product. The required information consists of:

• Precautions for safe handling of the hazardous product, such as cautionary measures with regard to incompatible products, mixtures, materials and substances (PMMS), and precautions for minimizing the release of the hazardous product into the environment
• Description of the conditions for safe storage (for example, temperature, humidity, avoiding sunlight), including any incompatibilities
• Description of specific storage conditions (for example, appropriate ventilation, avoiding sources of ignition, including particular arrangements to avoid static build-up)

An example of acceptable cross-referencing under item 7 would be including the statement "store away from direct sunlight, food, drink and incompatible materials (see Section 10 for list of incompatible materials)". This would be acceptable because section 7 of the SDS provides the content of the information element "conditions for safe storage, including any incompatibilities", as required by paragraph 7(b) of Schedule 1 of the HPR. The statement informs users to store the product away from incompatible materials and it clearly indicates where the detailed list of incompatible materials can be found. This avoids having to repeat the information in both sections 7 and 10 of the SDS.

Another example of unacceptable cross-referencing under item 7 would be including the statement "see Section 10", to address the incompatibilities. This would not be acceptable because section 7 of the SDS does not provide the content of the required information element "conditions for safe storage, including any incompatibilities".

Item 8 : Exposure controls/personal protection: This section provides the occupational exposure limit values, biological limit values, information on engineering and/or administrative controls, and information on personal protective measures when using the hazardous product in order to minimize exposure. The required information consists of:

• Description of control parameters, including occupational exposure limit values or biological limit values and the source of those values
• Description of appropriate engineering controls (for example, use local or general exhaust ventilation, use only in an enclosed system or limit workers' exposure in exposure time, etc.)
• Description of personal protective measures to minimize exposure and prevent adverse effects from exposure, such as personal protective equipment to be worn by the worker (for example, lab coat, appropriate types of eye, face, skin or respiratory protection needed based on hazards and potential exposure, and type of glove material)

Item 9 : Physical and chemical properties: This section describes the physical and chemical properties associated with the hazardous product. The appropriate unit of measure must be provided for each property provided on the SDS where applicable. It is recommended to include the conditions (for example, temperature, pressure) under which the properties were measured, as applicable. The required information consists of:

• Physical state (solid, liquid, gas or mixture (include the states))
• Colour – in cases where the product has no colour, it can be described as "colourless"
  • It is not acceptable to provide a description of the colour as "clear", as this does not describe the colour of the product
  • However, "clear" may be used as an additional descriptor in conjunction with the colour, for example, "clear yellow"
• Odour – if there is a detectable odour, the SDS must include a description of the quality and the intensity of the odour
  • It is not acceptable to only describe the intensity, such as "mild" or "strong", without also providing a qualitative description of the odour (for example, the SDS could indicate "mild, alcohol-like" or "strong, acidic")
  • If there is no detectable odour, it can be described as "odourless" or "almost odourless"
• Melting point and freezing point
• Boiling point or initial boiling point and boiling range
• Flammability
• Lower and upper explosion limit or lower and upper flammability limit
• Flash point
• Auto-ignition temperature
• Decomposition temperature
• pH
• Kinematic viscosity
• Solubility
• Partition coefficient- n-octanol/water (logarithmic value)
• Vapour pressure
• Density and relative density
• Relative vapour density
• Particle characteristics – applicable to solids only
  • For example, indicate the particle size (median and range)
  • If available and appropriate, further properties may be indicated for example size distribution (range), shape and aspect ratio, and specific surface area

All information items must be addressed. If specific characteristics do not apply or are not available for the hazardous product, a statement that they do not apply (not applicable) or are not available must appear. Even if a physical or chemical property is listed in another section of the SDS (for example, flash point might also be listed in item 5), it must still be listed in item 9.

Suppliers may voluntarily add other physical or chemical parameters pertinent to the hazardous product, such as evaporation rate, oxidizing properties and molecular weight, to those listed above, as long as the information is not false or misleading (section 14.2 of the HPA prohibits information that is false, misleading or likely to create an erroneous impression with respect to the information that is required to be included in a label or SDS for a hazardous product).

In the case of a mixture, the information provided under this heading must be information that is available on the mixture as a whole. If information for the mixture as a whole is not available, then information that is available for the most relevant ingredient(s) in the mixture may be provided. In the latter case, the SDS should clearly indicate to which ingredient(s) the information applies.

Item 10 : Stability and reactivity: This section describes the possibility of hazardous reactions of the product under certain conditions and provides information on chemical stability.

The required information consists of:

• Description of the reactivity hazards
• Description of the chemical stability, including:
  • an indication of whether the hazardous product is stable or unstable under normal ambient and anticipated storage and handling conditions of temperature and pressure
• Description of any stabilizers that may be needed
• indication of any safety issues that may arise and which are associated with a change in physical appearance of the hazardous product
• Indication of the possibility of hazardous reactions, including:
  1. a statement of whether the hazardous product will react or polymerize, and could release excess pressure or heat, or create other hazardous conditions and
  2. a description of the conditions under which hazardous reactions may occur
• List of all conditions to avoid, including static discharge, shock or vibrations
  • Other examples of conditions to avoid may include contact with moisture or air, temperature, pressure or exposure to sunlight
• List of all classes of incompatible materials
  • For example, materials with which the hazardous product could react resulting in a hazardous situation
• List of any known or anticipated hazardous decomposition products
  • For example, products that could be produced as a result of use, storage or heating of the hazardous product

Item 11 : Toxicological information: This section provides a concise but complete description of the various toxic health effects and the data used to identify those effects. The required information includes:

• Information on likely routes of exposure (inhalation, ingestion, skin and eye contact)
• Description of the symptoms related to the physical, chemical and toxicological characteristics, including a description of first symptoms at the lowest exposures through to the consequences of severe exposure to the hazardous product
  • For example, "Headaches and dizziness may occur, before/leading to fainting or unconsciousness: large doses may result in coma and death"
• Description of the delayed and immediate effects
• Description of chronic effects from both short-term and long-term exposure
• The numerical measures of toxicity, including acute toxicity estimates such as the LD₅₀
  • Further guidance is provided in the discussion of the definition of Acute Toxicity Estimate ("ATE") in both Part 1 and Part 8 (discussion of section 8.1 of the HPR) of this guidance

In the case of a mixture, the information provided under this heading must be the information that is available on the mixture as a whole, and if information is not available on the mixture as a whole, then it must be information that is available on the hazardous ingredients in the mixture. In the latter case, the chemical name of the hazardous ingredient to which the information applies must be clearly indicated.

Item 12 : Ecological information (header required; content optional): As per subsection 4(2) of the HPR, the content of the specific information elements may be omitted as long as the item number and heading appear on the SDS. Environmental hazards are outside the scope of the HPR. If provided, this section offers information to evaluate the environmental impact of the product if it were released to the environment. The information may include:

• Data from toxicity tests performed on aquatic and/or terrestrial organisms, where available (for example, acute or chronic aquatic toxicity data for fish, algae, crustaceans, and other plants; toxicity data on birds, bees, plants)
• Whether there is a potential for the product to persist and degrade in the environment either through biodegradation or other processes, such as oxidation or hydrolysis
• Results of tests of bioaccumulation potential, making reference to the n-octanol-water partition coefficient (K_ow) and the bioconcentration factor, where available
• The potential for the product to move from the soil to the groundwater (indicate results from adsorption studies or leaching studies) or to a distance from the site of release
• Other adverse effects (for example, environmental fate (exposure), ozone layer depletion potential, photochemical ozone creation potential, endocrine disrupting potential, and/or global warming potential)

Item 13 :Disposal considerations (header required; content optional): As per subsection 4(2) of the HPR, the content of the specific information elements may be omitted as long as the item number and heading appear on the SDS. If provided, this section offers information on proper disposal practices, recycling or reclamation of the product and/or its container, and safe handling practices. The information may include:

• Description of appropriate disposal containers to use
• Recommendations on appropriate disposal methods to employ
• Description of the physical and chemical properties that may affect disposal activities
• Any special precautions for landfills or incineration activities

Item 14 : Transport information (header required; content optional): As per subsection 4(2) of the HPR, the content of the specific information elements may be omitted as long as the item number and heading appear on the SDS. The transport of dangerous goods is outside the scope of the HPR as this is regulated by Transport Canada.

If provided, this section offers the following transport information, including classification information for shipping and transporting of hazardous products by road, air, rail, or sea:

• United Nations (UN) number (4-digit identification number of the substance, mixture or group of chemical products)
• UN proper shipping name as provided for in the United Nations Model Regulations (UNMR)
• Transport hazard class(es) as provided for in the UNMR
• Packing group number as provided for in the UNMR
• Environmental hazards (for example, identify if it is a marine pollutant) according to the International Maritime Dangerous Goods Code (IMDG Code) and the UNMR
• Any special precautions which an employee should be aware of, or needs to comply with, in connection with transport or conveyance either within or outside their premises

Note: Item 14(f) [Information on transport in bulk (according to Annex II of the International Convention for the Prevention of Pollution From Ships, 1973, as modified by the Protocol of 1978 (MARPOL 73/78) and the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code)] was repealed from the HPR. However, it is strongly recommended that information pertaining to transport in bulk according to International Maritime Organization instruments continue to be provided under item 14 of the SDS, if that information is relevant to the hazardous product, for example, for products that are intended to be transported as bulk cargoes.

Item 15 : Regulatory information (header required; content optional): As per subsection 4(2) of the HPR, the content of the specific information elements may be omitted as long as the item number and heading appear on the SDS. If provided, this section offers information on the safety, health and environmental regulations, made within or outside Canada, specific to the product in question.

Item 16 : Other information: This section provides the date of the latest revision of the SDS. This section indicates the date of preparation if the SDS has not been revised or the date of the latest revision of the SDS in all other cases. This section may also state where the changes have been made to the previous version. Other information also may be included here (for example, abbreviations and acronyms used in the SDS).

Annex 2 – Information elements on safety data sheet – Biohazardous infectious materials, Schedule 2 of the HPR

Further guidance on the biohazardous infectious materials (BIM) safety data sheet (SDS) appendix is provided in the discussion of subsections 4(3) and 4(4) of the Hazardous Products Regulations (HPR).

Section I - Infectious agent: This section consists of the name, synonym or cross-reference, and characteristics of the BIM.

Section II - Hazard identification: This section identifies the pathogenicity/toxicity, epidemiology, host range, infectious dose, mode of transmission, incubation period and communicability (whether capable of transmission from person-to-person) of the BIM.

Section III - Dissemination: This section provides information on the reservoir (whether humans or animals), zoonosis (whether disease can be transmitted to humans from animals) and vectors of the BIM.

Section IV - Stability and viability: This section indicates the drug susceptibility/resistance (to which drugs is the BIM susceptible and resistant), susceptibility to disinfectants, physical inactivation (temperature, pressure and time after which the species can be inactivated) and survival of the BIM outside the host.

Section V - First aid/medical: This section provides information on the diagnostic methods that can be used to monitor the symptoms of infection, recommendations on the first aid and/or medical treatment, immunization and prophylaxis (preventive treatment or measures taken to prevent the disease).

Section VI - Laboratory hazard: This section provides information on the laboratory acquired infections, sources and specimens of the BIM, primary hazards and any other special hazards posed by the BIM.

Section VII - Exposure controls/personal protection: This section provides information on the risk group classification of the species (in accordance with the Human Pathogens and Toxins Act; further guidance is provided in the discussion of the definition of risk group classification in Part 1 of the HPR), the containment requirements for working with the BIM, protective clothing (such as lab coat, gloves, eye protection to avoid potential risks of exposure to splashes) and other precautions (such as use of biological safety cabinet, needles, syringes and other sharp objects) to be taken while working or handling the BIM.

Section VIII - Handling and storage: This section provides information on proper handling practices in case of spills, recommendations on appropriate disposal methods to employ, and information on proper storage conditions.

Section IX - Regulatory and other information: This section provides information on all the regulations with which the supplier or importer must comply for the import, use and transport of the BIM in Canada. This section also provides information on the date of the preparation of the SDS or, if applicable, the date of the last updated version of the SDS, and the name of the author who prepared or updated the SDS.

Annex 3 – Comparison of ingredient concentration disclosure and confidential business information protection requirements under the HPR, HMIRA, and the United States Hazard Communication Standard

This information will be included in the next update of this guidance.

Part 5 Exceptions

Part 5 "Exceptions" identifies exemptions from certain requirements of the Hazardous Products Act (HPA) and the Hazardous Products Regulations (HPR).

Sections 13 and 14 of the HPA outline the SDS and labelling requirements that a supplier must meet in order to sell and/or import a hazardous product intended for use, handling or storage in a Canadian workplace. The sale or importation of a hazardous product intended for use, handling, or storage in a Canadian workplace may be either partly or entirely exempted from the requirements of sections 13 and 14 of the HPA through the provisions of Part 5 of the HPR.

The exemptions from some requirements of the HPA and the HPR that are detailed in Part 5 are always optional; a supplier may choose not to use these exemptions.

The following definitions from the HPA apply in this Part.

The term "bailment" referred to in this guidance means the transfer of possession without the transfer of ownership. Please note that in civil law, which is a legal system in Canada that prevails only in the province of Quebec, the term "bailment" is not used, but an equivalent concept exists in that province. Therefore, as part of the definition of "sell", it was necessary to describe the equivalent of "bailment" under civil law, i.e., "in Quebec, make a Transfer of possession of a movable, for a specific purpose, without transferring ownership, and with the obligation to deliver the movable to a specified person or to return it, such as a transfer by means of a deposit, a lease, a pledge, a loan for use or a contract of carriage;".

Discussion of subsection 5(1) of the Hazardous Products Regulations

A laboratory sample is, by definition, a sample of a hazardous product (that is, it must meet the criteria to be classified in at least 1 of the hazard classes of these regulations) that is intended solely to be tested in a laboratory. Subject to the exemptions in Part 5, in the event that the laboratory sample meets the classification criteria of at least 1 hazard class, the HPA requirements to provide a label and SDS must be respected upon sale or import. It must be remembered that sale includes the provision of the sample for free and bailment of the sample.

Examples of laboratory samples include:

• diagnostic specimens (infectious blood, mucosa or tissue samples)
• soil or water samples contaminated with hazardous substances or mixtures
• chemical mixtures of hazardous products that are in the process of being developed
• quality control samples of hazardous products (developed products being tested for quality)

If the sample is not a hazardous product (that is, it does not meet the classification criteria for any hazard class), then it is not subject to the requirements of the HPA and HPR.

In addition to being a hazardous product, a laboratory sample in the context of the HPR

• does not include a sample that is to be used by the laboratory for
  • testing other product, material, mixture or substance (PMMS) (for example, titrants, HPLC (high pressure liquid chromatography) solvents, GC (gas chromatography) carrier gas, etc.); or
  • educational or demonstration purposes; and
• must individually weigh less than 10 kg

It is important to note that a sample of a hazardous product that is provided by a supplier to a customer, for the purpose of trying out the hazardous product (trial sample), does not meet the definition of a "laboratory sample". The laboratory sample exemptions set out in subsections 5(2) to (6) of the HPR do not apply in this situation. This hazardous product trial sample is subject to the full labelling and SDS requirements of the HPR, unless another exemption applies (such as subsection 5.4(1) for small containers of a capacity of 100 ml or less). The provision of such a free trial sample to a customer falls under the HPA definition of "sell" (section 2 of the HPA), since the definition includes "distribute — whether for consideration or not — to one or more recipients …".

It must be noted that under the HCS there is no SDS or labelling exemption for laboratory samples.

Discussion of subsection 5(2) of the Hazardous Products Regulations

This provision exempts laboratory samples of hazardous products that are classified only in the Biohazardous Infectious Materials (BIM) hazard class (Subpart 11 of Part 8 of the HPR) from the SDS requirements of the HPA, whether the sample is sold or imported, that is, the supplier need not have an SDS in their possession, provide or cause to be provided, obtain or prepare an SDS for such a laboratory sample. Furthermore, as discussed under subsection 5(5) of the HPR, such a sample is also exempted from full label requirements provided that reduced label requirements are met.

Note that, because it is subject to subsection 5(3), subsection 5(2) applies only to a sale with transfer of ownership (that is, paragraph (a) of the HPA definition of "sell") or an importation of laboratory samples classified only in the BIM hazard class.

It must be noted that these BIM laboratory samples are not to be used for the testing of other products, mixtures, materials or substances (paragraph 5(1)(a) of the HPR).

Discussion of subsection 5(3) of the Hazardous Products Regulations

The transfer of possession of a laboratory sample that is classified only in the BIM hazard class (Subpart 11 of Part 8 of the HPR) for a specific purpose, without transferring ownership, is exempt from the labelling and SDS requirements of section 13 of the HPA (that is, such a laboratory sample does not require any label or SDS).

In many cases, when a laboratory sample is sent by a supplier to a laboratory for testing, the ownership of the sample remains with the supplier. Once the test has been completed, what is left of the sample, if anything, may either be disposed of or returned, as instructed by the supplier. In order for this exemption to apply, the ownership of the sample must always remain with the supplier. In other words, the laboratory may have possession of the laboratory sample but not the ownership; this is what is meant by transfer of possession without transfer of ownership. It is important to note that this exemption does not apply to the importation of laboratory samples (that is, cross-border shipment does not qualify for this exemption).

As an example, this exemption allows health care workers to avoid having to produce an SDS or label for a diagnostic specimen that is known to be contaminated with a BIM.

Discussion of subsection 5(4) of the Hazardous Products Regulations

Laboratory samples that meet the description of either paragraph 5(4)(a) or (b) and whose possession is transferred for a specific purpose without transferring ownership are exempted from the SDS requirements of section 13 of the HPA, that is, the supplier does not need to have in their possession or provide or cause to be provided an SDS for these laboratory samples. These laboratory samples are either samples for which the chemical name or concentration of the hazardous product or its ingredients are unknown, or samples of hazardous products that are not yet available on the market.

Paragraph (a) of this exemption is meant to address samples of hazardous products sent to a laboratory for analysis to determine information necessary to the preparation of an SDS, while paragraph (b) is meant to address laboratory samples of hazardous products that have not yet been marketed (these samples may be part of a research and development program).

In many cases, when a laboratory sample is sent by a supplier to a laboratory for testing, the ownership of the sample remains with the supplier. Once the test has been completed, what is left of the sample, if anything, may either be disposed of or returned, as instructed by the supplier. In order for this exemption to apply, the ownership of the sample must always remain with the supplier. In other words, the laboratory may have possession of the laboratory sample but not the ownership; this is what is meant by "transfer of possession without transfer of ownership". It is important to note that this exemption does not apply to the importation of laboratory samples (that is, cross-border shipment does not qualify for this exemption).

This provision creates an exemption for the situation in which a supplier is required to disclose information on a laboratory sample when the supplier is sending the sample for the purpose of obtaining the very information that they are required to disclose, for example, the chemical name or concentration of the hazardous product or its ingredients.

Furthermore, as discussed under subsection 5(6) of the HPR, such a sample is also exempted from full label requirements provided that reduced label requirements are met.

Discussion of subsection 5(5) of the Hazardous Products Regulations

Laboratory samples that are classified only in the BIM hazard class (Subpart 11 of Part 8 of the HPR) are exempted, upon sale or importation, from the requirement to have on their labels the applicable pictogram, signal word, hazard statement and precautionary statement if reduced labelling requirements are met instead (that is, the label provides the chemical name or generic chemical name of the BIM if known by the supplier, the required bilingual statement and an emergency telephone number to obtain information that must be provided on the SDS). Requirements relating to information elements such as the product identifier (paragraph 3(1)(a) of the HPR) and the initial supplier identifier (paragraph 3(1)(b) of the HPR) are not exempted; these information elements must still be provided on the label.

Note that because it is subject to subsection 5(3), subsection 5(5) does not apply to transfers of possession of a laboratory sample for a specific purpose without transferring ownership. See discussion of subsection 5(3) above.

Since subsection 5(5) of the HPR deals with laboratory samples that are classified only in the BIM hazard class, the requirement to provide the "chemical name or generic chemical name" on the label must be met by providing the name of the infectious material, that is, the scientific name of the infectious microorganism, nucleic acid or protein, or a generic chemical name if the exact identity of the microorganism, nucleic acid or protein is unknown. The generic chemical name may be used for laboratory samples exempted under subsection 5(5) of the HPR without filing a claim for CBI under the Hazardous Materials Information Review Act (HMIRA). For more information regarding CBI, see the discussions of subsections 5.7(1) to (11) and Appendix A. The terms "generic chemical name"and "commonly known generic name"must not be confused. The commonly known generic name refers to a synonym (for example, turpentine) of a chemical name, whereas the generic chemical name (for example, primary alcohol), within the context of subsection 5(5) of the HPR, may be used when the exact chemical identity is not known. For more information about generic chemical names please refer to Appendix B.

According to subsection 5(2) of the HPR, such samples are also exempted from the SDS requirements of the HPA; that is, the supplier need not have in their possession, provide or cause to be provided, obtain or prepare an SDS for such a laboratory sample.

Discussion of subsection 5(6) of the Hazardous Products Regulations

Laboratory samples that meet the description of either paragraph 5(6)(a) or (b) and whose possession is transferred for a specific purpose without a transfer of ownership are exempted from the requirement to have on their labels the applicable pictogram(s), signal word, hazard statement and precautionary statement if reduced labelling requirements are met instead (that is, the label provides the chemical name or generic chemical name of the hazardous product or its ingredients if known by the supplier, the required bilingual statement and an emergency telephone number to obtain information that must be provided on the SDS).

These are either samples for which the chemical name or concentration of the hazardous product or its ingredients are unknown, or samples of hazardous products that are not yet available on the market. Requirements relating to information elements such as the product identifier (paragraph 3(1)(a) of the HPR) and the initial supplier identifier (paragraph 3(1)(b) of the HPR) are not exempted; these information elements must still be provided on the label.

Subparagraphes (a)(i) and a(ii) of this label exemption are meant to address samples of hazardous products sent to a laboratory for analysis to determine information necessary to the preparation of the label, while subparagraph (a)(iii) is meant to address laboratory samples of hazardous products that have not yet been marketed (these samples may be part of a research and development program).

Example of a laboratory sample label according to subsection 5(6) is provided below:

It is important to note that a laboratory sample can be subject to both subsection 5(4) (SDS exemption) and subsection 5(6) (partial label exemption).

In many cases, when a laboratory sample is sent by a supplier to a laboratory for testing, the ownership of the sample remains with the supplier. Once the test has been completed, what is left of the sample, if anything, may either be disposed of or returned, as instructed by the supplier. In order for this exemption to apply, the ownership of the sample must always remain with the supplier. In other words, the laboratory may have possession of the laboratory sample but not the ownership; this is what is meant by "transfer of possession without transfer of ownership". It is important to note that this exemption does not apply to the importation of laboratory samples (that is, cross-border shipment does not qualify for this exemption).

This exemption is similar to the one set out in subsection 5(5) which is for laboratory samples that are only classified in the BIM hazard class.

The generic chemical name may be used for laboratory samples exempted under subsection 5(6) of the HPR without filing a claim for CBI under the HMIRA. For more information regarding CBI, see the discussions of subsections 5.7(1) to (11) and Appendix A. The terms "generic chemical name" and "commonly known generic name" must not be confused. The commonly known generic chemical name refers to a synonym (for example, turpentine) of a chemical name whereas the generic chemical name (for example, primary alcohol), within the context of subsection 5(6) of the HPR, may be used when the exact chemical identity is not known or to provide information about the chemical without revealing its exact identity. For more information about generic chemical names please refer to Appendix B of this guidance.

Discussion of subsection 5.1(1) of the Hazardous Products Regulations

The Nuclear Safety and Control Act defines "nuclear substance" (formally defined as "prescribed substance") to include only the radioactive components of radioactive nuclide mixtures. As a result, non-radioactive carriers which are hazardous products in radioactive nuclide mixtures are subject to the HPR requirements under the HPA even though the non-application for nuclear substances within the meaning of the Nuclear Safety and Control Act pursuant to paragraph 12(d) of the HPA remains.

This provision provides an exemption from the label and SDS requirements upon the sale or importation of mixtures containing radioactive nuclides and small quantities of solid (≤ 1 g), liquid or gaseous (≤ 1 ml) non-radioactive carriers which are hazardous products, except where the carrier is classified in 1 or more of the following hazard classes:

• Carcinogenicity;
• Germ Cell Mutagenicity;
• Reproductive Toxicity;
• Acute Toxicity (Oral or Dermal) — Category 1 or Acute Toxicity (Inhalation) — Category 1 or 2; or
• Biohazardous Infectious Materials.

This exemption takes into account that in chemical and clinical laboratory environments:

• radioactive mixtures usually involve very minimal quantities of carrier materials; and
• laboratory workers who handle radioactive nuclides receive specific training to avoid any exposure.

For example, consider a radioactive nuclide mixture with a non-radioactive carrier that is liquid, present at 2 ml, and is classified in Carcinogenicity — Category 2. If this hazardous product is sold or imported, a label and SDS that are compliant with the HPR are required because the amount of the non-radioactive carrier liquid exceeds 1.0 ml and the carrier is classified in 1 or more of the hazard classes and categories listed in paragraph 5.1(1)(b). However, as another example, consider a radioactive nuclide mixture with a non-radioactive carrier that is a solid present at 0.5 g, and classified only in Skin Corrosion — Category 1. If this mixture is imported or sold, it is exempt from the labelling and SDS requirements of the HPA because the amount of non-radioactive carrier solid is below 1.0 g and the carrier is not classified in any of the hazard classes listed in paragraph 5.1(1)(b).

Discussion of subsection 5.1(2) of the Hazardous Products Regulations

Under the HPR, a hazardous product or its container must have a label that complies with the regulations. This requirement means that, every subsequent container in which the hazardous product is packaged must provide the same label information elements as the innermost container or the hazardous product. However, section 5.2 of the HPR exempts, under specified conditions, the outer container of a hazardous product from the requirement to have an HPR-compliant label (see discussion of section 5.2 for more information).

Subsection 5.1(2) of the HPR exempts mixtures containing radioactive nuclides and 1 or more non-radioactive hazardous product carriers (which are not already exempted by subsection 5.1(1)) from the label requirements of the HPA with respect to the inner container label, as long as there is an outer label with the required information elements. For example, if such a mixture is packaged in a bottle which is in a red container which, in turn, is in a blue container, through this provision, the label may appear only on the outer blue container. The bottle and the red container are not required to have an HPR label.

This provision is precautionary in nature. Since the outer label has the required information, it would not be necessary to increase the risk of exposure by getting close to the radioactive material in order to read the label on an inner container. As these hazardous products containing radioactive nuclides with 1 or more non-radioactive hazardous product carriers are handled in entirely closed and shielded "hot cells" or by remote control, every effort is made to avoid personal contact. Only the outer container (as defined in subsection 1(1)) requires labelling according to the HPR since workers will normally handle only that outer container directly. It is important to note that radioactive nuclides are regulated under the Nuclear Safety and Control Act and its regulations.

Discussion of subsection 5.1(3) of the Hazardous Products Regulations

This provision exempts mixtures containing radioactive nuclides and 1 or more non-radioactive hazardous product carriers (which are not already exempted by subsection 5.1(1) of the HPR) from specific label element requirements, namely, the initial supplier identifier and the precautionary statements. The pictogram(s), signal word and hazard statements must be provided on the label as this exemption only allows the omission of the initial supplier identifier and precautionary statements.

It should be understood that the exemptions in subsections 5.1(2) and (3) can apply at the same time, such that the reduced label information elements would only appear on the outermost container of the radioactive nuclide hazardous product.

Discussion of section 5.2 of the Hazardous Products Regulations

Under the HPR, a hazardous product or its container must have a label that complies with the regulations.

Paragraph 5.2(a) provides an exemption to this requirement whereby an outer container in which a hazardous product is packaged is not required to have an HPR-compliant label if the label on the inner container (or on the hazardous product itself) is visible and legible through the outer container during normal conditions of storage and handling. This applies, for example, in situations where the outer container is either entirely transparent (see Figure 9 below) or it has a transparent window (see Figure 10 below) that allows the user to see the label on the inner container that is packaged inside the outer container.

Paragraph 5.2(b) provides another exemption whereby the outer container in which a hazardous product is packaged is not required to have an HPR-compliant label if the outer container meets the labelling requirements set out in the Transportation of Dangerous Goods Regulations (TDGR)for this hazardous product. See Figure 11 for an example of an outer container with TDGR labelling.

It is important to note that if a hazardous product is packaged in only 1 container, this exemption does not apply. This is because the definition of "outer container" (in subsection 1(1) of the HPR) excludes an outward container if that is the only container of a hazardous product. For example, a pail or drum (of less than 450 liters, that is, not a bulk shipment as per subsection 5.5(1)) of a hazardous product that has TDGR labelling would also require an HPR compliant label. However, for such a label, the exemption in section 5.10 of these regulations (relating to the repetition of symbols on the label) may apply, as may other applicable exemptions.

Note that, under the HCS, the label is required to be on the immediate container of a hazardous product, but need not appear on the outside packaging.

Figure 9 - Text description

Three transparent containers

Figure 10 - Text description

A container with a window

Figure 11 - Text description

An outer container with TDGR labelling

Discussion of section 5.3 of the Hazardous Products Regulations

Label — outer container — at least two hazardous products

5.3 In the case of an outer container in which at least two different hazardous products are packaged, subsection 3(1) does not apply if the label provides the following information elements:

1. (a) the product identifier for each hazardous product contained in the outer container;
2. (b) the initial supplier identifier;
3. (c) subject to subsection 3.6(3), the pictogram set out in column 3 of Schedule 3 designated for each category or subcategory in which each hazardous product contained in the outer container is classified;
4. (d) the precautionary statement applicable to the storage of each of the hazardous products contained in the outer container; and
5. (e) the statement "See individual product labels for signal words, hazard statements and precautionary statements/Voir les étiquettes sur chacun des produits pour les mentions d'avertissement, les mentions de danger et les conseils de prudence".

Under the HPR, a hazardous product or its container(s) must have a label that complies with the regulations. This requirement means that, unless an exemption applies, every subsequent container in which the hazardous product is packaged must also provide the same label information elements as the innermost container or the hazardous product.

Section 5.3 provides an exemption for different hazardous products with HPR-compliant labels that share the same outer container. This provision applies to situations such as a "kit" (see the image below for an example of a kit), where 2 or more different hazardous products are packaged in the same outer container, usually for a common purpose. However, this exemption is not limited to kits; any outer container in which at least 2 different hazardous products are packaged could benefit from this exemption. It is important to note that outer containers used to transport hazardous products do not require an HPR label if they are labelled in accordance with the TDGR (paragraph 5.2(b) of the HPR).

An outer container containing 2 or more different hazardous products is exempt from the requirement to provide all the label information elements if the label of the outer container provides the following:

• the product identifiers,
• initial supplier identifier(s)
• pictogram(s)
• storage precautionary statements, and
• the statement "See individual product labels for signal words, hazard statements and precautionary statements/Voir les étiquettes sur chacun des produits pour les mentions d'avertissement, les mentions de danger et les conseils de prudence"

Therefore, on the outer container, the following label information elements may be omitted:

• signal word
• hazard statement(s)
• response, prevention and disposal precautionary statements
• supplemental information (where applicable)

As required by the HPR, each individual hazardous product packaged in the shared outer container must meet the full labelling requirements of the HPR, subject to any other applicable exemptions such as subsections 5.4(1) and (2).

This exemption applies only if there is more than 1 hazardous product in the outer container; if there is only 1 hazardous product, then all label information elements of this hazardous product must also be provided on the outer container unless 1 of the exemptions in section 5.2 applies. Where several containers of the same hazardous product are packaged together in 1 outer container, this exemption does not apply. In this situation, all label information elements of the hazardous product must also be provided on the outer container unless 1 of the exemptions in section 5.2 applies.

Note that, under the HCS, only the immediate container of the hazardous product inside the outer container is required to be labelled in accordance with the HCS; however, the label may also appear on the outside packaging.

Figure 12 - Text description

A box with 16 containers in front of the box shows an example of a kit

Discussion of subsection 5.4(1) of the Hazardous Products Regulations

This is an exemption for hazardous products packaged in small capacity containers (less than or equal to 100 ml) from the requirements to have precautionary statements and hazard statements on the labels. This exemption is solely limited to labels. A full SDS is still required. Where the container of a capacity of 100 ml or less is packaged in another container that also has a capacity of 100 ml or less, this exemption would also apply to the second container.

Note that, under the HCS, there are no small container exemptions. However, OSHA permits practical accommodations where a manufacturer can show that it is infeasible to include all of the label information directly on the small container. In such cases, at a minimum, the immediate container must bear the product identifier, pictograms, signal word, and the manufacturer's name and telephone number. In addition, the outer package must have the full label information (and the inner label must also note that the outer package has the full label information).

Discussion of subsection 5.4(2) of the Hazardous Products Regulations

This exemption applies to hazardous products packaged in extremely small capacity containers (3 ml or less) where the label must be removed in order to allow the product to be used in the intended manner. This exemption is solely limited to labels; the omitted precautionary statements and hazard statements are required to be provided in section 2 of the SDS. In addition to being allowed to use the exemption under subsection 5.4(1) of the HPR, these labels are not required to remain attached to the hazardous product during normal conditions of use, despite the requirement specified in section 3.5 of the HPR. This exemption is intended to accommodate situations where the label may interfere with the normal use of the product. The label could be made removable to enable product use.

An example of a product for which this exemption would be applied would be a 2 ml HPLC vial containing a hazardous product. The label on this product could be anticipated to be required to be removed, and therefore, at least partially destroyed during the normal use of the product.

On the other hand, a 2 ml vial containing a hazardous product, where the product is only intended to be decanted from the vial, would not qualify for this extremely small capacity container exemption. The extremely small capacity container exemption only applies when the label interferes with the normal use of the hazardous product. In this example, the label does not interfere with the normal use of the hazardous product as the hazardous product is only intended to be decanted from the small container.

Contrary to the exemption in subsection 5.4(1) of the HPR, this exemption applies only to the immediate container in which the hazardous product is packaged. If the hazardous product container is packaged in a subsequent container, the exemption does not apply to this subsequent container even if the latter container is also of a capacity of 3 ml or less. This is because the label on this subsequent container cannot possibly interfere with the normal use of the hazardous product, as the immediate container would be removed from the subsequent container prior to use.

Note that, under the HCS, there are no small container exemptions. However, OSHA permits practical accommodations where a manufacturer can show that it is infeasible to include all of the label information directly on the small container. In such cases, at a minimum, the immediate container must bear the product identifier, pictograms, signal word, and the manufacturer's name and telephone number. In addition, the outer package must have the full label information (and the inner label must also note that the outer package has the full label information).

Discussion of subsections 5.5(1) and (2) of the Hazardous Products Regulations

Definition of "bulk shipment"

5.5(1) In this section, "bulk shipment" means a shipment of a hazardous product that is contained in any of the following, without intermediate containment or intermediate packaging:

1. (a) a vessel that has a water capacity equal to or greater than 450 l;
2. (b) a freight container, road vehicle, railway vehicle or portable tank;
3. (c) the hold of a ship; or
4. (d) a pipeline.

Bulk shipments and unpackaged hazardous products

(2) The sale or importation of a bulk shipment or a hazardous product without packaging of any sort is exempt from the application of paragraph 13(1)(b) or 14(b) of the Act.

This provision exempts the sale and import of unpackaged hazardous products and hazardous products that meet the definition of bulk shipment from the labelling requirements of the HPR. For example, oil in a tanker, polymer pellets for extrusion in a freight container, metal ingots, small (for example, grain or granule sized solids) and large (for example, metal beams) unpackaged products would be exempted from the labelling requirements of the HPR. However, if any type of intermediate containment or packaging is used, this exemption would not apply. For example, a pallet of unpackaged hazardous products that is shrink-wrapped is not exempt from the labelling requirements since the shrink-wrap is a packaging to which a label may be applied.

This labelling exemption applies to situations where the hazardous product is shipped to the customer, as well as situations where the hazardous product is picked up by the customer at the supplier's location.

Discussion of subsections 5.6(1) and (2) of the Hazardous Products Regulations

Definition of "complex mixture"

5.6(1) In this section, "complex mixture" means a mixture that has a commonly known generic name and that is

1. (a) naturally occurring;
2. (b) a fraction of a naturally occurring mixture that results from a separation process; or
3. (c) a modification of a naturally occurring mixture or a modification of a fraction of a naturally occurring mixture that results from a chemical modification process.

Complex mixture

(2) The sale or importation of a hazardous product that is a complex mixture is exempt from the application of paragraph 4(1)(b) in respect of the requirements set out in paragraphs 3(2)(a) and (d) of Schedule 1, and in paragraphs 3(2)(b) and (c) of that Schedule, if that information is available and applicable, in relation to the ingredients of the complex mixture, if the commonly known generic name of the complex mixture is provided for item 3 of the safety data sheet.

Under the HPR, the ingredient(s) that trigger the classification of a mixture in a health hazard class are required to be disclosed in item 3 of the SDS. In the case of a hazardous product that is a complex mixture, the components of the mixture may be unknown or exceptionally numerous and their concentrations may vary widely. Furthermore, in a significant number of cases, toxicological studies as well as physical tests may have been conducted on the complex mixture. In some cases, results may be available only for the complex mixture, not its individual ingredients. Examples of complex mixtures include: turpentine, petroleum distillates and crude oil. However, a synthetic mixture of gases which has approximately the same composition as atmospheric air does not meet the definition of a complex mixture because it is not naturally occurring.

For any ingredient in a complex mixture that is required to be disclosed on the SDS, subsection 5.6(2) provides an exemption whereby the following information elements for the ingredient may be omitted:

• chemical name
• common name and synonyms (if that information is available and applicable)
• CAS registry number and any unique identifiers (if that information is available and applicable) and
• concentration

This exemption applies only if the commonly known generic name of the complex mixture is provided in item 3 of the SDS. Therefore, for such a hazardous product, the SDS may simply disclose, for example, "Turpentine", under item 3 of the SDS, instead of the information elements specified in paragraphs 3(2)(a) through (d) of Schedule 1 of the HPR. There is no requirement to list all known ingredients in turpentine that meet the criteria for disclosure.

If a hazardous product is comprised solely of a complex mixture that is only classified in 1 or more physical hazard class(es), this exemption, including its requirement to disclose the commonly known generic name of the complex mixture, does not apply. This is because only ingredients that present health hazards are required to be disclosed under item 3(2) of Schedule 1 of the HPR, and in this case, there would be no such ingredients. It is important to note that the requirements with respect to disclosure of the classification or, in the case of physical and health hazards not otherwise classified, a description of the hazards of the complex mixture under item 2 of the SDS must still be met.

The terms "commonly known generic name" and "generic chemical name"must not be confused. The commonly known generic name refers to a synonym (for example, turpentine) of a chemical name whereas the generic chemical name (for example, primary alcohol) may be used when the exact chemical identity is not known or to provide information about the chemical without revealing its exact identity. A generic chemical name must be used only when a claim for CBI was granted under the HMIRA or the hazardous product is a laboratory sample exempted under subsections 5(5) or 5(6) of the HPR. For more information regarding CBI exemptions, see the discussion of subsections 5.7(1) to (11) and Appendix A. For more information about generic chemical names, please refer to Appendix B.

It must be noted that there are no exemptions for complex mixtures under HCS.

Discussion of subsection 5.6(3) of the Hazardous Products Regulations

This provision is similar to subsection 5.6(2) except that, rather than addressing hazardous products that are entirely comprised of a complex mixture, it addresses hazardous products that contain a complex mixture along with other ingredients (for example, a mixture that contains 60% turpentine plus other ingredients).

This provision addresses any hazardous product that is a mixture which contains a complex mixture that is classified in a category or sub-category of a health hazard class and is present above the corresponding concentration limit. For any ingredient in the complex mixture that is required to be disclosed on the SDS, subsection 5.6(3) provides an exemption whereby the following information elements may be omitted:

• chemical name
• common name and synonyms (if that information is available and applicable)
• CAS registry number and any unique identifiers (if that information is available and applicable) and
• concentration

This exemption applies only if the commonly known generic name of the complex mixture and its concentration in the hazardous product are provided in item 3 of the SDS. Therefore, for such a hazardous product, the SDS may simply disclose, for example, "Turpentine – 60%", under item 3 of the SDS, instead of the information elements specified in paragraphs 3(2)(a) through (d) of Schedule 1 of the HPR. There is no requirement to list all known ingredients in turpentine.

Where a hazardous product that is a mixture contains a complex mixture that is only classified in one or more physical hazard class(es), there is no requirement to disclose the commonly known generic name of the complex mixture or its concentration. Item 3(2) of Schedule 1 of the HPR specifies that only ingredients that present health hazards are required to be disclosed.

Discussion of subsection 5.6(4) of the Hazardous Products Regulations

When a complex mixture is present as an ingredient in a mixture below the concentration limit that would trigger classification in a category or subcategory of a health hazard class, this ingredient (the complex mixture) is not required to be disclosed. However, when subsection 2.5(1) applies, subsection 5.6(4) specifies that the commonly known generic name and the concentration of the complex mixture must be disclosed under item 3 of the SDS. Subsection 2.5(1) addresses situations where available data demonstrate that an ingredient presents a hazard at the concentration at which it is present in the mixture, despite being present in the mixture at a lower concentration than the concentration limit for a particular category or subcategory of a health hazard class. In such situations, since the ingredient (complex mixture) triggers the classification of the mixture in a category or subcategory of the health hazard class, the ingredient (complex mixture) must be disclosed.

Note that "commonly known generic name" and "generic chemical name"must not be confused. The commonly known generic name refers to a synonym (for example, turpentine) of a chemical name whereas the generic chemical name (for example, primary alcohol) may be used when the exact chemical identity is not known or to provide information about the chemical without revealing its exact identity. A generic chemical name must be used only when a claim for CBI was granted under the HMIRA or the hazardous product is a laboratory sample exempted under subsections 5(5) or 5(6) of the HPR. For more information regarding CBI exemptions, see the Discussion of subsections 5.7(1) to (11) and Appendix A. For more information about generic chemical names please refer to Appendix B.

Discussion of subsections 5.7(1), (2) and (3) of the Hazardous Products Regulations

A supplier may file a claim for exemption from disclosing CBI with Health Canada under subsection 11(1) of the HMIRA to request an exemption from requirements under the HPA and HPR to disclose specific information which the supplier considers to be CBI (for example, chemical name, concentration or concentration range of a hazardous ingredient).

Subsections 5.7(2) and (3) of the HPR specify the information that must be disclosed on an SDS and to replace the information elements for which a claim for exemption is filed. The replacement information must consist of:

• a statement that a claim was filed
• the date that the claim was filed and
• the registry number assigned to the claim under the HMIRA

until the time period specified in HPR subsection 5.7(3)

The replacement information must appear in lieu of each information element for which a claim was filed; however, this could be accomplished by inserting an asterisk, footnote, or other symbol in lieu of the required information, which would refer to this replacement information located elsewhere on the SDS and if applicable, on the label. The replacement information must be presented in a manner that allows it to be easily related to the information for which a claim was filed.

In addition to this reference to the replacement information using, for example, an asterisk or footnote, the information elements on the SDS and if applicable, on the label for which a claim is filed may be accompanied by words such as "trade secret" or "proprietary".

It is important to note that if a claim was filed for any of the following information elements:

• chemical name
• common name and synonyms
• CAS registry number and any other unique identifier or
• chemical name of impurities, stabilizing solvents or stabilizing additives

then the generic chemical name (GCN) must also appear to replace any of those information elements, in accordance with subsection 5.7(5) of the HPR.

If a GCN is required, the claimant must propose a GCN upon filing a claim. This GCN will be reviewed as part of the claim for exemption process. The required GCN must appear on the SDS and on the label if applicable with the replacement information. This replacement information and the GCN indicate that a claim for exemption from the disclosure of CBI has been filed with Health Canada in accordance with the HMIRA.

The following is an example of what Section 3 of an SDS could look like to include a clear link to replacement information and a GCN:

Table 5.1 Example of a table in Section 3 of an SDS

Substance	CAS number	% (w/w)
Alcohol Table 5.1 Footnote *	Proprietary Table 5.1 Footnote *	Proprietary Table 5.1 Footnote *
Trichloroisocyanuric Acid	87-90–1	0.1%
* HMIRA RN:3333 - Filing Date January 1, 2021

In situations where a partially valid or invalid claim validity decision has been issued, Health Canada may issue an order under subsection 14(1) of the HMIRA requiring the claimant to comply, in the manner and time specified in the order, in relation to the invalid part of the claim. The order could require information that was found not to be CBI to be disclosed on the SDS or label that accompanies the claim for exemption, or it could require the removal of information, including the HMIRA registry number, from a SDS or label.

In situations where an SDS compliance decision has been issued, Health Canada may issue an order under subsection 18(1) of the HMIRA requiring the claimant to comply in the manner and within the time specified in the order, in relation to SDS or label non-compliances.

The replacement information specified in subsection 5.7(3) of the HPR must remain on the SDS and if applicable, on the label, up to, either:

1. (i) in the case that no order was issued, a maximum of 30 days after all judicial reviews and appeals of the claim validity decision are exhausted or
2. (ii) in the case that an order was issued, the end of the period that begins the day after the day on which all judicial reviews and appeals of the claim validity decision are exhausted and does not exceed the period specified in the order

Once this period of time is over, provided that any orders have been complied with, the replacement information in this provision must be changed to the replacement information indicated in subsection 5.7(4) of the HPR if the claim or a portion of the claim is determined to be valid. This replacement information must be used until the end of the exemption period, which is 3 years after the final disposition of the proceedings, as per subsection 19(2) of HMIRA.

Discussion of subsection 5.7(4) of the Hazardous Products Regulations

Information to be disclosed

5.7(4) A supplier who receives notice of a determination made under the Hazardous Materials Information Review Act that their claim or a portion of their claim for exemption from a requirement to disclose information in respect of a hazardous product on a safety data sheet or a label is valid must, during the period beginning no later than the end of the applicable period specified in subsection (3) and on compliance with any order issued under subsection 14(1) or 18(1) of the Hazardous Materials Information Review Act, if applicable, and ending on the last day of the exemption period, in respect of the sale or importation of the hazardous product, provide on the safety data sheet and, if applicable, on the label of the hazardous product or container in which the hazardous product is packaged the following information:

1. (a) a statement that an exemption has been granted;
2. (b) the date of the determination granting the exemption; and
3. (c) the registry number assigned to the claim under the Hazardous Materials Information Review Act.

Subsections 5.7(2) and (4) of the HPR specify that where a decision is made by Health Canada that a claim for exemption is valid, the replacement information in subsection 5.7(3) must be changed to the information specified in subsection 5.7(4). This requirement means that the statement that a CBI claim was filed must be changed to a statement that an exemption has been granted, and the date when the claim was filed must be changed to the date when the exemption was granted. The replacement information applies only for those information elements for which the CBI claim filed under the HMIRA was granted.

The replacement information specified in subsection 5.7(3) must remain on the SDS and if applicable, on the label, up to, either:

1. (i) in the case that no order was issued, a maximum of 30 days after either the end of the appeal period with no appeal being filed or, if an appeal is filed, until the final legal determination of the issue being appealed, or
2. (ii) in the case that no order was issued, a maximum of 30 days after the day on which all judicial reviews are exhausted
3. (iii) in the case that an order was issued, the end of the period that begins the day after the day on which all judicial reviews and appeals of the claim validity decision are exhausted and does not exceed the period specified in the order

Once this period of time is over, provided that any orders have been complied with, the replacement information in this provision must be changed to the replacement information indicated in subsection 5.7(4) of the HPR if the claim was granted. This replacement information must be used until the end of the exemption period, which is 3 years after the final disposition of the proceedings, as per subsection 19(2) of HMIRA. An applicable order has not been complied with, no further sale or import of the product can take place until compliance has been achieved.

Discussion of subsection 5.7(5) of the Hazardous Products Regulations

If the information being claimed for exemption from disclosure is the chemical name, common name, synonym, CAS registry number or any unique identifier of an ingredient, material or substance or the chemical name of an impurity or stabilizing solvent or stabilizing additive in the product required to be disclosed on the SDS, these means of identification must be replaced by a GCN of the ingredient, material or substance. For more information about the GCN please refer to Appendix B.

The GCN proposed by the claimant when the claim was filed must remain the same unless Health Canada requested changes. The GCN must appear on the SDS with the replacement information specified in subsection 5.7(3) or (4) (as applicable).

The "generic chemical name" and "commonly known generic name" must not be confused. The commonly known generic name refers to a synonym (for example, turpentine) of a chemical name whereas the GCN (for example, primary alcohol), within the context of section 5.7 of the HPR, is used to preserve a CBI. The GCN provides information about the chemical without revealing its exact identity.

Discussion of subsection 5.7(6) of the Hazardous Products Regulations

If the concentration or actual concentration range of an ingredient in a hazardous product that is a mixture is the subject of a claim for CBI exemption under the HMIRA, then it need not be disclosed on the SDS. Although subsection 5.7(2) of the HPR states that information element(s) that are the subject of a pending or granted claim for exemption must be changed to the replacement information pursuant to either subsection 5.7(3) or (4) of the HPR (as applicable), to avoid any confusion, subsection 5.7(6) of the HPR clearly states that if a CBI claim is filed for concentration then the concentration or actual concentration range need not be disclosed. However, suppliers are encouraged to disclose a replacement concentration range instead of the true concentration or true concentration range. See Part 4, Annex 1 and Annex 3 of this guidance for more information on disclosure requirements and CBI.

Discussion of subsection 5.7(7) of the Hazardous Products Regulations

This provision is an exemption for any subsequent supplier who wants to sell or import hazardous products for which a CBI claim was granted to a first supplier. This exemption provides the subsequent supplier an exemption from disclosure of the ingredient identity information in respect of which a CBI claim was granted to the first supplier under the HMIRA. It is important to note that replacement information must be provided in lieu of the withheld information elements for which a CBI claim was granted.

It is also important to note that the term "first supplier" must not be confused with "initial supplier identifier" as the term "first supplier" conveys a specific meaning with respect to this CBI provision.

"First supplier" means a supplier who is exempted from the requirement to disclose the information specified in subsection 11(1) of the HMIRA, by virtue of that Act.

"Initial supplier identifier" means the name, address and telephone number of

• the manufacturer or
• the importer of the hazardous product who operates in Canada

"Subsequent supplier" means a supplier who sells or imports a hazardous product that is the subject of an exemption granted to the first supplier from the requirement to disclose the information specified in subsection 11(1) of the HMIRA.

Importation

This exemption applies to the importation of a hazardous product by a Canadian importer (subsequent supplier) from a foreign (non-Canadian) supplier (first supplier) who was granted a CBI claim for exemption under the HMIRA. It must be noted that once the hazardous product is imported, if the importer wants to sell the same hazardous product (or a mixture containing this hazardous product) they may use the "sale" exemption explained below, since they remain a subsequent supplier at that point.

Sale

This exemption may be used by any subsequent supplier (including the importer mentioned above) who wants to sell in Canada the same hazardous product (or a mixture containing this hazardous product) for which a CBI claim under the HMIRA was granted to the "first supplier" (Canadian or foreign). It is important to note that any downstream supplier in the distribution chain who sells the same hazardous product (or a mixture containing this hazardous product) in Canada is also a subsequent supplier and, as such, may use this exemption.

Conditions

As explained above, subsection 5.7(7) of the HPR allows the subsequent supplier to withhold the same information elements from the SDS, and label if applicable, that were the subject of a valid claim for exemption by the first supplier. This subsection pertains specifically to CBI related to chemical identification information. In order to qualify for this exemption, these information elements must not be known to the subsequent supplier, or the subsequent supplier must have obtained the information in confidence and is obligated to maintain the confidentiality of the information. In the second situation, the subsequent supplier is obligated to maintain the confidentiality of the information elements. The subsequent supplier may sell the hazardous product as is or may sell a new mixture which contains the first supplier's hazardous product as an ingredient; in both situations subsection 5.7(7) of the HPR applies. It is important to note that the supplier is still responsible for ensuring that the product is accurately classified, even if the ingredients of the first supplier's product are not known to the subsequent supplier.

Where the subsequent supplier was granted their own claim for CBI exemption under the HMIRA, the requirements for replacement information depend on what information the subsequent supplier has claimed for exemption. In this case, discussion about the particular case with Health Canada is recommended.

Where the subsequent supplier was not granted a claim for CBI exemption under the HMIRA, the replacement information of the first supplier, namely,

• the first supplier's claim registry number
• the date when the first supplier's claim was granted
• a statement that a claim for exemption has been granted and
• the generic chemical name provided by the first supplier

must appear on the SDS provided by the subsequent supplier, along with the words "other supplier/autre fournisseur" in parentheses next to the first supplier's replacement information.

Discussion of subsection 5.7(8) of the Hazardous Products Regulations

Sale or importation — paragraph 3(2)(d) of Schedule 1

This provision is similar to subsection 5.7(7) of the HPR but relates solely to the concentration or actual concentration range of an ingredient in a hazardous product that is a mixture. Subsection 5.7(8) of the HPR is an exemption for any subsequent supplier who wants to sell or import hazardous products for which a CBI claim, for the concentration or actual concentration range of an ingredient, was granted to a first supplier. This exemption provides the subsequent suppliers an exemption from the disclosure of the concentration or actual concentration range information in respect of which a CBI claim was granted under the HMIRA. Replacement information must be provided in lieu of the withheld information element for which a CBI claim was granted.

It is important to note that the term "first supplier" must not be confused with "initial supplier identifier" as the term "first supplier" conveys a specific meaning with respect to this CBI provision. Refer to subsection 5.7(7) for more information.

Importation

This exemption applies to the importation of a hazardous product by a Canadian importer (subsequent supplier) from a foreign (non-Canadian) supplier (first supplier) who was granted a CBI claim for exemption regarding the concentration or actual concentration range of an ingredient under the HMIRA. It must be noted that once the hazardous product is imported, if the importer wants to sell the same product (or a mixture containing this product), they may use the "sale" exemption explained below, since they remain a subsequent supplier at that point.

Sale

This exemption may be used by any subsequent supplier (including the importer mentioned above) who wants to sell in Canada the same hazardous product (or a mixture containing this hazardous product) for which a CBI claim for exemption regarding the concentration or actual concentration range of an ingredient under the HMIRA was granted to the "first supplier" (Canadian or foreign). It is important to note that any downstream supplier in the distribution chain who sells the same hazardous product (or a mixture containing this hazardous product) in Canada is also a subsequent supplier and, as such, may use this exemption.

Conditions

As explained above, subsection 5.7(8) of the HPR allows the subsequent supplier to withhold the same information elements from the SDS, and label if applicable, that were the subject of a valid claim for exemption by the first supplier. Subsection 5.7(8) relates specifically to ingredient concentration information that is CBI. In order to qualify for this exemption, this information element must not be known to the subsequent supplier, or the subsequent supplier must have obtained the information in confidence and is obligated to maintain the confidentiality of the information. The subsequent supplier may sell the hazardous product mixture as is or may sell a new mixture which contains the first supplier's hazardous product mixture (as an ingredient); in both situations the same exemption applies. It is important to note that the supplier is still responsible for ensuring that the product is accurately classified, even if the ingredients of the first supplier's product are not known to the subsequent supplier.

Where the subsequent supplier was granted their own claim for CBI exemption under the HMIRA, the requirements for replacement information depend on what information the subsequent supplier has claimed for exemption. In this case, discussion about the particular case with Health Canada is recommended.

Where the subsequent supplier was not granted a claim for CBI exemption under the HMIRA, the replacement information of the first supplier namely,

• the first supplier's claim registry number
• the date when the first supplier's claim granted
• a statement that a claim for exemption has been granted and
• the concentration or concentration range of the first supplier's hazardous product mixture that is in the subsequent supplier's hazardous product mixture

must appear on the SDS provided by the subsequent supplier, along with the words "other supplier/autre fournisseur" in parentheses next to the first supplier's replacement information.

For example, suppose the first supplier's mixture contains the following 3 ingredients:

• ingredient A, a hazardous ingredient present at 5%, and this information is CBI
• ingredient B, a hazardous ingredient present at 20% (not CBI) and
• ingredient C, a non-hazardous ingredient present at 75%

The first supplier sells this mixture to a subsequent supplier, who dilutes the mixture with water in a ratio of 1:1. Therefore, the subsequent supplier's SDS need not disclose the concentration of ingredient A in the diluted mixture (since this information is CBI). However, the subsequent supplier's SDS for the diluted mixture must disclose the first supplier's claim registry number, the date when the first supplier's claim was granted, and the words "other supplier/autre fournisseur" in parentheses, and must state that the diluted mixture contains, at a concentration of 50%, another mixture (that is, the mixture of the first supplier).

In the above example, suppose the subsequent supplier sells the first supplier's mixture as is (without modification). In this case, the subsequent supplier's SDS must disclose the first supplier's claim registry number, the date when the first supplier's claim was granted, and the words "other supplier/autre fournisseur" in parentheses, and must state that the hazardous product is comprised, at 100%, of another mixture (that is, the mixture of the first supplier).

Discussion of subsection 5.7(9) of the Hazardous Products Regulations

Subsection 5.7(9) of the HPR applies to situations where federally or provincially regulated employers were granted claims for CBI under the HMIRA, or have availed themselves of their respective provincial laws pertaining to trade secrets to be exempt from the disclosure of the supplier's product identifier. This provision exempts the supplier, who sells hazardous products to these employers, from providing the product identifier (defined in subsection 1(1) of the HPR) on the label and SDS of the hazardous product for which CBI or a trade secret has been claimed by the employer.

However, the following information must be provided on the label:

1. a code name or a code number specified by the supplier, that replaces the product identifier and
2. the replacement information referred to in subsection 5.7(3) or (4) of the HPR regarding the claim for exemption under the HMIRA (that is, the registry number, the date the exemption was granted and a statement that a claim for exemption has been granted)

However, if such replacement information is not available (because the employer availed themself of trade secret provisions in OHS provincial or territorial legislation), then the replacement information required under the OHS legislation of the province or territory where the employer is located must be disclosed.

Discussion of subsection 5.7(10) of the Hazardous Products Regulations

Subsection 5.7(10) of the HPR applies to situations where federally or provincially regulated employers were granted claims for CBI under the HMIRA, or have availed themselves of their respective provincial laws pertaining to trade secrets to be exempt from the disclosure of any information that could be used to identify the supplier of the hazardous product. This provision exempts the supplier, who sells hazardous products to these employers, from providing information identifying the supplier including the initial supplier identifier (defined in subsection 1(1) of the HPR) on the label and SDS of the hazardous product for which CBI or a trade secret has been claimed by the employer.

On the label and SDS, the initial supplier identifier must be changed to the replacement information regarding the claim for exemption under the HMIRA referred to in subsections 5.7(3) or (4) of the HPR (that is, the registry number, the date the exemption was granted and a statement that a claim for exemption has been granted). If such replacement information is not available (because the employer availed themself of trade secret provisions in OHS provincial or territorial legislation), then the information required under the OHS legislation of the province or territory where the employer is located must be disclosed instead.

Discussion of subsection 5.7(11) of the Hazardous Products Regulations

Subsection 5.7(11) applies to situations where federally or provincially regulated employers were granted claims for CBI under the HMIRA, or have availed themselves of their respective provincial laws pertaining to trade secret to be exempt from the disclosure of any information that could be the subject of a claim under subsection 11(2) of the HMIRA. This provision exempts the supplier, who sells hazardous products to these employers, from providing on the SDS the information for which CBI or trade secret has been claimed by the employer.

Subsection 5.7(11) refers to employers claims under subsection 11(2) of HMIRA, this provision reads as follows:

Hazardous Materials Information Review Act

Subsection 5.7(11) specifies that any information element(s) that may be protected under HMIRA is not required to appear on the supplier's SDS of a hazardous product sold to an employer provided that:

1. (a) The employer is exempt under the HMIRA or the provincial or territorial OHS legislation from the requirement to disclose the information element(s) and
2. (b) The SDS provides the replacement information, as referred to in subsections 5.7(3) or (4) of the HPR, for the employer's CBI claim for exemption

However, if such replacement information is not available, the following must be disclosed in its place: An emergency telephone number of the employer to enable a health professional to obtain information that must be provided in the SDS, and which is in possession of the employer, for the purpose of making a medical diagnosis or rendering medical treatment, in an emergency.

Discussion of subsection 5.8(1) of the Hazardous Products Regulations

Under the HPR, the initial supplier identifier (name, address and telephone number of either the Canadian manufacturer or Canadian importer) must be provided on the SDS. Further information regarding "initial supplier identifier" is available in Part 1 of this guidance. This provision exempts a distributor (a Canadian supplier to whom a hazardous product was sold) from providing the initial supplier identifier on the SDS if the distributor provides their own name, address and telephone number instead.

Since this exemption only applies in a situation where a Canadian distributor is selling a hazardous product, the use of this exemption still requires the disclosure of the contact information of a Canadian party on the SDS.

It is important to note that according to section 4.2 of the HPR (Identical identifiers), the initial supplier identifier must be identical on the label and the SDS; thus, if the distributor takes advantage of the exemption in subsection 5.8(1) to replace the information on the SDS, they must also, according to subsection 5.8(2), replace the initial supplier identifier on the label.

Discussion of subsection 5.8(2) of the Hazardous Products Regulations

Under the HPR, the initial supplier identifier (name, address and telephone number of either the Canadian manufacturer or Canadian importer) must be provided on the label. This provision exempts a distributor (a Canadian supplier to whom a hazardous product was sold) from providing the initial supplier identifier on the label if the distributor provides their own name, address and telephone number instead.

Since this exemption only applies in a situation where a Canadian distributor is selling a hazardous product, the use of this exemption still requires the disclosure of the contact information of a Canadian party on the label.

It is important to note that according to section 4.2 of the HPR (Identical identifiers), the initial supplier identifier must be identical on the label and the SDS; thus, if the distributor takes advantage of the exemption in subsection 5.8(2) to replace the information on the label, they must also, according to subsection 5.8(1), replace the initial supplier identifier on the SDS.

Discussion of subsection 5.8(3) of the Hazardous Products Regulations

Under the HPR, the initial supplier identifier (name, address and telephone number of either the Canadian manufacturer or Canadian importer) must be provided on the label and SDS. This provision exempts a downstream distributor (a downstream Canadian supplier to whom a hazardous product was sold by an upstream Canadian distributor) from providing the initial supplier identifier on the label and SDS, if the distributor provides their own name, address and telephone number instead.

Since this exemption only applies in a situation where a hazardous product is being sold by a downstream Canadian distributor, the use of this exemption still requires the disclosure of the contact information of a Canadian party on the label and SDS.

It is important to note that according to section 4.2 of the HPR (Identical identifiers), the initial supplier identifier must be identical on the label and the SDS; thus, if the distributor takes advantage of the exemption in subsection 5.8(3) to replace the information on the label or SDS, they must replace the initial supplier identifier on both the label and the SDS.

Discussion of subsection 5.9(1) of the Hazardous Products Regulations

Under the HPR, the initial supplier identifier (name, address and telephone number of either the Canadian manufacturer or Canadian importer) is required under item 1(d) of the SDS. However, if an importer imports a hazardous product for use in their own work place, the importer may retain the foreign supplier's name, address and telephone number under item 1(d) of the SDS.

The Canadian importer who prepares the SDS for the hazardous product that they imported cannot use this exemption since it is limited to situations where the SDS is obtained from the foreign supplier. It is also important to note that the importer cannot use this exemption if they decide to resell the hazardous product that they imported. If the Canadian importer is reselling the hazardous product, then the Canadian importer's name, address and telephone number must be provided on the SDS.

Where a foreign supplier sells and ships a hazardous product directly to a Canadian customer, that Canadian customer is the Canadian importer. The Canadian importer is responsible for ensuring that the label and SDS of the hazardous product comply with the requirements of the HPA and the HPR.

In any case, it would be acceptable for the SDS to include the contact information of both the Canadian importer and the foreign supplier.

To further clarify, when a hazardous product is imported into Canada, the name, address and telephone number of a foreign manufacturer who does not have a place of business in Canada cannot be provided under item 1(d) of the SDS unless:

• the hazardous product is only used in the importer's own workplace or
• the name, address and telephone number of the Canadian importer is also provided

Discussion of subsection 5.9(2) of the Hazardous Products Regulations

Under the HPR, the initial supplier identifier (name, address and telephone number of either the Canadian manufacturer or Canadian importer) must be provided on the label. However, if an importer imports a hazardous product for use in their own work place, the importer may retain the foreign supplier's name, address and telephone number on the label.

It is important to note that the importer cannot use this exemption if they decide to resell the hazardous product that they imported. If the Canadian importer is reselling the hazardous product, then the Canadian importer's name, address and telephone number must be provided on the label.

Where a foreign supplier sells and ships a hazardous product directly to a Canadian customer, that Canadian customer is the Canadian importer. The Canadian importer is responsible for ensuring that the label and SDS of the hazardous product comply with the requirements of the HPA and the HPR.

In any case, it would be acceptable for the label to include the contact information of both the Canadian importer and the foreign supplier.

To further clarify, when a hazardous product is imported into Canada, the name, address and telephone number of a foreign manufacturer who does not have a place of business in Canada cannot be provided on the label unless:

• the hazardous product is only used in the importer's own workplace
• the name, address and telephone number of the Canadian importer is also provided or
• the importer takes advantage of the exemption in section 5.15 (refer to section 5.15 of this guidance for more information)

Discussion of section 5.10 of the Hazardous Products Regulations

This provision must be read in conjunction with paragraph 5.2(b) which specifies that a HPR label is not required on the outer container of a hazardous product that has a label which meets the requirements set out in the Transportation of Dangerous Goods Regulations. Therefore, section 5.10 only addresses situations where a label is provided on the hazardous product or on a single container (without inner or outer container) in which the hazardous product is packaged.

Where a hazardous product is packaged in a single container which does not meet the definition of a bulk shipment (subsection 5.5(1) of the HPR), and the single container is used for shipping the hazardous product, both the TDGR and HPR labels are required on the single container. An example of such a single container is a drum of solvent of less than 450 L. However, if the single container bears a label in accordance with the TDGR and the TDGR label includes a hazard symbol that is also required under the HPR, the pictogram with the same hazard symbol need not appear on the HPR label of the single container.

It is important to note that this labelling exemption in 5.10 can only be used if the TDGR label meets the durability requirement of section 3.5 of the HPR.

It is also important to note that instead of pictogram, the term "symbol" is used in section 5.10 because TDG labels do not include pictograms as defined in the HPR. The TDGR labels include symbols as defined in the HPR, in a shape that also includes numbers, background colors and patterns.

This labelling exemption is only for the HPR pictograms. Any signal word, hazard statement(s) or precautionary statement(s) that are required according to the HPR must be provided on the label, unless another exemption applies.

Discussion of section 5.11 of the Hazardous Products Regulations

Paragraph 5.11(a) of the HPR specifies that a separate SDS is not required to be provided by the supplier for every single container of the same hazardous product (that is, a product bearing the same product identifier) in a shipment sold to a customer. Therefore, if 300 bottles of the same hazardous product are shipped to a customer, only one compliant and up-to-date SDS must be provided by the supplier on the sale to the customer.

Paragraph 5.11(a) also applies to importation and specifies that a separate SDS is not required to be obtained or prepared by the importer, on or before the importation, for every single container of the same hazardous product (that is, a product bearing the same product identifier) in a shipment that is imported by an importer. Therefore, if 300 bottles of the same hazardous product are imported by an importer, only one compliant and up-to-date SDS must be obtained or prepared, on or before the importation, by the importer.

Paragraph 5.11(b) specifies that an SDS is not required to be provided upon every sale of the same hazardous product (that is, a product bearing the same product identifier) to the same customer, if the SDS that was most recently provided to the customer remains compliant with the HPR. Therefore, if 300 bottles of the same hazardous product are shipped by the same supplier to the same customer every month, it is not necessary for the supplier to provide an SDS with every shipment to that customer as long as the SDS that was initially provided remains up-to date and compliant with the HPR.

Paragraph 5.11(b) also applies to importation and specifies that an SDS is not required to be obtained or prepared, on or before importation, of the same hazardous product (that is, a product bearing the same product identifier) from the same foreign supplier, if the SDS that was most recently obtained or prepared by the importer remains compliant with the HPR. Therefore, if 300 bottles of the same hazardous product are imported by the same importer from the same foreign supplier every month, it is not necessary that the importer obtain or prepare an SDS, on or before importation, as long as the SDS that was initially obtained or prepared remains up-to date and compliant with the HPR.

Where significant new data (SND), as defined in subsection 5.12(1), become available within 90 days prior to sale, the supplier is allowed, during this period, to provide to their customer, at the time of sale, the current SDS (with the exception of the SND) and, in writing, the information required in paragraph 5.12(2)(b) (that is, the SND and the date that it became available) instead of immediately providing an updated SDS. In addition, as per paragraph 5.11(b), if further shipments of the same hazardous product (same product identifier) to the same customer are made within the above mentioned 90-day period of the date when the SND became available, it is not necessary to provide another SDS or to provide another document containing the SND that was already provided to that customer. However, once the 90-day period after the date when the SND became available expires, the supplier must, at the time of the sale, provide to the customer a new updated SDS that includes the SND.

In the case of import, if the next importation of the same hazardous product occurs within 90 days of the date when the SND became available, then the importer must obtain or prepare on or before the importation, the information required in paragraph 5.12(2)(b) (that is, the SND and the date that it became available). If further importation of the same hazardous product from the same foreign supplier are made within the 90-day period of the date when the SND became available, it is not necessary for the importer to obtain or prepare on or before the importation, another SDS or another document containing the SND that was already obtained or prepared by the importer. However, once the 90-day period after the date when the SND became available expires, the importer must, on or before importation, obtain or prepare a new updated SDS that includes the SND.

Discussion of subsections 5.12(1) and (2) of the Hazardous Products Regulations

The SDS provided by a supplier upon the sale of a hazardous product, as required by paragraph 13(1)(a.1) of the HPA, must comply with all applicable requirements of the HPR. This requirement means that the hazardous product must be appropriately classified based on all data available at the time of sale to determine which information elements must be provided on the SDS. In the event where SND become available to the supplier within 90 days prior to the sale of the hazardous product, subsection 5.12(2) provides an exemption from having to update any information element(s) on the SDS during those 90 days, as long as the person or government that acquires possession or ownership of the product is provided with a document with the changes to the safety data sheet that are required as a result of the SND and the date on which the SND became available.

It is important to note that subsection 5.12(2) is not an exemption from having to provide required information about a hazardous product at the time of sale of that product, but rather a provision which permits the information to be provided in a format additional to the SDS.

The term "significant new data" as defined in paragraph 5.12(1) of the HPR means any new data regarding the hazards presented by a hazardous product that changes the classification of the product (category or subcategory of a hazards class or another hazard class), or changes the way to protect against the hazards presented by the product.

In practice, the SND that must be provided by the supplier to the recipient of a hazardous product in the context of subsection 5.12(2) consists of a list of all the changes to the classification of the hazardous product, the data under items 9, 10 and 11 of the SDS that lead to the change in the classification and a list of all the changes to the ways of protecting against the hazard of the product (that is, the information elements of the SDS that are being changed and what those information elements are being changed to, as the result of the SND).

As per subsection 5.12(2) of the HPR, during the 90-day exemption period, until the SDS is updated to reflect the SND, the SND must be provided on a separate document (see the definition of "document" in section 2 of the HPA), and the separate document must also provide the date on which the SND became available. The requirement to provide the document could be met through an email to the purchaser of the hazardous product as long as the email is received by the purchaser at the time of the sale.

If the SND became available more than 90 days prior to the sale of the hazardous product (for example 98 days prior to the sale), then subsection 5.12(2) is not applicable, and the supplier must, upon the sale of the hazardous product, provide to the purchaser a new updated SDS that incorporates the SND. Of course, the supplier may also update their SDS at any time during the 90-day period mentioned in subsection 5.12(2). If the supplier has the updated SDS completed within less than 90 days, the written notice is no longer required to be provided, so long as the updated SDS is provided. Once 90 days have passed since the SND became available, for any sales of the hazardous product that take place after that date, the updated SDS must be provided.

It must be noted that the content of the document required pursuant to paragraph 5.12(2)(b) (SND and the date on which the SND became available) and the content of the document required under paragraph 5.12(4)(b) (SND in the context of labelling requirements) could be provided in one document in addition to the SDS.

As the HPA requires the provision of all relevant required information relating to a hazardous product, based on data available at the time of sale, suppliers must be vigilant and seek any new information related to their hazardous products in order to determine if the classification of their hazardous products or the ways to protect against the hazard(s) presented by the hazardous products are affected.

In a situation where the exemption set out in subsection 5.12(2) is used, the document required under paragraph 5.12(2)(b) must be provided in both official languages.

Discussion of subsection 5.12(3) of the Hazardous Products Regulations

The SDS that a supplier who is an importer must obtain or prepare on or before importation of a hazardous product, as required by paragraph 14(a) of the HPA, must comply with all applicable requirements of the HPR. This requirement means that the hazardous product must be appropriately classified based on all data available on or before importation to determine which information elements must be provided on the SDS. In the event where SND become available to the importer within 90 days prior to the importation of the hazardous product, subsection 5.12(3) of the HPR provides an exemption from having to update any information element(s) on the SDS during those 90 days, as long as the importer obtains or prepares a document that provides the changes to the safety data sheet that are required as a result of the significant new data and the date on which the significant new data became available and appends that document to the safety data sheet referred to in paragraph 5.12(3)(a).

It should be noted that the exemption in subsection 5.12(3) only applies to an importer who has obtained the SDS, and not to an importer who has prepared the SDS.

It is important to note that subsection 5.12(3) is not an exemption from having to obtain required information about a hazardous product on or before importation of that product, but rather a provision which permits the information to be provided in a format additional to an SDS that has been obtained.

The term "significant new data" as defined in paragraph 5.12(1) of the HPR means any new data regarding the hazards presented by a hazardous product that changes the classification of the product (category or subcategory of a hazards class or another hazard class), or changes the way to protect against the hazards presented by the product.

In practice, the SND that must be obtained or prepared by the supplier (importer) of a hazardous product in the context of subsection 5.12(3) consists of a list of all the changes to the classification of the hazardous product, the data under items 9, 10 and 11 of the SDS that leads to the change in the classification and a list of all the changes to the ways of protecting against the hazard of the product (that is, the information elements of the SDS that are being changed and what those information elements are being changed to, as the result of the SND).

As per subsection 5.12(3), during the 90-day exemption period, until the obtained SDS is updated to reflect the SND, the changes to the safety data sheet that are required as a result of the SND must be obtained or prepared on a separate document (see the definition of "document" in section 2 of the HPA), and the separate document must also provide the date on which the SND became available.

If the SND became available more than 90 days prior to importation of the hazardous product (for example 98 days prior to importation), then subsection 5.12(3) is not applicable, and the importer must, on or before importation of the hazardous product, obtain or prepare a new updated SDS that incorporates the SND. Of course, the supplier (importer) may also obtain or prepare an updated SDS at any time during the 90-day period mentioned in subsection 5.12(3). If the supplier (importer) has the updated SDS completed within less than 90 days, the written notice is no longer required to be provided, so long as the updated SDS is provided. Once 90 days have passed since the SND became available, for any sales of the hazardous product that take place after that date, the updated SDS must be provided.

It must be noted that the content of the document required pursuant to paragraph 5.12(3)(b) (changes to the SDS and the date on which the SND became available) and the content of the document required under paragraph 5.12(5)(b) (changes to the label as a result of the SND) could be provided in one document in addition to the SDS.

As the HPA requires the provision of all relevant required information relating to a hazardous product, based on data available at the time of sale, suppliers must be vigilant and seek any new information related to their hazardous products in order to determine if the classification of their hazardous products or the ways to protect against the hazard(s) presented by the hazardous products are affected.

In a situation where the exemption set out in subsection 5.12(3) is used, the document required under paragraph 5.12(3)(b) must be obtained or prepared in both official languages.

Discussion of subsection 5.12(4) of the Hazardous Products Regulations

The label provided by a supplier upon the sale of a hazardous product, as required by paragraph 13(1)(b) of the HPA, must comply with all applicable requirements of the HPR. This requirement means that the hazardous product must be appropriately classified based on all data available at the time of sale to determine which information elements must be provided on the label. In the event where SND become available to the supplier within 180 days prior to the sale of the hazardous product, subsection 5.12(4) of the HPR provides an exemption from having to update any information element(s) on the label during those 180 days, as long as the person or government that acquires possession or ownership of the product is provided with a document with the changes to the label that are required as a result of the SND and the date on which the SND became available.

It is important to note that subsection 5.12(4) is not an exemption from having to provide required information about a hazardous product at the time of sale of that product, but rather a provision which permits the information to be provided in a format additional to the label.

The term "significant new data" as defined in paragraph 5.12(1) of the HPR means any new data regarding the hazards presented by a hazardous product that changes the classification of the product (category or subcategory of a hazards class or another hazard class), or changes the way to protect against the hazards presented by the product.

In practice, the SND that must be provided by the supplier to the recipient of a hazardous product in the context of subsection 5.12(4) consists of a list of all the changes to the classification of the hazardous product and a list of all the changes to the ways of protecting against the hazard of the product (that is, the information elements of the label that are being changed and what those information elements are being changed to, as the result of the SND).

As per subsection 5.12(4), during the 180-day exemption period, until the label is updated to reflect the SND, the changes to the label that are required as a result of the SND must be provided on a separate document (see the definition of "document" in section 2 of the HPA), and the separate document must also provide the date on which the SND became available. The requirement to provide the document could be met through an email to the purchaser of the hazardous product as long as the email is received by the purchaser at the time of the sale.

If the SND became available more than 180 days prior to the sale of the hazardous product (for example 188 days prior to the sale), then subsection 5.12(4) is not applicable. The supplier must, upon the sale of the hazardous product, ensure that the hazardous product or the container in which the hazardous product is packaged has a new updated label that incorporates the SND, affixed to it, printed on it or attached to it in a manner that meets the requirements of the HPR. Of course, the supplier may also update their label at any time during the 180-day period mentioned in subsection 5.12(4). If the supplier has the updated label completed within less than 180 days, the written notice is no longer required to be provided, so long as the updated label is provided. Once 180 days have passed since the SND became available, for any sales of the hazardous product that take place after that date, the updated label must be provided.

It must be noted that the content of the document required pursuant to paragraph 5.12(4)(b) (changes to the label and the date on which the SND became available) and the content of the document required under paragraph 5.12(2)(b) of the HPR (changes to the SDS as a result of the SND) could be provided in 1 document along with the label.

As the HPA requires the provision of all relevant required information relating to a hazardous product, based on data available at the time of sale, suppliers must be vigilant and seek any new information related to their hazardous products in order to determine if the classification of their hazardous products or the ways to protect against the hazard(s) presented by the hazardous products are affected.

In a situation where the exemption set out in subsection 5.12(4) is used, the document required under paragraph 5.12(3)(b) must be provided in both official languages.

Discussion of subsection 5.12(5) of the Hazardous Products Regulations

As required by paragraph 14(b) of the HPA, a supplier (who is an importer) of a hazardous product must ensure that the hazardous product or the container in which the hazardous product is packaged has an HPR compliant label affixed to it, printed on it or attached to it in a manner that meets the requirements of the HPR. This requirement means that the hazardous product must be appropriately classified based on all data available on or before importation to determine which information elements must be provided on the label. In the event where SND become available to the importer within 180 days prior to the importation of the hazardous product, subsection 5.12(5) of the HPR provides an exemption from having to update any information element(s) on the label during those 180 days, as long as the importer obtains or prepares a document that provides the changes to the label that are required as a result of the significant new data and the date on which the significant new data became available and appends that document to the safety data sheet referred to in paragraph 5.12(5)(a).

It should be noted that the exemption in subsection 5.12(5) only applies to an importer who has imported a product already labelled. It would not apply to any importer making use of the exemption set out in section 5.15 of the HPR to import a product that is not labelled in compliance with the HPR, for the purpose of bringing it into compliance before sale or use.

It is important to note that subsection 5.12(5) of the HPR is not an exemption from having to obtain required information about a hazardous product on or before importation of that product, but rather a provision which permits the information to be provided in a format additional to an existing label.

The term "significant new data" as defined in paragraph 5.12(1) of the HPR means any new data regarding the hazards presented by a hazardous product that changes the classification of the product (category or subcategory of a hazards class or another hazard class), or changes the way to protect against the hazards presented by the product.

In practice, the SND that must be obtained or prepared by the supplier (importer) of a hazardous product in the context of subsection 5.12(5) of the HPR consists of a list of all the changes to the classification of the hazardous product and a list of all the changes to the ways of protecting against the hazard of the product (that is, the information elements of the label that are being changed and what those information elements are being changed to, as the result of the SND).

As per subsection 5.12(5) of the HPR, during the 180-day exemption period, until the existing label is updated to reflect the SND, the changes to the safety data sheet that are required as a result of the SND must be obtained or prepared on a separate document (see the definition of "document" in section 2 of the HPA), and the separate document must also provide the date on which the SND became available.

If the SND became available more than 180 days prior to importation of the hazardous product (for example 188 days prior to importation), then subsection 5.12(5) of the HPR is not applicable. The importer must ensure that the hazardous product or the container in which the hazardous product is packaged has a new updated label that incorporates the SND, affixed to it, printed on it or attached to it in a manner that meets the requirements of the HPR. Of course, the supplier (importer) may also do this at any time during the 180-day period mentioned in subsection 5.12(5). If the supplier (importer) has the updated label completed within less than 180 days, the written notice is no longer required to be provided, so long as the updated label is provided. Once 180 days have passed since the SND became available, for any sales of the hazardous product that take place after that date, the updated label must be provided.

It must be noted that the content of the document required pursuant to subsection 5.12(5) of the HPR (SND in the context of label requirements) and the content of the document required under subsection 5.12(3) (SND in the context of SDS requirements) could be obtained or prepared in one document in addition to the SDS.

As the HPA requires the provision of all relevant required information relating to a hazardous product, based on data available at the time of sale, suppliers must be vigilant and seek any new information related to their hazardous products in order to determine if the classification of their hazardous products or the ways to protect against the hazard(s) presented by the hazardous products are affected.

In a situation where the exemption set out in subsection 5.12(5) is used, the document required under paragraph 5.12(3)(b) must be obtained or prepared in both official languages.

Discussion of section 5.13 of the Hazardous Products Regulations

The term "bailment" referred to in this guidance document means the "transfer of possession without the transfer of ownership".

When a hazardous product is bailed for the purposes of transportation, the supplier is not required to provide an SDS to the bailee, for example, the driver of a delivery company, which is a third party, transporting the hazardous product. For example, when the driver of a delivery company, such as Canada Post, UPS, FedEx etc., is given a hazardous product by a supplier for delivery to a recipient, the supplier is not required to provide an SDS to the driver or the company they represent. This is because a bailment has occurred between the supplier and the delivery company, and as such the exemption in section 5.13 of the HPR is triggered.

However, the requirement for hazardous products to bear an HPR compliant label applies while they are being transported, unless an exemption under the HPR applies.

Discussion of subsections 5.14(1), (2) and (3) of the Hazardous Products Regulations

These exemptions from labeling and SDS requirements apply to importation (subsection 5.14(2) of the HPR) and sale, for the purposes of exportation (subsection 5.14(3) of the HPR), of hazardous products that are not meant to be used in a work place in Canada. Such hazardous products do not require an HPR compliant label or SDS. The regulation of hazardous products while in transit or being transported for exportation is under the authority of Transport Canada, under the Transportation of Dangerous Goods Act and Regulations. The "sale of hazardous products for the purpose of their exportation" applies to a Canadian supplier who sells a hazardous product to a foreign customer (export) or to a Canadian customer who intends to resell them to a foreign customer.

Note that, for the purpose of the exemption under subsection 5.14(2), the expression "use in a work place" in the context of hazardous products in transit excludes loading, unloading, packing, unpacking or storing of those products. This means that if a hazardous product in transit is loaded, unloaded, packed, unpacked or stored in a workplace, these activities must not be considered as "use in a workplace", and therefore this exemption applies.

Discussion of subsections 5.15(1) and (2) of the Hazardous Products Regulations

Subsections 5.15(1) and (2) of the HPR are labelling exemptions that allow an importer to import hazardous products without labels or with labels that do not comply with the HPR, provided that the intent of the importer is to re-label these hazardous products with HPR compliant labels before they are used or sold in Canada. It must be noted that these hazardous products must have fully compliant SDSs, which were either obtained or prepared, on or before importation, as there is no equivalent SDS exemption.

Upon the request of an inspector, the onus is on the importer to provide credible evidence to prove that the hazardous products are being brought into compliance with the labelling requirements of the HPR before they will be used or sold. Examples of credible evidence that may be requested by inspectors may include answers to these questions, or similar ones:

• Which printing company has been hired to produce the new compliant labels?
• Where is a draft label or mock-up of the label?
• Where is the work plan or schedule for completion of the necessary work?
• What measures are in place to prevent the use of the product prior to its relabelling?

Part 6 Additional requirements

Part 6 of the Hazardous Products Regulations (HPR) sets out additional requirements that relate to the information that must be provided on the safety data sheet (SDS) or label of a hazardous product. Notably, Part 6 requires that SDSs and labels always be in both official languages of Canada (English and French). In addition, suppliers must:

• provide information about the hazardous product to a health professional who requests that information for the purpose of making a medical diagnosis of, or rendering medical treatment to, an individual in an emergency.
• Subject to the Hazardous Materials Information Review Act (HMIRA), disclose the source of information for any toxicological data used in the preparation of an SDS, on the request of an inspector, any person or government to which the hazardous product is sold or any user of the hazardous product.

The following definitions from the Hazardous Products Act (HPA) are relevant to this Part of the Guidance:

Further information about these definitions can be found in the chapters relating to Part 1 (Interpretation), Part 3 (Labelling) and Part 4 (Safety Data Sheet).

Discussion of subsection 6(1) of the Hazardous Products Regulations

Any information element that is referred to in subsection 4(1) of the HPR, and that is in the possession of the supplier, must be provided by the supplier to a health professional (see the definition of health professional in subsection 1(3) of the HPR) upon request, provided that the health professional makes the request for the purpose of making a medical diagnosis of, or rendering medical treatment to, an individual in an emergency. The health professional must consider the requested information element to be necessary or useful to make a medical diagnosis of, or render a medical treatment to, an individual in an emergency. Section 29 of the HMIRA sets out a similar provision that pertains to confidential business information (CBI). For further information concerning this provision, please refer to Appendix A of this guidance.

A supplier who receives a request for information from a health professional should understand that there is an emergency situation in which an individual is in need of medical attention, and therefore, reasonable attempts should be made to comply with the request as soon as possible. When a supplier receives a request for information from a health professional, the supplier must provide all requested information elements in their possession. The requested information elements should be provided in any expedited fashion that is acceptable to the medical professional. Since the information elements provided on an SDS must be in both official languages of Canada (see section 6.2 of the HPR), the supplier must provide the required information elements in both official languages.

The nature and extent of the information required to appear on the SDS of a hazardous product pursuant to paragraph 4(1)(c) of the HPR (which refers to additional hazard information that is available) may provide health professionals with valuable information for the purpose of making a medical diagnosis or rendering medical treatment to an individual in an emergency.

Discussion of subsection 6(2) of the Hazardous Products Regulations

The objective of this provision is to provide a mechanism to preserve the confidentiality of information that is CBI and that was provided to a health professional by a supplier.

This provision addresses situations where a supplier has filed or was granted a claim for CBI under the Hazardous Materials Information Review Act (HMIRA), and the supplier receives a request from a health professional, through subsection 6(1) of the HPR, for an information element that is the subject of a claim. When the supplier provides the information, this provision requires that the health professional maintain the confidentiality of the information elements subject to a claim under HMIRA that were provided to the health professional, except for the purpose for which they were provided, so long as the health professional has been informed by the supplier that the information is to be kept confidential.

Discussion of section 6.1 of the Hazardous Products Regulations

Subject to the provisions of the HMIRA, a supplier who receives a request for the source of information for any toxicological data provided under item 11 (Toxicological Information) of the SDS from an inspector, any person or government to which a hazardous product is sold or any user of a hazardous product, must provide that information to the requester as soon as possible. There is no requirement under the HPR for the recipient of this information to maintain it in confidence.

However, paragraph 11(1)(c) of the HMIRA allows a supplier to file a claim for an exemption from the requirement to disclose, under item 11 of the SDS, the name of any toxicological study that identifies a material or substance that is a hazardous product, or any ingredient in a mixture that is a hazardous product, if the supplier considers this information to be CBI. In the event that a supplier has filed or was granted a CBI claim and receives a request for the source of information for any toxicological data provided under item 11 of the SDS, the supplier is lawfully allowed to refuse to disclose the sought information.

There are provisions under the HMIRA which, under certain circumstances, allow the Minister to disclose any information that is referred to in subsection 11(1) or (2) of the HMIRA and that is CBI. In the case of a material, substance or mixture that is a hazardous product, this includes the name of any toxicological study that identifies the material, substance, or any ingredient in the mixture. For further information concerning these provisions, please refer to Appendix A of this guidance.

Discussion of subsection 6.2(1) of the Hazardous Products Regulations

Subsection 6.2(1) of the HPR specifies that the information elements provided on an SDS and on a label must be in both official languages of Canada (English and French). It must be noted that this provision is required to fulfill an obligation under the Official Languages Act (OLA).

Discussion of paragraph 6.2(2)(a) of the Hazardous Products Regulations

The following are examples of ways in which the requirement for providing bilingual SDSs could be met:

1. The supplier could provide a single bilingual SDS, that is, an SDS that contains the required information elements, as set out in Part 4 and Schedule 1 of the HPR, in one document where the English and French text are interspersed.
2. The supplier could provide an SDS that contains the required information elements, as set out in Part 4 and Schedule 1 of the HPR, in 1 document where the English and French portions of the SDS are separated into 2 parts - 1 in English and 1 in French. Either all of the English text could appear first and then all of the French text, or vice versa.

Providing a bilingual SDS

A bilingual SDS must be provided to the purchaser of the hazardous product, either in hard copy (for example, by mail, by courier, hand delivered etc.) or by electronic means. An example of a way in which a bilingual SDS could be provided to a purchaser by electronic means is that a supplier could send an email to the purchaser and attach the SDS to the email. In the case where the English and French portions of the SDS are 2 separate parts, both the English and French parts must be attached to the same email.

It is important to note that there may be other ways in which bilingual SDSs may be provided to purchasers. It is also important to note that it is not acceptable to provide an SDS by only providing the purchaser of the hazardous product with a website address or hyperlink from which the purchaser may download the SDS for the hazardous product that they purchased. Similarly, it is not acceptable for a supplier to provide an SDS by only providing a QR code that would link the purchaser directly to the website or database from which the purchaser may download the SDS for the hazardous product that they purchased.

Discussion of paragraph 6.2(2)(b) of the Hazardous Products Regulations

Bilingual presentation (continued)

The following are examples of ways in which the requirement for bilingual labels can be met:

1. A single bilingual label, with the English and French text side by side or one above the other, or with the English and French text interspersed, is affixed to, printed on or attached to the hazardous product or the container in which the hazardous product is packaged.

An example of a side by side label is shown in Figure 13 below:

Figure 13 - Text description

An example of a single bilingual label, with the English and French text side by side, for a hazardous product. The label includes the product identifier at the top of the label, followed by the pictograms, signal word, hazard statements, precautionary statements and the initial supplier identifier at the bottom of the label.

2. The English and French portions of the label could be separated into 2 parts. The group of information elements for each part can be:

• affixed to
• printed on or
• attached to, including attached to same side of

the hazardous product or the container in which the hazardous product is packaged, either side-by-side or one on top of the other or any other configuration which contrasts with any other information on the hazardous product or the container

3. The English and French portions of the label could be separated into 2 parts. The group of information elements for each part can be:

• affixed to
• printed on or
• attached to, including attached to 2 different sides of the hazardous product or the container in which the hazardous product is packaged.

In this scenario, it may not be possible to see both English and French text all at once, if this is the case, the required pictogram(s) would be required to appear on each unilingual part of the label. This repetition would not be considered to contravene section 14.2 of the HPA.

Section 3.4 of the HPR requires that both the English and French portions of the label be placed on a surface that is visible under normal conditions of use. For example, if a hazardous product is packaged in a square bottle, the English portion of the label could be attached to one side of the bottle and the French portion, to any other side. The 2 sides need not be adjacent to one another, provided that each side of the bottle is visible under normal conditions of use, but not necessarily at the same time. Placing a portion of the label on the bottom of a container is not permitted. As mentioned previously, if the 2 unilingual parts of the label are located on 2 sides of the container that are opposed (consequently, not visible all at once), the required pictogram(s) would have to appear on each unilingual part of the label.

Irrespective of which option is chosen, the label must comply with the requirements of Part 3 of the HPR. Requirements with respect to legibility and durability are set out in sections 3.4 and 3.5 of the HPR, respectively.

References for this section of the guide (Hazardous Products Regulations – Part 6 Additional requirements)

• Hazardous Products Act, R.S.C., 1985, c. H-3
• Hazardous Products Regulations, SOR/2015-17

Part 7 Physical Hazard Classes

Introduction

Part 7 of this guidance provides an overview of the physical hazard classes and their classification, in general. Detailed guidance on each physical hazard class, as set out in Part 7 of the Hazardous Products Regulations (HPR), has been provided to assist suppliers in determining the appropriate hazard classification of a product, mixture, or substance, in relation to the criteria for physical hazards. Physical hazards are based on the physical or chemical properties of the product, such as flammability, reactivity or corrosivity. The physical hazards presented by a product, mixture or substance can cause harm to workers by exposing them to fire or explosion.

Classification in relation to the physical hazard classes is based on available data and no additional testing is required to be undertaken. However, if testing is carried out, then any test method(s) specified in the chapter for a given physical hazard must be applied. All available data must be evaluated against the criteria for each physical hazard class to determine the classification of a product, mixture or substance. It is important to note that the classification of a product, mixture or substance in 1 physical hazard class does not necessarily preclude classification of the same product, substance or mixture in other physical hazard classes.

The list of Physical Hazard classes in Schedule 2 of the Hazardous Products Act (HPA) is the following:

1. Explosives ^{Footnote 1}
2. Flammable Gases
3. Aerosols
4. Oxidizing Gases
5. Gases under Pressure
6. Flammable Liquids
7. Flammable Solids
8. Self-reactive Substances and Mixtures
9. Pyrophoric Liquids
10. Pyrophoric Solids
11. Self-heating Substances and Mixtures
12. Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases
13. Oxidizing Liquids
14. Oxidizing Solids
15. Organic Peroxides
16. Corrosive to Metals
17. Combustible Dusts ^{Footnote 2}
18. Simple Asphyxiants ^{Footnote 2}
19. [Repealed, SOR/2022-273, s. 2] ^{Footnote 3}
20. Physical Hazards Not Otherwise Classified ^{Footnote 2}
21. Chemicals Under Pressure ^{Footnote 4}

Notes:

The classification criteria for each of these 20 physical hazard classes are addressed by a Subpart of Part 7, set out in the same order as listed in Schedule 2 of the HPA.

Physical State

Certain physical hazards are based on physical state: gas, liquid and solid. Physical states are defined by their intrinsic properties. Physical properties such as melting point, boiling point and viscosity may be necessary to identify the physical state of the substance or mixture. In the definitions and classification criteria for the hazard classes set out in Parts 7 and 8 of the HPR, where no mention is made with regard to physical state, it must be understood that the hazard class applies to all physical states. The following physical state definitions are included in subsection 1(1) of Part 1 of the HPR: gas; liquid; and solid.

Physical State and Physical Hazard Class

The physical states that are addressed by the various physical hazard classes are shown in the following table:

Table 7.1 Summary – Physical states that are addressed by the various physical hazard classes.

Hazard Class	Gas	Liquid	Solid
7.2 Flammable Gases	Yes	No	No
7.3 Aerosols	Yes	Yes	Yes
7.4 Oxidizing Gases	Yes	No	No
7.5 Gases Under Pressure	Yes	No	No
7.6 Flammable Liquids	No	Yes	No
7.7 Flammable Solids	No	No	Yes
7.8 Self-Reactive Substances and Mixtures	No	Yes	Yes
7.9 Pyrophoric Liquids	No	Yes	No
7.10 Pyrophoric Solids	No	No	Yes
7.11 Self-Heating Substances and Mixtures	No	Yes	Yes
7.12 Substances and Mixtures which, in Contact With Water, Emit Flammable Gases	No	Yes	Yes
7.13 Oxidizing Liquids	No	Yes	No
7.14 Oxidizing Solids	No	No	Yes
7.15 Organic Peroxides	No	Yes	Yes
7.16 Corrosive to Metals	No	Yes	Yes
7.17 Combustible Dusts	No	No	Yes
7.18 Simple Asphyxiants	Yes	No	No
7.19 [Repealed, SOR/2022-272, s. 36]	Not applicable	Not applicable	Not applicable
7.20 Physical Hazards Not Otherwise Classified	Yes	Yes	Yes
7.21 Chemicals Under Pressure	No	Yes	Yes

Types of data that can be used to classify a product, mixture or substance in the physical hazard classes

When classifying a product or substance with respect to the physical hazard classes set out in Part 7 of the HPR, certain types of data are to be used, as specified in subparagraphs 2.1(a)(i) to (i)(v) and 2.1(b)(i) to (iv) of the HPR.

Data on the product or substance may include any of the following:

• results of testing or studies carried out in accordance with the test methods referred to in Part 7;
• results of testing or studies carried out in accordance with generally accepted standards of good scientific practice;
• conclusions based on established scientific principles; and
• case reports or documented

If data on the product or substance itself are unavailable or are insufficient to evaluate the substance or material in accordance with the applicable criteria, then for each physical hazard class, data of the types listed above for a product or substance with similar properties to the substance or material that is being classified must be considered.

Further guidance is provided in the discussion of section 2.1 in Part 2 of this guidance.

When classifying a mixture with respect to the physical hazard classes set out in Part 7 of the HPR, the types of data to be used are the same as those listed above. The data may pertain to the mixture as a whole or a mixture with similar properties, as specified in subsection 2.2(1) of the HPR. Further guidance is provided in the discussion of subsection 2.2(1) in Part 2 of this guidance.

Specific consideration that is relevant to the physical hazard classification of a product, mixture, or substance (section 2.8 of the HPR)

In the case of certain physical hazard classes, namely, Flammable Solids (Subpart 7 of Part 7), Pyrophoric Solids (Subpart 10 of Part 7), Self-Heating Substances and Mixtures (Subpart 11 of Part 7), Substances and Mixtures Which, in Contact With Water, Emit Flammable Gases (Subpart 12 of Part 7) and Oxidizing Solids (Subpart 14 of Part 7), the data used for the purposes of classification must relate to the solid in the physical form in which it is sold or imported. If the solid is in some other physical form that is different from the form in which the data was generated then the evaluation must be carried out in that other physical form of the solid. This is because different forms and physical states of a substance or mixture may result in different physical properties and hazards with possible consequences on the classification of the substance or mixture.

In addition to using information on the mixture itself or information on a mixture with similar properties, there are 4 physical hazard classes which include provisions for classifying mixtures based on information on the ingredients in the mixture.

1. In Subpart 2 of Part 7 (Flammable Gases), subsection 7.2.1 (3) allows the use of a calculation method to determine the flammability of a gas mixture. This method uses data on the ingredients to determine the flammability of the gas
2. In Subpart 4 of Part 7 (Oxidizing Gases), section 7.4.1 allows the use of a calculation method to determine the oxidizing power of a gas mixture. This method uses data on the ingredients to determine the oxidizing power of the gas
3. In Subpart 6 of Part 7 (Flammable Liquids), paragraph 7.6.1 (4)(b) also refers to a calculation method which uses data on ingredients to determine the flammability of a liquid mixture.
4. In Subpart 15 of Part 7 (Organic Peroxides), subsections 7.15.1(4) and 7.15.1(5) do not use a calculation method but require, under certain conditions, that the classification of a mixture of organic peroxides be based on data available on the ingredients.

Test Procedures

The physical hazard classes may have specific test procedures associated with them, or a more general test method, or none at all.

Data from scientifically validated methods, developed by the International Organization for Standardization (ISO standard) or American Society for Testing Materials International (ASTM standard) can, and must in certain circumstances, be used for determining classification, as indicated in specific provisions of Part 7 of the HPR:

• Subpart 2: Flammable Gases: ISO standard 10156:2017: Gases and gas mixtures — Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets
• Subpart 4: Oxidizing Gases: ISO standard 10156:2017: Gases and gas mixtures — Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets
• Subpart 6: Flammable Liquids: any appropriate closed-cup ISO or ASTM method listed in paragraph 2.6.4.2.5 of the GHS (seventh revised edition, 2017) for testing the flash point of a liquid must be used as long as the liquid meets the criteria specified by the method in question.
• Certain hazard classes have no test methods associated with them:
• Subpart 5: Gases Under Pressure
• Subpart 17: Combustible Dusts
• Subpart 18: Simple Asphyxiants
• Subpart 20: Physical Hazards Not Otherwise Classified
• Subpart 21: Chemicals Under Pressure.

Test methods may become available in the future.

Many of the physical hazard classifications are based on United Nations (UN) Transport of Dangerous Goods criteria and the test procedures come from the UN Manual of Tests and Criteria, as amended from time to time. The Manual of Tests and Criteria contains criteria, test methods and procedures to be used for the classification of dangerous goods according to the provisions of Parts 2 and 3 of the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, as well as the classification of chemicals presenting physical hazards according to the GHS. Test procedures found in the Manual of Tests and Criteria are referred to in the following physical hazard classes in Part 7 of the HPR:

• Subpart 3: Aerosols
• Subpart 7: Flammable Solids
• Subpart 8: Self-reactive Substances and Mixtures
• Subpart 9: Pyrophoric Liquids
• Subpart 10: Pyrophoric Solids
• Subpart 11: Self-heating Substances and Mixtures
• Subpart 12: Substances and Mixtures Which in Contact with Water, Emit Flammable Gases
• Subpart 13: Oxidizing Liquids
• Subpart 14: Oxidizing Solids
• Subpart 15: Organic Peroxides
• Subpart 16: Corrosive to Metals

Exclusions

For many of the hazard classes set out in Part 7 of the HPR, there are "exclusion(s)" provisions that indicate specific products, mixtures and/or substances that need not or must not be classified in any category of that specific hazard class. The following is a summary of the exclusions that appear in Part 7 of the HPR. In the table below the exclusions are listed by hazard class, and the text of the exclusions aligns with the language in the HPR with the exception of the "Exclusion after evaluation" provisions.

Table 7.2 Summary – Exclusions that appear in Part 7 of the HPR; listed with their respective hazard class.

Subpart	Hazard class	Exclusion(s)
2	Flammable Gases	Any product that is classified in a category of the hazard class "Aerosols" need not be classified in any category of this hazard class. Any product that is classified in a category of the hazard class "Chemicals Under Pressure" must not be classified in any category or subcategory of this hazard class".
3	Aerosols	Any product that is classified in a category of the hazard class "Chemicals Under Pressure" must not be classified in any category of this hazard class.
5	Gases Under Pressure	Any product that is classified in a category of the hazard class "Aerosols" need not be classified in any category of this hazard class. Any product that is classified in a category of the hazard class "Chemicals Under Pressure" must not be classified in any category of this hazard class.
6	Flammable Liquids	Any product that is classified in a category of the hazard class "Aerosols" need not be classified in any category of this hazard class. Any product that is classified in a category of the hazard class "Chemicals Under Pressure" must not be classified in any category of this hazard class.
7	Flammable Solids	Any product that is classified in a category of the hazard class "Aerosols" need not be classified in any category of this hazard class. Any product that is classified in a category of the hazard class "Chemicals Under Pressure" must not be classified in any category of this hazard class.
8	Self-reactive Substances and Mixtures	The following need not be classified in any category of this hazard class: mixtures or substances, or mixtures or substances as packaged, that are classified in a category of the hazard class "Organic Peroxides" liquid or solid mixtures that are classified in a category of the hazard class "Oxidizing Liquids" or "Oxidizing Solids", and contain less than 5.0% of combustible organic substances; and liquid or solid substances that are classified in a category of the hazard class "Oxidizing Liquids" or "Oxidizing Solids". After evaluation, a mixture or substance with a self-accelerating decomposition temperature greater than 75°C when evaluated in a 50 kg package.
11	Self-heating Substances and Mixtures	The following need not be classified in any category of this hazard class: a liquid classified in the category of the hazard class "Pyrophoric Liquids"; and a solid classified in the category of the hazard class "Pyrophoric Solids". After evaluation, a mixture or substance with a temperature of spontaneous combustion higher than 50°C for a volume of 27 m3.
12	Substances and Mixtures Which in Contact with Water, Emit Flammable Gases	The following liquids or solids need not be classified in any category of this hazard class: those that have a chemical structure that does not contain metals or metalloids; those that have been shown, through accumulated experience in production or handling, not to react with water; and those that are soluble in water to form a stable mixture.
13	Oxidizing Liquids	The following liquids need not be classified in any category of this hazard class: any organic liquid that does not contain oxygen, fluorine or chlorine; any organic liquid that contains oxygen, fluorine or chlorine if those elements are chemically bonded only to carbon or hydrogen; and any inorganic liquid that does not contain oxygen or halogens.
14	Oxidizing Solids	The following solids need not be classified in any category of this hazard class: any organic solid that does not contain oxygen, fluorine or chlorine; any organic solid that contains oxygen, fluorine or chlorine if those elements are chemically bonded only to carbon or hydrogen; and any inorganic solid that does not contain oxygen or halogens.
15	Organic Peroxides	An organic peroxide that contains any of the following need not be classified in any category of this hazard class: not more than 1.0% available oxygen from the organic peroxides when containing not more than 1.0% hydrogen peroxide; or not more than 0.5% available oxygen from the organic peroxides when containing more than 1.0% but not more than 7.0% hydrogen peroxide.
21	Chemicals Under Pressure	Any product that is classified in a category of the hazard class "Aerosols" must not be classified in any category of this hazard class.

The exclusions either use the language "need not be classified in any category of this hazard class" or "must not be classified in any category of this hazard class". The language of "need not" indicates that it is not necessary to classify a product in a category of the hazard class that the exclusion is for if the conditions of the exclusion are met. However, you may classify in the hazard class if the product meets the classification criteria. The language of "must not" indicates that a product cannot be classified in a category of the hazard class that the exclusion is for if the conditions of the exclusion are met.

For more information on the "exclusion(s)" provisions, please refer to the individual discussions of each Subpart.

Acronyms referred to in Part 7 – Physical Hazards

CLP

Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures

ECHA

European Chemicals Agency

GHS

Globally Harmonized System of Classification and Labelling of Chemicals, seventh revised edition, 2017

HPA

Hazardous Product Act

HPR

Hazardous Product Regulations

UN

United Nations

Subpart 1 Explosives

Subpart 2 Flammable Gases

Discussion – Flammable Gas

The flammable range is determined by tests or by use of a calculation method. However, in accordance with subsection 7.2.1(3) of the HPR, test data have priority over data obtained using a calculation method.

Discussion – Pyrophoric Gas

The term "pyrophoric" applies to the ability of a substance or mixture to spontaneously ignite in air, without a supplied spark, flame, heat or other ignition source. The reaction is exothermic and almost instantaneous (within minutes).

It is important to note that spontaneous ignition for pyrophoric gases is not always immediate, and there may be a delay (GHS seventh revised edition, 2017, paragraph 2.2.2.1, note 4). Spontaneous means that an event occurs without apparent external energy and in the context of this hazard the dispersion of the gas in air is enough to cause the reaction. Spontaneity is not associated with a time factor.

Classification in a Category or Subcategory of the Class

Discussion of subsection 7.2.1(1) of the Hazardous Products Regulations

The criteria for classification in the Aerosols hazard class are found in section 7.3.1 of the HPR.

Discussion of subsection 7.2.1(1.1) of the Hazardous Products Regulations

If a product is classified in the Chemicals Under Pressure hazard class, it must not be classified in the Flammable Gases hazard class. The criteria for classification in the Chemicals Under Pressure hazard class are found in section 7.21.1 of the HPR.

Discussion of subsection 7.2.1(2) of the Hazardous Products Regulations

To ignite a flammable gas, 3 basic conditions have to be met:

• the concentration of the gas must be within the concentration range over which the gas can be ignited, that is, between the lower and upper flammable limits of the gas;
• an oxidizing gas (for example, air) must be present; and
• there must be a source of

The lower flammable limit (LFL) is the minimum concentration (per cent by volume) of a gas in air below which a flame is not propagated when an ignition source is present; (that is, at any lower concentration the gas is "too lean" to burn). Similarly, the upper flammable limit (UFL) is the maximum concentration above which the gas is "too rich" to burn. (Fire Protection Guide to Hazardous Materials, 13^th Edition, 2002, National Fire Protection Association (NFPA) 325 p. 5)

The flammable range is the range between LFL and UFL. It is measured in percentage points between the UFL and LFL. For example, if a gas is ignitable at a LFL of 20% and a UFL of 30%, then it has a flammable range of 10 percentage points (30-20=10).

To classify a flammable gas under the HPR, test results on its flammability must have been conducted in standard conditions (at 20°C and at the pressure of 101.3 kPa). The necessary data to classify a flammable gas in a flammable gas category or subcategory of the class includes the flammable range and information on whether the gas is ignitable at a concentration of 13% gas in air by volume, or less. The lower flammability limit or fundamental burning velocity is necessary for classification of a flammable gas in Flammable Gases — Category 1B, Flammable Gas.

A gas that does not have a flammable range under standard conditions must not be classified in the Flammable Gases hazard class.

A gas which has a flammable range under standard conditions must be classified in Flammable Gases — Category 1A, Flammable Gas if at least 1 of the 2 criteria is met:

1. the gas ignites at a concentration of 13% in air by volume, or less, or
2. its flammable range when mixed with air in any proportion is higher than or equal to 12 percentage points (for example, it could have a flammable range from 60% - 80% or from 14% - 26%)

unless it meets the criteria for the subcategory Flammable Gases — Category 1B, Flammable Gas. In the absence of data permitting classification into the subcategory Flammable Gases — Category 1B, Flammable Gas, a flammable gas that meets the criteria for Flammable Gases — Category 1A, Flammable Gas is classified into the subcategory Flammable Gases — Category 1A, Flammable Gas.

A gas which has a flammable range under standard conditions must be classified in Flammable Gases — Category 1B if it meets the criteria for "Flammable Gases — Category 1A, Flammable Gas" but is not a chemically unstable gas or pyrophoric gas, if at least 1 of the 2 criteria is met:

1. a lower flammability limit of > 6% by volume in air; or
2. a fundamental burning velocity < 10 cm/s.

Otherwise, a gas which has a flammable range under standard conditions must be classified in Flammable Gases — Category 2.

Test Methods

The HPR does not include a specific test method for classifying a gas in a flammable gas category or subcategory. The following test methods are appropriate, although other scientifically validated methods may also be used:

• ISO 10156:2017 "Gases and gas mixtures – Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets" to determine flammability and flammability limits
• ISO 817:2014 "Refrigerants Designation and safety classification, Annex C: Method of test for burning velocity measurement of flammable gases" to determine fundamental burning velocity (GHS, seventh revised edition, 2017, paragraph 2.4.2.1).

Discussion of subsection 7.2.1(2.1) of the Hazardous Products Regulations

Test Methods

The HPR does not include a specific test method for classifying a gas in a chemically unstable gas subcategory. The following test method is appropriate, although other scientifically validated methods may also be used:

• Part III of the Manual of Tests and Criteria

If calculations in accordance with ISO 10156:2017 show that a gas mixture is not flammable, it is not necessary to carry out the tests for determining chemical instability for classification purposes (GHS, seventh revised edition, 2017, paragraph 2.2.4.2.4).

Discussion of subsection 7.2.1(2.2) of the Hazardous Products Regulations

A gas is not classified in the pyrophoric gas subcategory when experience in production or handling shows that the gas does not ignite spontaneously when it comes into contact with air at a temperature of 54°C or below. Flammable gas mixtures that contain more than 1% pyrophoric components should be classified in the pyrophoric gas subcategory unless available data supports non-classification (GHS, seventh revised edition, 2017, paragraph 2.2.2.1, note 5).

Test Methods

The HPR does not include a specific test method for classifying a gas in the pyrophoric gas subcategory. The following test methods are appropriate, although other scientifically validated methods may also be used:

• IEC 60079-20-1 ed 1.0 (2010-01): Explosive Atmospheres – Part 20-1: Material characteristics for gas and vapour classification - Test methods and data
• DIN 51794: Determining the ignition temperature of petroleum products. (GHS, seventh revised edition, 2017, paragraph 2.4.2.2)

Discussion of subsection 7.2.1(3) of the Hazardous Products Regulations

Test data have priority over data obtained using a calculation method. If test results are not available, or if the available data is insufficient for classification, calculation methods can be used as an alternative.

The calculation method must be either the method set out in ISO 10156:2017, as amended from time to time, or another scientifically validated calculation method.

An example of a calculation and the criteria are detailed in Example 2 of the classification of Flammable Gases examples.

Discussion of subsection 7.2.1(4) of the Hazardous Products Regulations

If a scientifically valid calculation method is used, the results of the calculation may allow for the gas to be classified in a category or subcategory of this hazard class. The gas must be classified in accordance with the tables following subsections 7.2.1(2), 7.2.1(2.1) and 7.2.1(2.2) of the HPR, if the data obtained from the calculation support the classification of the gas in a category or subcategory of this hazard class.

Discussion of subsection 7.2.1(5) of the Hazardous Products Regulations

The calculation method described in ISO 10156:2017 determines only if the mixture is flammable or not. It does not determine a flammability range (ECHA Guidance, 2017, paragraph 2.2.4.4). Therefore, this calculation method cannot be used to determine if the mixture meets the criteria of Category 1A, Flammable Gas of the Flammable Gases hazard class. Furthermore, additional information is required to determine if the mixture falls into Category 1B, Flammable Gas, Category 2, Flammable Gas, Category 1A, Chemically Unstable Gas A, Category 1A, Chemically Unstable Gas B or Category 1A, Pyrophoric Gas of the Flammable Gases hazard class. Mixtures determined to be flammable according to the calculation method must be classified as Flammable Gases — Category 1A, Flammable Gas if no additional information is available.

Other scientifically valid calculation methods may be used and may or may not allow a gas to be classified in a category or subcategory depending on the results of the calculation. If the calculation method identifies the gas as being flammable but does not provide enough information to determine in which category or subcategory it falls into, the gas must be classified as Flammable Gases — Category 1A, Flammable Gas.

Hazard Communication

The symbols, signal words, hazard statements, and precautionary statements for "Flammable Gases" are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, p. 307 (Category 1A, Flammable Gas; Category 1B, Flammable Gas; Category 2, Flammable Gas), p. 308 (Category 1A, Pyrophoric Gas) and p. 309 (Category 1A, Chemically Unstable Gas A; Category 1A, Chemically Unstable Gas B). Note: there is no symbol for Category 2.

Classification of Flammable Gases Examples

Example 7.2.1: Classification of a Substance with Known Data

Available data

A gaseous substance with a boiling point of -42°C and a flammable range between 2.2 – 11 % in air at standard conditions (20 °C and 101.3 kPa).

Classification

The gaseous substance meets the criteria for Flammable Gas — Category 1.

Rationale

1. At 20 °C and 101.3 kPa, the substance ignites when mixed with air at a concentration of less than or equal to 13%, criteria (a) of Category 1 is met.

Example 7.2.2: Classification of a Mixture Based on Calculation Method (GHS, seventh revised edition, 2017, paragraph 2.2.5)

Formula for the classification of a flammable gas mixture by calculation according to ISO 10156:2017

The formula for the determination:

Figure 14 - Text description

A formula showing the calculation to determine whether a mixture meets the classification criteria for flammable gas. The formula reads as follows: sum of i through n of V sub i over Tci.

for the determination with:

Figure 15 - Text description

The formula reads as follows: V sub i equals A sub i over the sum of i through n of A sub i plus the sum of 1 through p of K sub k multiplied by B sub k.

where:

Vi (%) = the equivalent content of the ith flammable gas in the mixture, in %;

Tci = the maximum concentration of a flammable gas in nitrogen at which the gas is still not flammable in air, in %;

i = the first gas in the mixture;

n = the number of flammable gases in the mixture; k = the number of inert gases in the mixture;

Ai = is the molar fraction of the ith flammable gas in the mixture, in %;

Kk = is the coefficient of equivalency of the inert gas k relative to nitrogen; Bk = is the molar fraction of the kth inert gas in the mixture, in %;

p = is the number of inert gases in the mixture

The criteria for a gas to be flammable is

Figure 16 - Text description

A formula showing that for a gas to be flammable, the classification formula must exceed a value of 1. The formula reads as follows: Sum of 1 through n of V sub i over Tci all greater than 1.

When a gas mixture contains an inert diluent other than nitrogen, the volume of this diluent is adjusted to the equivalent volume of nitrogen using Kk.

The calculation method applies to gas mixtures and can be applied when the Tci for all flammable components and the Kk for all inert components are available. These values are listed for a number for gases in ISO 10156:2017. In the absence of Tci value for a flammable gas, the value of the Lower Flammable Limit (LFL) can be used, and ISO 10156:2017 proposes the value of 1.5 where no Kk value is listed.

It should be noted that ISO 10156:2017 uses molar fractions in some of its equations. For most gases under normal (that is, non-extreme) conditions, the volume fraction can be assumed to be equal to the molar fraction, which is the same as assuming ideal gas behavior for all gases in the mixture.

For mixtures containing both flammable and oxidizing components, special calculation methods are described in ISO 10156:2017.

Mixture Composition

2% hydrogen (H2) + 6% methane (CH4) + 27% argon (Ar) + 65% helium (He)

Assumptions

1. the equivalency factor (Kk) is 0.55 for the inert gas argon and9 for the inert gas helium;
2. the Tci coefficient is 5.5% for hydrogen and is 8.7% for

Calculations

The equivalent mixture using nitrogen as the balance gas for argon and helium is:

2% (H2) + 6% (CH4) + [27% x 0.55 + 65% x 0.9](N2) = 2% (H2) + 6% (CH4) + 73.35% (N2) = 81.35%

The adjusted sum of the contents to 100% is:

Figure 17 - Text description

The formula reads as follows: 100 over 81.35 multiplied by in brackets 2 percent of H sub 2 plus 6 percent of CH sub 4 plus 73.35 percent of N sub 2 close brackets is equal to 2.46 percent of H sub2 plus 7.37 percent of CH sub 4 plus 90.17 percent of N sub 2.

the flammability of the equivalent mixture is:

Figure 18 - Text description

The formula reads as follows: sum of i through n of V sub I over Tci equals to 2.46 over 5.5 plus 7.37 over 8.7 equals to 1.29.

Therefore, the mixture is flammable in air.

Classification

The gas mixture meets the criteria for classification as a Flammable Gas — Category 1.

Rationale

1. The result of the calculation is 1.29 which is >1, therefore the volume of ignitable gas (Vi) is higher than the minimum volume of gas (Tci) which will ignite in
2. The result of the calculation does not allow for a determination of the classification category based on the criteria, therefore by default it is classified in Category

Example 7.2.3: Classification of Flammable Gases — Category 1A, Pyrophoric Gas

Some examples of pyrophoric gases are: diborane, phosphine and silane (OSHA Hazard Classification Guidance 2016, p. 322).

Subpart 3 Aerosols

The definition of "aerosol dispenser" is found in subsection 1(1) of the HPR and is discussed in subsection 1(1) of this guidance.

Discussion – Aerosol

The GHS defines aerosols as aerosol dispensers, which refers to "any non-refillable receptacles made of metal, glass or plastics and containing a gas compressed, liquefied or dissolved under pressure, with or without a liquid, paste or powder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder or in a liquid state or in a gaseous state" (GHS, seventh revised edition, 2017, paragraph 2.3.1).

However, the definitions used in the HPR distinguish between the dispensed contents and the container. The dispensed contents are defined as a "foam aerosol" or "spray aerosol". The container is referred to as an "aerosol dispenser". "Aerosol dispenser" is defined in subsection 1(1) of the HPR.

Aerosols are classified in 1 of the 3 categories of this hazard class based on the flammable components, the heat of combustion and, if applicable, on the results of the foam test (for foam aerosols), ignition distance test and enclosed space test (for spray aerosols).

As per subsection 7.3.1 of the HPR, the classification of Aerosols is based on tests described in Part III of the Manual of Tests and Criteria, as amended from time to time, where details on the Ignition Distance Test, Enclosed Space Ignition Test, and Aerosol Foam Flammability Test are provided in sub-sections 31.4, 31.5 and 31.6, respectively.

Discussion – Flammable Components

The flammable component could be a substance or mixture that is classified in a category or subcategory of the following hazard classes:

• Flammable Gases (Subpart 2 of Part 7 of the HPR)
• Flammable Liquids (Subpart 6 of Part 7 of the HPR or
• Flammable Solids (Subpart 7 of Part 7 of the HPR)

Aerosols should be considered for classification in Category 1 or 2 of the Aerosols hazard class if they contain more than 1% components (by mass) which are classified as flammable.

Notes:

1. Flammable components do not include substances and mixtures which are pyrophoric, self-heating or water reactive because such components are never used as aerosol contents.
2. Aerosols need not be classified in the Flammable Gases, Flammable Liquids, or Flammable Solids hazard See subsections 7.2.1(1), 7.6.1(1) and 7.7.1(1) of the HPR.

Discussion – Foam Aerosol and Spray Aerosol

The terms "foam aerosol" and "spray aerosol" are not defined in the GHS. However, if testing is being conducted on the aerosol, certain aerosols should be subjected to the foam aerosol test and others to the spray aerosol test. Spray aerosols and foam aerosols can be distinguished by the distance that the aerosol contents travel when ejected. Therefore, these definitions are included in section 7.3 of the HPR (spray aerosol and foam aerosol) to specify what they mean in the classification criteria.

Classification in a Category of the Class

Discussion of subsection 7.3.1(1) of the Hazardous Products Regulations

If a product is classified in the Chemicals Under Pressure hazard class, it must not be classified in the Aerosols hazard class. The criteria for classification in the Chemicals Under Pressure hazard class are found in section 7.21.1 of the HPR.

Discussion of subsection 7.3.1(2) of the Hazardous Products Regulations

An aerosol is classified in either Category 1, Category 2 or Category 3 of the Aerosols hazard class on the basis of:

• its flammable components and its heat of combustion or,
• if applicable, the results of the foam test (for foam aerosols), the ignition distance test or enclosed space ignition test (for spray aerosols), in the test procedure specified in subsection 7.3.1(2) of the

The ignition distance test is the method used to determine the distance from the aerosol dispenser at which the aerosol spray can be ignited. This test is applicable to aerosol products that can spray a distance of 15 cm or more. Ignition at greater distances increases the possibility of contact of the spray with an ignition source during use.

Aerosol products with a spray distance of less than 15 cm, such as dispensing foams, mousses, gels and pastes or that are fitted with a metering valve, are excluded from this test. Aerosol products that dispense foams, mousses, gels or pastes are subject to testing under the aerosol foam flammability test. The aerosol foam flammability test is the method to determine the flammability of an aerosol emitted in the form of a foam, mousse, gel or paste.

The enclosed space ignition test is the method used to assess the flammability of products emerging from aerosol dispensers based on their propensity to ignite in an enclosed or confined space.

The specific heats of combustion may be found in literature, calculated or determined by testing. For a composite formulation, the specific heat of combustion of the product is the summation of the weighted heats of combustion for the individual components, as follows:

Figure 19 - Text description

A formula that describes the components that contribute to the heats of combustion of the product. The formula reads as follows: Delta of H sub c equals the sum of in brackets w of i multiplied by delta of H sub c of i close brackets.

where:

DHc (product) = specific heat of combustion (kJ/g)

DHc (i) = specific heat of combustion (kJ/g) of component i in the product

w(i) = mass fraction of component i in the product

n = total number of components in the product

(GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

The heats of combustion can be determined by the following tests methods or other scientifically validated methods:

• ASTM D240-19: Standard Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter;
• ISO 13943: 2017: Fire Safety - Vocabulary, Third Edition, July 2017, Sections 86.1 to 86.3; and
• NFPA 30B, Code for the Manufacture and Storage of Aerosol Products, 2023 Edition.
• (GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

When a product is not tested and it contains flammable components (liquids, gases or solids) in an aerosol dispenser, the product must be classified in Aerosols — Category 1. The only exception is when the aerosol dispenser contains the flammable components at a concentration ≤ 1.0% and has a heat of combustion of < 20 kJ/g. In that case, the product must be classified in Category 3 of this hazard class in accordance with the table to subsection 7.3.1(2) of the HPR.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Aerosols are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017, p. 310 (Category 1 and Category 2) and p. 311 (Category 3).

Classification of Aerosols Examples

(GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

Example 7.3.1:

The following example explains the classification process for a product suspected of being a flammable aerosol when data on flammable components and on the heat of combustion are known.

Available data

The product FA1 is an aerosol with:

• Flammable components: 70% (by mass) butane/propane, 25% (by mass) ethanol
• Non-flammable components: 5%
• The specific heats of combustion (ΔH_c) for gases in the mixture:
  • ΔH_c (butane/propane) = 43.5 kJ/g
  • ΔH_c (ethanol) = 24.7 kJ/g
  • ΔH_c (other non-flammable components) = 0 kJ/g

Classification

The product FA1 meets the criteria for Aerosols — Category 1.

Rationale

The specific heat of combustion (ΔH_c) of the product can be calculated using the formula presented below:

• ΔH_c (product) = å[ w(i) x DHc(i)]
• ΔH_c (FA1) = [w(i) x ΔH_c(i) for butane/propane] + [w(i) x ΔH_c(i) for ethanol] + [w(i) x ΔH_c(i) for the non-flammable components]
• ΔH_c (FA1) = [0.70 x 43.5] + [0.25 x 24.7] + [0.5 x 0] = 30.45 + 6.175 + 0 = 36.6

The information gathered is then compared to the classification criteria:

1. Does FA1 contain ≤1% flammable components and does it have a heat of combustion

< 20 kJ/g?

No. It has 95% flammable components and the heat of combustion is 36.6 kJ/g. Therefore it is subject to classification in this hazard class.

2. Does FA1 contain ≥ 85% flammable components and does it have a heat of combustion

≥ 30 kJ/g?

Yes. It has 95% flammable components and the heat of combustion is 36.6 kJ/g.

Therefore, product FA1 is classified in Aerosols — Category 1.

Example 7.3.2:

In this example, data on flammable components, the heats of combustion and the results of the ignition distance test (for spray aerosols) are known.

Available data

The product FA2 is a spray aerosol with:

• Flammable components: 30% (by mass) butane/propane
• Non-flammable components: 70% (by mass)
• The specific heats of combustion (ΔH_c) for gases in the mixture:
  • ΔH_c (butane/propane) = 43.5 kJ/g
  • ΔH_c (other non-flammable components) = 0 kJ/g
• Results of the ignition distance test: ignition occurs at less than 75 cm but more than 15 cm.
• Results of enclosed space ignition test: not conducted

Classification

The product FA2 meets the criteria for Aerosols — Category 2.

Rationale

The specific heat of combustion (ΔH_c) of the product can be calculated using the formula presented below

ΔH_c (product) = å[ w(i) x DHc(i)]

ΔH_c (FA2) = [w(i) x ΔH_c(i) for butane/propane] + [w(i) x ΔH_c(i) for the non-flammable components]

ΔH_c (FA2) = [0.30 x 43.5] + [0.7 x 0] = 13.05 + 0 = 13.1 kJ/g

The information gathered is then compared to the classification criteria:

1. Does FA2 contain ≤ 1% flammable components and does it have a heat of combustion

   < 20 kJ/g?

   No. it has 30% flammable components and the heat of combustion is 13.1 kJ/g. Therefore it is subject to classification in this hazard class.

2. Does FA2 contain ≥ 85% flammable components and does it have a heat of combustion

   ≥ 30 kJ/g?

   No. FA2 has 30% flammable components and the heat of combustion is 13.1 kJ/g.

3. In the ignition distance test, does ignition occur at a distance ≥ 75 cm?

   No. Ignition occurred at less than 75 cm and more than 15 cm.

4. Does FA2 have a heat of combustion < 20 kJ/g?

   Yes. The heat of combustion is 13.1 kJ/g.

5. In the ignition distance test, does ignition occur at a distance ≥ 15 cm?

   Yes. The ignition occurs at less than 75 cm but more than 15 cm.

Therefore, product FA1 is classified in Aerosols — Category 2.

Example 7.3.3:

In this example, data on flammable components, the heats of combustion and the results of the foam test (for foam aerosols) are known:

Available data

Product FA3 is a foaming aerosol with:

• Flammable components: 4% (by mass) butane/propane
• Non-flammable components: 96%
• The specific heats of combustion (ΔH_c) for gases in the mixture:

o ΔH_c (butane/propane) = 43.5 kJ/g

• ΔH_c (other non-flammable components) = 0 kJ/g
• Results of the foam test: the flame height is less than 4 cm and the flame duration is less than 2 seconds

Classification

The product FA3 does not meet any of the criteria for Aerosols.

Rationale

The specific heat of combustion (ΔH_c) of the product can be calculated using the formula presented below:

ΔH_c (product) = å[ w(i) x DHc(i)]

ΔH_c (FA3) = [w(i) x ΔH_c(i) for butane/propane] + [w(i) x ΔH_c(i) for the non-flammable components]

ΔH_c (FA3) = [0.04 x 43.5] + [0.96 x 0] = 1.74 + 0 = 1.7 kJ/g

The information gathered is then compared to the classification criteria:

1. Does FA3 contain ≤ 1% flammable components and does it have a heat of combustion

< 20 kJ/g?

No. FA3 has 4% flammable components and the heat of combustion is 1.7 kJ/g.

2. Does FA3 contain ≥ 85% flammable components and does it have a heat of combustion

≥ 30 kJ/g?

No. FA3 has 4% flammable components and the heat of combustion is 1.7 kJ/g

3. In the foam test, is
   1. the flame height ≥ 20 cm and the flame duration ≥ 2 seconds; or
   2. is the flame height ≥ 4 cm and the flame duration ≥ 7 seconds?

No. In the foam test, the flame height is less than 4 cm and the flame duration less than 2 seconds.

4. In the foam test, is the flame height ≥ 4 cm and the flame duration ≥ 2 seconds?

No. In the foam test, the flame height is less than 4 cm and the flame duration less than 2 seconds.

Therefore, product FA3 is not classified in the Aerosols hazard class.

Subpart 4 Oxidizing Gases

Discussion – Oxidizing Gas and Oxidizer

In general terms, an oxidizer is a chemical that brings about an oxidation reaction. An oxidizing reaction means:

• the oxidizer provides oxygen to the substance being oxidized (in which case the oxidizer has to be oxygen or contain oxygen), or
• the oxidizer receives electrons from the substance being oxidized (for example, chlorine is a good oxidizer for electron-transfer purposes, even though it contains no oxygen).

Oxidizers can initiate or greatly accelerate the combustion of other materials. The most common oxidizer is atmospheric oxygen. "A gas that is liable to cause or contribute to the combustion of other materials more than air does" means that the gas or gas mixture has an oxidizing power of greater than 23.5%. This value is associated with the quantity of oxygen in air. Oxygen makes up approximately 21% by volume of the composition of air. When a gas has an oxidizing power of greater than 23.5% it exceeds the contribution of air alone and is then considered an oxidizing gas.

Classification in a Category of the Class

Discussion of section 7.4.1 of the Hazardous Products Regulations

To classify an oxidizing gas, data from tests or calculation methods as described in ISO 10156:2017 Gases and gas mixtures – Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets, as amended from time to time, must be used.

ISO 10156:2017 specifies methods for determining whether or not a gas or gas mixture is flammable in air, and whether a gas or gas mixture is more or less oxidizing than air under atmospheric conditions. The methods are intended to be used for the classification of pure gaseous substances and gas mixtures.

Hazard Communication

The symbol, signal word, as well as hazard and precautionary statements for "Oxidizing Gases" are specified in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, p. 312).

Classification of Oxidizing Gas Example

Example 7.4.1: Classification of an Oxidizing Gas Mixture by Calculation According to ISO 10156:2017 (GHS, seventh revised edition, 2017, paragraph 2.4.4.2)

The method described in ISO 10156:2017 uses the criterion that a gas mixture should be considered as more oxidizing than air if the oxidizing power of the gas mixture is higher than 0.235 (23.5%).

Formula for Calculating Oxidizing Power

The oxidizing power (OP) is calculated as follows:

Figure 20 - Text description

The formula reads as follows: OP equals sum of I equals 1 through n of X sub I multiplied by C sub I all over the sum of I equals 1 through n of X sub I plus the sum of K equals 1 through p of K sub k multiplied by B sub k.

Where:

• Xi = molar fraction of the ith oxidizing gas in the mixture;
• Ci = coefficient of oxygen equivalency of the ith oxidizing gas in the mixture;
• Kk = coefficient of equivalency of the inert gas k compared to nitrogen;
• Bk = molar fraction of the kth inert gas in the mixture;
• n = total number of oxidizing gases in the mixture and i is running from 1 to n; p = total number of inert gases in the mixture and k is running from 1 to p;

Example mixture: 9% (O2) + 16% (N2O) + 75% (He)

Available data

If the coefficient of oxygen equivalency (Ci) for the oxidizing gases in the mixture and the nitrogen equivalency factors (Kk) for the non-flammable, non-oxidizing gases are known, the oxidizing power can be calculated. In this example, the values are:

• Ci (N2O) = 0.6 (nitrous oxide) Ci (O2) = 1 (oxygen)
• Kk (He) = 0.9 (helium)

The information gathered is then used to complete the calculation:

Figure 21 - Text description

The formula reads as follows: OP equals 0.09 multiplied by 1 plus 0.16 multiplied by 0.6 all over 0.09 plus 0.16 plus 0.75 multiplied by 0.9 equals to 0.201.

OP = 0.201 = 20.1%. The oxidizing power of the gas mixture is 20.1%.

Classification

The mixture does not meet the criteria for classification in Oxidizing Gas — Category 1.

Rationale

1. The calculated oxidizing power of the gas mixture is 20.1%, which is less than the value of >23.5% required for classification.

Subpart 5 Gases Under Pressure

Discussion – Gas Under Pressure

Subsection 1(1) of the HPR provides the definition for "gas" which means a mixture or substance that

1. (a) at 50 °C has an absolute vapour pressure of greater than 300 kPa; or
2. (b) is completely gaseous at 20 °C and at the standard pressure of 101.3

Because the definition of "gas under pressure" refers to a "gas", it excludes any substance or mixture that does not meet the definition of "gas" in the HPR.

Classification in a Category of the Class

Discussion of subsection 7.5.1(1) of the Hazardous Products Regulations

If a product is classified in the Aerosols hazard class, it need not be classified in the Gases Under Pressure hazard class. The criteria for classification in the Aerosols hazard class is found in section 7.3.1 of the HPR.

Discussion of subsection 7.5.1(2) of the Hazardous Products Regulations

If a product is classified in the Chemicals Under Pressure hazard class, it must not be classified in the Gases Under Pressure hazard class. The criteria for classification in the Chemicals Under Pressure hazard class is found in section 7.21.1 of the HPR.

Discussion of subsection 7.5.1(3) of the Hazardous Products Regulations

To classify gases under pressure in this hazard class, the following information is required:

• the vapour pressure at 50 °C
• the physical state at 20 °C and at standard pressure (101.3 kPa), and
• the critical temperature (GHS, seventh revised edition, 2017, section 2.5.4.2)

This data can be found in literature, calculated or determined by testing. In addition, most pure gases are classified in the UN Recommendations on the Transport of Dangerous Goods, Model Regulations. (GHS, seventh revised edition, 2017, section 2.5.4.2) No test methods are specified in the criteria for the classification of Gases Under Pressure.

Gases under pressure are classified in 1 of 4 categories, according to their physical form when packaged, as set out in section 7.5.1 of the HPR. The criteria apply to products that are gases, as defined by the HPR. The classification in one of the categories of the Gases Under Pressure hazard class depends on the characteristics of the gas "when packaged under pressure" or "when packaged". Classification in this hazard class also requires knowledge of the physical form of the gas (that is, entirely gaseous, partially liquid due to pressure or low temperature, or dissolved in liquid phase) when packaged. The same gaseous substance or mixture could be classified in a different category (that is, Compressed Gas, Liquefied Gas, Refrigerated Liquefied Gas OR Dissolved Gas) depending on its packaging.

Note: If the gas is not contained in a receptacle at a pressure of 200 kPa or more at 20 °C, or is not liquefied, or is not liquefied and refrigerated, then the gas does not meet the definition of gas under pressure specified in section 7.5 of the HPR and therefore, is not classified in Gases Under Pressure.

Gases under pressure need to be considered for classification in all other hazard classes relevant to gases, such as the physical hazard classes Flammable Gases, Oxidizing Gases and Simple Asphyxiants, where relevant.

Hazard Communication

The symbol, signal word as well as hazard and precautionary statements for "Gases under Pressure" are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017 on p. 313 for Compressed Gas, Liquefied Gas and Dissolved Gas, and p. 314 for Refrigerated Liquefied Gas.

Classification of Gases Under Pressure Examples

Example 7.5.1: A Substance that is Not Classified

Available data

The substance has a vapour pressure of 200 kPa at 50 °C and is not completely gaseous at 20 °C and standard pressure (101.3 kPa).

Classification

The substance does not meet the criterion for classification as a Gas Under Pressure.

Rationale

1. Does the substance meet the definition of a "gas" under the HPR?

No. The vapour pressure of the gas at 50 °C is 200 kPa which is not greater than 300 kPa, and the gas is not completely gaseous at 20 °C and 101.3 kPa.

The gas does not meet the definition of a gas specified in subsection 1(1) of the HPR and therefore is not considered for classification as a gas under pressure.

Example 7.5.2: Compressed Gas

Available data

• The substance is a gas
• The substance is contained in a receptacle at a pressure of >200 kPa at 20 °C.
• The vapour pressure at 50 °C is > 410
• When packaged under pressure, the substance is entirely gaseous at -50 °C; and
• The critical temperature is -240.1 °C.

Classification

The gas meets the criterion for classification as a Gases Under Pressure — Compressed Gas.

Rationale

1. Is the substance a gas?

   The substance is described as a gas. Extra information is provided.

2. Does the gas meet the definition of "gas under pressure"?

   Yes. The gas is contained in a receptacle at a pressure of 200 kPa or more at 20 °C, and has a vapour pressure at 50 °C of 410 kPa.

3. Does the gas meet the criterion for Dissolved Gas?

   No. The gas is not dissolved in a liquid solvent under pressure.

4. Does the gas meet the criterion for Refrigerated Liquefied Gas?

   No. The gas is not partially liquid because of its low temperature given that when packaged under pressure, it is entirely gaseous at -50 °C.

5. Does the gas meet the criterion for Liquefied Gas?

   No. The gas is not partially liquid at temperatures above -50 °C given that when packaged under pressure, it is entirely gaseous at -50 °C.

6. Does the gas meet the criterion for Compressed Gas?

   Yes. The gas when packaged under pressure is entirely in gaseous state at -50 °C and has a critical temperature of -240.1 °C. A Compressed Gas is a gas which when packaged under pressure is entirely gaseous at -50 °C including all gases with a critical temperature ≤ -50 °C.

Example 7.5.3: Liquefied Gas

Available data

• The substance is a gas with a vapour pressure of 290 kPa at 50 °C.
• The substance is completely gaseous at 20 °C and standard
• The gas is not entirely gaseous at -50 °C.
• The critical temperature is 75.3 °C.
• The gas is contained in a receptacle at a pressure of 200 kPa or more at 20 °C.

Classification

The gas meets the criterion to be classified in Gases Under Pressure — Liquefied Gas.

Rationale

1. Does the substance meet the definition for gas?

   Yes. The substance is completely gaseous at 20 °C and 101.3 kPa.

2. Does the gas meet the definition of "gas under pressure"?

   Yes. The gas is contained in a receptacle at a pressure of 200 kPa or more at 20 °C, and has a vapour pressure at 50 °C of 290 kPa.

3. Does the gas meet the criterion for Dissolved Gas?

   No. The gas when packaged under pressure is not dissolved in a liquid solvent under pressure.

4. Does the gas meet the criterion for Refrigerated Liquefied Gas?

   No. The gas when packaged under pressure is not partially liquid because of its low temperature.

5. Does the gas meet the criterion for Compressed Gas?

   No. The gas is not entirely gaseous at -50 °C; and the critical temperature is 75.3 °C which is not ≤ -50 °C.

6. Does the gas meet the criterion for Liquefied Gas?

   Yes. The gas when packed under pressure is not entirely in gaseous state at 50 °C. A liquefied gas is a gas which when packaged under pressure is partially liquid at temperatures above -50 °C.

Subpart 6 Flammable Liquids

Discussion - Appropriate Closed-Cup Method

A "closed-cup method" refers to a method in which a liquid's vapour is enclosed in the space above the liquid being tested, such that the vapour cannot dissipate. (Open-cup techniques, where the vapour can dissipate, tend to yield flash points with values higher than those obtained with closed-cup methods.) The term "appropriate closed-cup methods" used in subsections 7.6.1(3) and (4) of the HPR, currently refers to the following 10 methods which are listed in the GHS, seventh revised edition, 2017, paragraph 2.6.4.2.5:

• The ISO methods:
  • 1516 - Determination of flash/no flash - Closed cup equilibrium method
  • 1523 - Determination of flash point - Closed cup equilibrium method
  • 2719 - Determination of flash point - Pensky-Martens closed cup method
  • 13736 - Determination of flash point - Abel closed-cup method
  • 3679 - Determination of flash point - Rapid equilibrium closed cup method,
  • 3680 - Determination of flash/no flash - Rapid equilibrium closed cup method
• The ASTM methods:
  • D3828-07a - Standard Test Methods for Flash Point by Small Scale Closed Cup Tester
  • D56-05 - Standard Test Method for Flash Point by Tag Closed Cup Tester
  • D3278-96(2004)e1 - Standard Test Methods for Flash Point of Liquids by Small Scale Closed Cup Apparatus
  • ASTM D93-08 - Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester

Classification in a Category of the Class

Discussion of subsection 7.6.1(1) of the Hazardous Products Regulations

If a product is classified in the Aerosols hazard class, it need not be classified in the Flammable Liquids hazard class. The criteria for classification in the Aerosols hazard class is found in section 7.3.1 of the HPR.

Discussion of subsection 7.6.1(1.1) of the Hazardous Products Regulations

If a product is classified in the Chemicals Under Pressure hazard class, it must not be classified in the Flammable Liquids hazard class. The criteria for classification in the Chemicals Under Pressure hazard class is found in section 7.21.1 of the HPR.

Discussion of subsection 7.6.1(2) of the Hazardous Products Regulations

Subsection 7.6.1(2) of the HPR provides the numeric cut-off criteria for classifying a substance or mixture in 1 of the 4 categories of the Flammable Liquids hazard class.

To classify a substance or mixture in the Flammable Liquids hazard class, data, as determined using standardized methods, are needed on:

• flash point and initial boiling point, for classification in Category 1 and Category 2, and
• flash point, for classification in Category 3 and Category 4

Discussion of subsection 7.6.1(3) of the Hazardous Products Regulations

Subsection 7.6.1(3) of the HPR indicates the relevant information that is appropriate for the determination of the flash point for a substance.

The 10 appropriate closed-cup methods for the determination of the flash point are detailed under the definition "appropriate closed-cup method" in section 7.6. Flash point data reported in the scientific literature and that were obtained by any of the 10 "appropriate closed-cup methods" can also be used in place of experimental determination.

Discussion of subsection 7.6.1(4) of the Hazardous Products Regulations

Subsection 7.6.1(4) of the HPR indicates the relevant information that is appropriate for the determination of the flash point for a mixture.

The titles of 10 appropriate closed-cup methods for the determination of the flash point are provided under the definition "appropriate closed-cup method" in section 7.6. Also, a calculation method may be used only if the method has been validated for the type of mixture that is being assessed. There is only 1 validated calculation method currently available for determining the flash point of a mixture. The GHS seventh revised edition, 2017, paragraphs 2.6.4.2.2 and 2.6.4.2.3 outline the requirements and restrictions of this method.

Hazard Communication

The symbols, signal words as well as hazard and precautionary statements for Flammable Liquids Categories 1 to 4 are provided in Section 3 of Annex 3 of the GHS seventh revised edition, 2017 on pages 315-316.

Classification of Flammable Liquids Examples

Example 7.6.1:

Available data

• Diethyl ether (CAS# 60-29-7): Flash point (closed cup) = -40 °C; initial boiling point = 34.5 °C

Classification

• Meets criteria for classification in Flammable Liquids — Category 1

Rationale

• Flash point is <23°C and the initial boiling point ≤35°C

Example 7.6.2:

Available data

• Pentane (CAS# 109-66-0): Flash point (closed cup) < -40 °C; initial boiling point = 36 °C

Classification

• Meets criteria for classification in Flammable Liquids — Category 2

Rationale

• Flash point is <23°C and the initial boiling point >35°C

Example 7.6.3:

Available data

• Cyclohexanone (CAS# 108-94-1): Flash point (closed cup) = 47°C

Classification

• Meets criteria for classification in Flammable Liquids — Category 3

Rationale

• Flash point is ≥23°C and ≤60°C

Example 7.6.4:

Available data

• 2-Mercaptoethanol (CAS# 60-24-2): Flash point (closed cup) = 67°C

Classification

• Meets criteria for classification in Flammable Liquids — Category 4

Rationale

• Flash point is >60°C and ≤93°C

Subpart 7 Flammable Solids

Discussion

A solid can have many physical forms (for example, dusts, particulates, granules, ingots, massive solids) that can differ in the surface area available for chemical reactions. The finer the particle size of a solid, the greater the surface area exposed to air. Since flammability is a reaction with the oxygen in the air, the particle size will greatly influence the ability of a solid to ignite.

Many organic solids meet the criteria to be classified in the Flammable Solids hazard class; however, it is rare for inorganic solids to be classified in the Flammable Solids hazard class. The exception is powders of metals or metal alloys. Metal powders are especially dangerous because normal extinguishing agents such as carbon dioxide or water can increase the hazard when used to extinguish a fire (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraph 2.4.2.2.1.2). The classification criteria outlined in the HPR for Flammable Solids assess metal powders separately from other solids.

Classification in a Category of the Class

Discussion of subsection 7.7.1(1) of the Hazardous Products Regulations

If a product is classified in the Aerosols hazard class, it need not also be classified in the Flammable Solids hazard class. The criteria for classification in the Aerosols hazard class is found in section 7.3.1 of the HPR.

Discussion of subsection 7.7.1(1.1) of the Hazardous Products Regulations

If a product is classified in the Chemicals Under Pressure hazard class, it must not be classified in the Flammable Solids hazard class. The criteria for classification in the Chemicals Under Pressure hazard class is found in section 7.21.1 of the HPR.

Discussion of subsection 7.7.1(2) of the Hazardous Products Regulations

If testing is done, it must be performed using the burning rate test in sub-section 33.2 of Part III of the Manual of Tests and Criteria, as amended from time to time, where a complete description of the method and analysis of the test results are described. The UN method consists of 2 tests: a preliminary screening test and a burning rate test (GHS, seventh revised edition, 2017, section 2.7.4). The screening test is performed to determine if, on ignition by a gas flame, propagation by burning with flame or smouldering occurs. If propagation occurs within a specified time then the full test is carried out to determine the rate and vigour of burning. (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 33.2.3.1)

Classification and categorization for metal powders is determined based on burn time alone. If the reaction spreads over the whole length of the sample in 10 minutes or less, it meets the criteria to be classified in the Flammable Solids hazard class. If the burn time is 5 minutes or less, the metal powder falls into Category 1. If the burn time is more than 5 minutes but not more than 10 minutes, the metal powder is classified in Category 2.

Classification and categorization for all other solids is determined based on burn time as well as the ability or inability of the wetted zone to stop the flame propagation. The burn time must be less than 45 seconds, or the burn rate greater than 2.2 mm/s, to meet the criteria to classify as a Flammable Solid. If the burn time is less than 45 seconds, or the burn rate greater than 2.2 mm/s and the wetted zone is unable to stop the fire or stops the fire for less than 4 minutes, the solid falls into Category 1. If the burn time is less than 45 seconds, or the burn rate is greater than 2.2 mm/s, and the wetted zone stops the fire for 4 minutes or longer, the solid is classified in Category 2.

Discussion of subsection 7.7.1(3) of the Hazardous Products Regulations

Subsection 7.7.1(3) of the HPR specifies that any flammable solid that is liable to cause or contribute to fire through friction must be classified in Category 2.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Flammable Solids Category 1 and Category 2 are specified in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017 on p. 317.

Classification of Flammable Solids Example

Example 7.7.1:

(CLP Guidance, 2015, paragraph 2.7.7.1)

Available data

• Substance X is not a metal powder
• Based on the screening test, Substance X will burn or smoulder when in contact with a flame and is a candidate for classification as a flammable solid and further consideration is required
• According to test N.1 of sub-section 33.2.4 of Part III of the Manual of Tests and Criteria, 6 runs were performed and the resulting burning times for a distance of 100 mm were obtained (in seconds): 44, 40, 49, 45, 37, 41. The wetted zone stopped the fire without reignition

Classification

• Substance X meets the criteria to be classified in the Flammable Solids — Category 2 hazard class

Rationale

• The shortest burning time is less than 45 seconds, therefore Substance X meets 1 of the criteria specified in the Table to subsection 7.7.1(2) of the HPR
• The wetted zone stopped the fire completely (meeting the minimum time of 4 minutes), therefore Substance X is classified in Category 2

Subpart 8 Self-Reactive Substances and Mixtures

Discussion – As Packaged

The methodology of the test series (that is, series B, D, G and H of Part II of the Manual of Tests and Criteria) used to classify self-reactive substances and mixtures requires that the substance or mixture be tested "as packaged" (Manual of Tests and Criteria, seventh revised edition, 2019, sub-sections 22.1, 24.1, 27.1, 28.1).

Discussion - Explosive Properties

The above definition for explosive properties is derived from the following statement from the GHS:

"A self-reactive substance or mixture is regarded as possessing explosive properties when in laboratory testing the formulation is liable to detonate, to deflagrate rapidly or to show a violent effect when heated under confinement." (GHS, seventh revised edition, 2017, paragraph 2.8.1.2)

The test methods are included in the definition given in section 7.8 of the HPR because results from these tests are used to conclude whether a substance or mixture has explosive properties for the purposes of this subpart.

Discussion – Self-Reactive

The statement "having a heat of decomposition equal to or greater than 300 J/g" is included to the HPR definition to more clearly define the phrase "strongly exothermic", used in the same definition.

Self-reactive substances and mixtures vary considerably in their properties and formulations. Certain chemical groups, however, are indicative of self-reactive properties (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraph 2.4.2.3.1.2) and include:

• Aliphatic azo compounds (-C-N=N-C-);
• Organic azides (-C-N3);
• Diazonium salts (-CN₂⁺Z^-);
• N-nitroso compounds (-N-N=O); and
• Aromatic sulfohydrazides (-SO2-NH-NH₂).

Note: The above is not an exhaustive list. Substances with other reactive groups, combinations of groups and some mixtures of substances may have similar properties. Additional information on self-reactive properties is given in the Manual of Tests and Criteria, Appendix 6 – Screening Procedures. (Manual of Tests and Criteria, seventh revised edition, 2019, Appendix 6, sub-section 5.1)

All self-reactive substances and mixtures undergo strong exothermic decomposition that "…can be initiated by heat, contact with catalytic impurities (for example, acids, heavy-metal compounds, and bases), friction, or impact. The rate of decomposition increases with temperature and varies with the substance. Decomposition, particularly if no ignition occurs, may result in the evolution of toxic gases or vapours. For certain self-reactive substances, the temperature shall be controlled. Some self-reactive substances may decompose explosively, particularly if confined. This characteristic may be modified by the addition of diluents or by the use of appropriate packagings. Some self-reactive substances burn vigorously." (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraph 2.4.2.3.1.2) This also applies to self-reactive mixtures.

Other applicable definitions

The following terms are used in this chapter. The definitions of these terms appear under Part 1 Interpretation of the HPR.

The definition of "Manual of Tests and Criteria" specifies that the document is "amended from time to time", this means that the classification must be based on the test series contained in the most recent version of the Manual of Tests and Criteria.

Discussion – SADT

Self-reactive substances or mixtures when held at moderate ambient temperatures for an extended period of time undergo self-heating as a result of slow thermal degradation. This exothermic reaction accelerates with increasing temperature. If the heat does not dissipate into the environment as quickly as it is generated, the resulting increase in temperature will further intensify the rate of decomposition. Unchecked, the temperature can increase exponentially to a point where decomposition cannot be stopped. This reaction creates a dangerous situation known as self-accelerating decomposition.

The self-accelerating decomposition temperature (SADT) is the lowest temperature at which a packaged self-reactive substance or mixture will undergo a self-accelerating decomposition. "The SADT and SAPT are measures of the combined effect of the ambient temperature, reaction kinetics, package size and the heat transfer properties of the substance and its packaging." (Manual of Tests and Criteria, seventh revised edition, 2019, sub-sections 20.4.1.3 and 28.1) The SAPT refers to the self-accelerating polymerization temperature. The SAPT is not a term that is used in the HPR.

4 tests are described in the Manual of Tests and Criteria for determining the SADT:

• United States SADT test
• Adiabatic storage test (AST)
• Isothermal storage test (IST)
• Heat accumulation storage test

A detailed description of the test methods is provided in the Manual of Tests and Criteria. These test methods or any other suitable validated test method may be used to determine the SADT.

Classification in a Category of the Class

Discussion of subsection 7.8.1(1) of the Hazardous Products Regulations

Subsection 7.8.1(1) of the HPR details the exclusion criteria for substances and mixtures that do not need to be classified in the Self-Reactive Substances and Mixtures hazard class. The exclusion criteria are as follows:

• substances and mixtures that are classified as Organic Peroxides under section 7.15 of the HPR
• mixtures that are classified as Oxidizing Liquids or Oxidizing Solids under sections 7.13 and 7.14 of the HPR respectively, if they contain <5.0 % of combustible organic substances and
• substances that are classified as Oxidizing Liquids or Oxidizing Solids under section 7.13 or 7.14 of the HPR respectively.

Discussion of subsection 7.8.1(2) of the Hazardous Products Regulations

Self-reactive substances and mixtures are classified into 7 categories (Types A to G) according to the degree of danger they present as defined by their ability to detonate, to deflagrate, and to react while heated under confinement. Type A is the most severe hazard category while Type G is the least severe.

The criteria for Types A, B, and C specify that the self-reactive substance or mixture be tested "as packaged" since "stronger packaging may result in more violent reactions when the substance or mixture decomposes" (ECHA Guidance, 2017, paragraph 2.8.4.1). The words "in laboratory testing" in Types D, E, F and G criteria imply that the self-reactive substance or mixture is tested in its non-packaged form. Types F and G have conditional criteria that also require testing in a "50 kg package".

Appendix 6 to the Manual of Tests and Criteria provides guidance on screening substances and mixtures before testing. This guidance is based on the potential of certain chemical groups to exhibit explosive or self-reactive properties. These chemical groups include:

Chemical groups indicating explosive properties of organic materials:

• C-C unsaturation (for example, acetylenes, acetylides, 1,2-dienes)
• C-Metal, N-Metal (for example, Grignard reagents, organo-lithium compounds)
• Contiguous nitrogen atoms (for example, azides, aliphatic azo compounds, diazonium salts, hydrazines, sulphonyl hydrazides)
• Contiguous oxygen atoms (for example, peroxides, ozonides)
• N-O (for example, hydroxylamines, nitrates, nitro compounds, nitroso compounds, N-oxides, 1,2-oxazoles)
• N-halogens (for example, chloroamines, fluoroamines)
• O-halogens (for example, chlorates, perchlorates, iodosyl compounds)

Chemical groups indicating self-reactive properties of organic materials:

• Mutually reactive groups (for example, aminonitriles, haloanilines, organic salts of oxidizing acids)
• S=O (for example, sulphonyl halides, sulphonyl cyanides, sulphonyl hydrazides)
• P-O (for example, phosphites)
• Strained rings (for example, epoxides, aziridines)
• Unsaturation (for example, olefins, cyanates)

Desensitization, mentioned in the criteria for Types F and G, refers to the addition of a diluent to a self-reactive substance to increase its stability. The UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraphs 2.4.2.3.5.2, 2.4.2.3.5.3 and 2.4.2.3.5.4 provide specifications for acceptable diluents.

Testing

If testing is done, it must be performed using test series A to H as described in sections 20 to 28 of Part II of the Manual of Tests and Criteria, which are designed to answer the questions given in the flowchart (Figure 20.1 of the Manual of Tests and Criteria - Flowchart Scheme for Self- Reactive Substances and Organic Peroxides) and Decision Logic 2.8 for self-reactive substances and mixtures on p. 80 of the GHS (seventh revised edition, 2017).

The tests are performed in 2 stages. The first stage uses preliminary small-scale testing to determine the sensitivity of the substance or mixture to mechanical stimuli (impact and friction), and to heat and flame (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.3.1). The preliminary testing consists of the following procedures:

1. a falling weight test to determine sensitiveness to impact,
2. a friction or impact test to determine the sensitiveness to friction,
3. a test to assess thermal stability and the exothermic decomposition energy, and
4. a test to assess the effect of

(Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.3.2)

The second stage of testing involves testing for classification purposes. Results from test series A to H are used to answer questions in the GHS Decision Logic 2.8 for self-reactive substances and mixtures (p. 80 of the GHS, seventh revised edition, 2017) relating to:

• Propagation of detonation,
• Propagation of deflagration,
• Effect on heating in confinement, and
• Thermal

The sequence of test series A to H is based more on assessing results than on the order in which tests are actually conducted. The recommended sequence of laboratory scale testing is test series E, H, F, C and then A, although some tests may not be required. The package tests of test series B, D, and G only need to be performed if indicated by the results from the corresponding tests in test series A, C, and E. (Manual of Tests and Criteria, seventh revised edition, 2019, sub-sections 20.4.6.1 and 20.4.6.2)

Note: The test series described in Part II of the Manual of Tests and Criteria are not equivalent to the classification types listed under subsection 7.8.1(2) of the HPR. For example, from the Decision logic 2.8 for self-reactive substances and mixtures in the GHS (p. 80 of the GHS, seventh revised edition, 2017), testing to classify a substance or mixture into hazard category Type A might include results from Test A and Test B or alternatively results from Test A, Test C and Test D. Results from Test A alone are insufficient to classify a substance or mixture into Type A.

Test series H is used to determine the SADT. The SADT is used in criteria for Types F and G. The SADT is dependent on the nature of the self-reactive product, and the volume and heat-loss characteristics of the packaging. Therefore, the "SADT is only valid for the substance or mixture as tested and when handled properly. Mixing the self-reactive substances and mixtures with other chemicals, or contact with incompatible materials (including incompatible packaging) may reduce the thermal stability due to catalytic decomposition, and lower the SADT. This may increase the risk of decomposition and has to be avoided." (ECHA Guidance, 2017, paragraph 2.8.4.3.1)

The SADT decreases with increasing package size and with increasing efficiency of the insulation on the package. "The test selected shall be conducted in a manner which is representative, both in size and material, of the package." (GHS, seventh revised edition, 2017, paragraph 2.8.2.3)

An SADT must be determined in order to decide if a substance or mixture:

1. conforms to the requirements of Types F or G, when appropriate, or
2. meets the SADT criterion for self-reactive substances, when

(Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.4.1.3)

In addition, an SADT is required to determine if a substance or mixture should be subject to temperature control during transport, storage and handling.

Discussion of subsection 7.8.1(3) of the Hazardous Products Regulations

This exclusion is listed in paragraph 2.8.2.1(e) of the GHS. See also discussion of subsection 7.8.1(1) of the HPR for information on other exclusions.

Hazard Communication

The symbols, signal words as well as hazard and precautionary statements for "Self-Reactive Substances and Mixtures" are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017) as follows:

• Type A on p. 318,
• Type B on p. 319, and
• Types C to F, on p. 320
• Type G has no symbol, signal word, hazard or precautionary

Classification of Self-Reactive Substances or Mixtures Example

Example 7.8.1:

A white solid is suspected of being a self-reactive substance and is tested according to the appropriate UN tests.

The test methods for determining the type of self-reactive substance or mixture are performed using the Manual of Tests and Criteria, Part II, Test Series A to H. The tests are designed to provide the information necessary to apply the principles for classification. In the following example, the results of the tests are assessed in alphanumeric order; however, the tests are performed in the order recommended under sub-section 20.4.5 of the United Nations Manual of Tests and Criteria, seventh revised edition, 2019.

Available data:

• White solid
• Molecular formula: C2H4N4O2
• Apparent density: 945 kg/m³
• Particle size: < 400 μm

Table 7.3 Test results

Test Name	Observation	Result
Test series A - Detonation propagation [BAM 50/60 steel tube test]	30 cm of tube fragmented, unreacted substance remained in the tube	Partial propagation of detonation
Test series B - Detonation as packaged	Not applicable	-
Test series C - Deflagration propagation [Time/pressure test]	Test conducted on 5 g of sample 3 times and the time it took for the pressure to rise from 690 kPa to 2,070 kPA was noted (3.0 s, 2.5 s, 2.7 s). Shortest recorded time (2.5 s) is used for result.	Test result/criteria: Yes, it can propagate a deflagration but slowly, because the time for pressure to rise from 690 kPa to 2,070 kPA is greater than or equal to 30 ms.
Test series C - Deflagration propagation [Deflagration test]	Test conducted 2 times on 265 cm3 of sample at 50 °C, and the reaction rate noted for each (0.71 mm/s, 0.65 mm/s). Shortest recorded rate (0.65 mm/s) is used for result.	Yes, it can propagate the deflagration but slowly, because the deflagration rate is less than or equal to 5.0 mm/s and greater than or equal to 0.35 mm/s. Based on both series C tests, it can propagate the deflagration but slowly.
Test series D - Deflagration as packaged	Not applicable	-
Test series E - Effect of heating under confinement [Koenen test]	Tested 26.0 g of sample. Limiting diameter of 3.5 mm (time to reaction 19.0 s, duration of reaction 22 s)	Violent effect of heating under confinement because the limiting diameter is greater than or equal to 2.0 mm.
Test series E - Effect of heating under confinement [Dutch Pressure Vessel test]	Tested 10.0 g of sample. Limiting diameter of 10.0 mm (time to reaction 110 s, duration of reaction 4 s)	Violent effect of heating under confinement because rupture of the disc with an orifice of 9.0 mm or greater and a sample mass of 10.0 g. Based on both series E tests the effect of heating under confinement is Violent
Test series F - Explosive Power	Not applicable	-
Test series G - (explosion) as packaged [Thermal explosion test in the package]	Tested 25 kg of substance in packaging type 6HG2. Observed fumes only, no fragmentation of the package.	No explosion: No fragmentation or a fragmentation into no more than 3 pieces shows that the substance does not explode in the package. Chemical is classified as a self-reactive Type C.
Test series H - Thermal stability [United States SADT test]	Not applicable	-

Classification

The white solid, substance XYZ, is classified as Self-Reactive, Type C: Any self-reactive liquid or solid substance or mixture possessing explosive properties when the chemical as packaged cannot detonate or deflagrate rapidly or undergo a thermal explosion will be defined as self-reactive substance Type C.

Rationale

The classification of a self-reactive liquid or solid substance or mixture must be based on the results from testing performed in accordance with test series A to H of the Manual of Test and Criteria which must be assessed against the criteria in the table to subsection 7.8.1(2) and subsection 7.8.1(3).

Substance XYZ is a solid that possesses explosive properties, which neither detonates nor deflagrates rapidly nor undergoes a thermal explosion as packaged (item 3 of table to subsection 7.8.1(2)).

Subpart 9 Pyrophoric Liquids

Discussion – Pyrophoric Liquid

The adjective "pyrophoric" describes the ability of a substance or mixture to spontaneously ignite or combust in air, without a supplied spark, flame, or the addition of heat. The reaction is exothermic and almost instantaneous (within minutes) (ECHA Guidance, 2017, paragraph 2.9.1). This instantaneous reaction differentiates pyrophoric substances and mixtures "…from self-heating substances and mixtures, which also react spontaneously with air but only when in larger amounts and after an extended period of time (hours or days)." (ECHA Guidance, 2017, paragraph 2.9.3) For additional information on self-heating substances and mixtures see Subpart 11 of Part 7 of the HPR – Self Heating Substances and Mixtures.

Classification in a Category of the Class

Discussion of section 7.9.1 of the Hazardous Products Regulations

In the event where data of the types referred in subparagraphs 2.1 (a) (ii), (iii) or (iv) of the HPR are available, such as experience in production or handling showing that the substance or mixture does not seem to ignite spontaneously on coming into contact with air at normal temperatures (that is, the substance seems to be stable at room temperature for prolonged periods of time (days)), this type of data, if feasible, must be assessed against the criteria in the table to section 7.9.1 in order to determine if the liquid meets the criteria to be classified in this hazard class.

However, a liquid known to be pyrophoric based on experience must be considered for classification in the Pyrophoric Liquids hazard class using the criteria in the table to section 7.9.1, as would a liquid that spontaneously ignites upon opening its container.

Certain chemical groups and their derivatives are more likely to be pyrophoric. These chemical groups include:

• organo-metals,
• organo-metalloids,
• organo-phosphines,
• hydrides, and
• haloacetylene derivatives (ECHA Guidance, 2017, paragraph 9.1).

More information on pyrophoric substances can be found in Bretherick's Handbook of Reactive Chemical Hazards, eighth edition, 2017.

Testing

If testing is done, it must be performed using test N.3: Test method for pyrophoric liquids of sub-section 33.4.5 of Part III of the Manual of Tests and Criteria (seventh revised edition, 2019, sub-section 33.4.5).

The procedure consists of 2 parts. In the first part, 0.5 ml of the liquid is exposed to air to determine if ignition occurs within 5 minutes. If no ignition occurs, the procedure is performed again until a positive result is obtained or a total of 6 negative attempts have been made.

The second part of the test is only performed if negative results were obtained in the first part of the test. In this part, 0.5 ml test sample is applied to a dry filter paper to see if the liquid will char or ignite the filter paper. The test is repeated for a total of 3 times using fresh filter paper each time unless a positive result is obtained earlier. Refer to the Manual of Tests and Criteria for a complete description of the method and analysis of the test results.

Note: The mechanism of oxidation is, in general, very complex, and the humidity of air might influence the rate of reaction. Certain metals will not react in dry air but will react almost instantaneously in moist air. Since the humidity of the air might influence the rate of reaction, false negative results are possible if the test is performed in an extremely dry environment (ECHA Guidance, 2017, paragraph 2.9.4.4).

A positive result in either part of the test procedure is sufficient to classify the liquid into Pyrophoric Liquids — Category 1.

Hazard Communication

The symbol, signal word as well as hazard and precautionary statements for "Pyrophoric Liquids" Category 1 are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017) on p. 321.

Subpart 10 Pyrophoric Solids

Discussion – Pyrophoric Solid

The adjective "pyrophoric" describes the ability of a substance or mixture to spontaneously ignite or combust in air, without a supplied spark, flame, or the addition of heat. The reaction is exothermic and almost instantaneous (within minutes) (ECHA Guidance, 2017, paragraph 2.10.1). This instantaneous reaction differentiates pyrophoric substances and mixtures "…from self-heating substances and mixtures, which also react spontaneously with air but only when in larger amounts and after an extended period of time (hours or days)." (ECHA Guidance, 2017, paragraph 2.10.3). For additional information on self-heating substances and mixtures see Subpart 11 of Part 7 of the HPR – Self Heating Substances and Mixtures.

Classification in a Category of the Class

Discussion of section 7.10.1 of the Hazardous Products Regulations

In the event where data of the types referred in subparagraphs 2.1 (a) (ii), (iii) or (iv) of the HPR are available, such as experience in production or handling showing that the substance or mixture does not seem to ignite spontaneously on coming into contact with air at normal temperatures (that is, the substance or mixture seem to be stable at room temperature for prolonged periods of time (days)), this type of data, if feasible, must be assessed against the criteria in the table to section 7.10.1 in order to determine if the solid meets the criteria to be classified in this hazard class.

However, a solid known to be pyrophoric based on experience must be considered for classification in the Pyrophoric Solids hazard class using the criteria in the table to section 7.10.1, as would a solid that spontaneously ignites upon opening its container.

Certain chemical groups and their derivatives are more likely to be pyrophoric. These chemical groups include:

• organo-metals,
• organo-metalloids,
• organo-phosphines,
• hydrides,
• haloacetylene derivatives,
• complex acetylides, and
• powders or fine metal particles of metals (ECHA Guidance, 2017, paragraph 2.9.1).

More information on pyrophoric substances can be found in Bretherick's Handbook of Reactive Chemical Hazards eighth edition, 2017.

Testing

If testing is done it must be performed using test N.2: Test Method for pyrophoric solids of sub-section 33.4.4 of Part III of the Manual of Tests and Criteria. The procedure consists of pouring 1 to 2 ml of powder onto a non-combustible surface and observing whether the substance or mixture ignites within 5 minutes. If no ignition occurs, the procedure is performed again until a positive result is obtained or a total of 6 negative attempts have been made. Refer to the Manual of Tests and Criteria for a complete description of the method and analysis of the test results.

Note: The mechanism of oxidation is, in general, very complex, and the humidity of air might influence the rate of reaction. Certain metals will not react in dry air but will react almost instantaneously in moist air. Since the humidity of the air might influence the rate of reaction, false negative results are possible if the test is performed in an extremely dry environment (ECHA Guidance, 2017, paragraph 2.10.4.4).

A positive result in the test procedure is sufficient to classify the solid into Pyrophoric Solids — Category 1.

Hazard Communication

The symbol, signal word as well as hazard and precautionary statements for "Pyrophoric Solids" Category 1 are specified in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017) on p. 322.

Subpart 11 Self-Heating Substances and Mixtures

Discussion – Self-Heating

"Self-heating" is the gradual reaction of a substance or mixture with oxygen in the air to produce heat (that is, an exothermic reaction). The reaction rate may be very slow initially (induction period). If the heat does not dissipate into the environment as quickly as it is generated, the heat can accumulate, and this accumulation can result in an increase in the temperature of the substance or mixture, leading to self-ignition and combustion (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraph 2.4.3.1.2).

Classification in a Category of the Class

Discussion of subsection 7.11.1(1) of the Hazardous Products Regulations

In keeping with the definition given in paragraph 2.11.1 of the GHS, Pyrophoric Solids and Pyrophoric Liquids need not be considered for classification as Self-heating Substances and Mixtures.

Both pyrophoric and self-heating reactions are exothermic and involve spontaneous ignition in the presence of air. However, pyrophoric reactions only require small quantities of a substance or mixture to occur and are almost instantaneous, occurring in minutes. Self-heating reactions require larger amounts (kilograms) and an extended period of time (hours or days) to occur.

Discussion of subsection 7.11.1(2) of the Hazardous Products Regulations

Paragraph 2.11.4.1 of the ECHA Guidance on the Application of the CLP Criteria, July 2017 provides the following guidance:

• Self-heating is a very complex phenomenon which is influenced by many parameters some of them being volume, temperature, particle shape and size, heat conductivity and bulk Therefore, self-heating behaviour cannot be predicted by any theoretical models. "In some cases, properties might even differ between producers of seemingly very similar substances or mixtures. Differences in self-heating behaviour are especially to be anticipated where surface treatment occurs in the production process. Hence, all data sources should be carefully evaluated with regard to reliability and scientific validity." (ECHA Guidance, 2017, paragraph 2.11.4.1)

Note: The criteria are based on the self-ignition temperature of charcoal, which is 50°C for a sample cube of 27 m³. Substances and mixtures with a temperature of spontaneous combustion higher than 50 °C for a volume of 27 m³ should not be classified in this hazard class. Substances and mixtures with a self-ignition temperature higher than 50 °C for a volume of 450 litres should not be classified in Category 1 of this hazard class (GHS, seventh revised edition, 2017, paragraph 2.11.2.2, Note 2).

Testing

In many instances, a simple screening test can be used to determine whether self-heating occurs, provided that the results of the test can be adequately correlated with the classification test N.4 of sub-section 33.4.6 of Part III of the Manual of Tests and Criteria and that an appropriate safety margin is applied. The GHS (seventh revised edition, 2017, paragraph 2.11.4.2) provides the following examples of screening tests:

1. The Grewer Oven test (verein deutscher ingenieure - the Association of German Engineers (VDI) guideline 2263, part 1, 1990, Test methods for the Determination of the Safety Characteristics of Dusts) is designed to determine the relative auto-ignition temperature of a dust sample by heating the same amount of test sample and reference power (graphite) in a hot air stream at a rate of 1°C/min. The surrounding temperature at which the test sample temperature starts to rise faster than that of the inert reference sample is taken as the (relative) auto-ignition temperature of the sample. The classification procedure into a self-heating category may not apply to substances or mixtures with an onset temperature 80 °Kelvin above the reference temperature for a volume of 1 litre.
2. The Bulk Powder Screening Test (Gibson, N., et al. Evaluation of the fire and explosion risks in drying powders, Plant Operations Progress, 4 (3), 181-189, 1985) is used to characterize the thermal decomposition of a powder. The procedure of classification into a self-heating category may not apply to substances or mixtures with an onset temperature 60 °Kelvin above the reference temperature for a volume of 1 litre.

If self-heating behaviour cannot be ruled out by a screening test, then further testing using the classification test N.4 as specified in subsection 7.11.1(2) can be undertaken. This method uses 25 mm or 100 mm cubes of sample at temperatures of 100 °C, 120 °C or 140 °C to see if they undergo spontaneous ignition or dangerous self-heating as indicated by a 60 °C rise in temperature over the oven temperature within 24 hours. (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 33.4.6)

Refer to the Manual of Tests and Criteria for a complete description of the method and analysis of the test results.

Prescribed classification

As per subsection 2(3) of the HPR, there are several substances listed as Self-heating Substances and Mixtures — Category 1 in Schedule 4 of the HPR "Prescribed Classification". For further information, please refer to the discussion of subsections 2(3), 2(4), and 2(5) of the HPR.

Discussion of subsection 7.11.1(3) of the Hazardous Products Regulations

This exclusion corresponds to Note 2 of Table 2.11.1 of the seventh revised edition of GHS.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for "Self-heating Substances and Mixtures" Category 1 and Category 2 are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, p. 323).

Classification of Self-Heating Substances and Mixtures Examples

Example 7.11.1:

An inorganic black powder is suspected of being a self-heating substance and is tested according to the Manual of Tests and Criteria, Part III, sub-section 33.4.6, Test method N.4: Test method for self-heating substances.

Available data

• Inorganic black powder, transported in packages of 500 liters (0.5 m³)
• Tested per UN Test method N.4 with the following results:
  • A positive result using a 100 mm sample cube at 140 °C (284 °F)
  • A negative result using a 25 mm sample cube at 140 °C (284 °F)

According to the procedure, if a positive result is obtained at 140 °C (284 °F) in a 100 mm sample cube, but not in a 25 mm sample cube, then an additional test with the substance in a 100 mm sample cube should be performed based on the packaging and quantity being transported.

Below are the results of this additional test:

• A positive result using a 100 mm sample cube at 120 °C (248 °F) and the solid is packed in packages of more than 450 liters

Classification

The chemical meets the criteria for classification for Self-Heating Substances and Mixtures — Category 2.

Rationale

The substance is a powder.

1. Does a 100 mm sample cube undergo self-heating when tested at 140 °C (284 °F)?

   ANSWER: Yes. A positive result was obtained.

2. Does a 25 mm sample cube undergo self-heating when tested at 140 °C (284 °F)?

   ANSWER: No. A negative result was obtained.

3. Is it packaged in more than 3 m³?

   ANSWER: No. It is transported in packages of 500 liters (0.5 m³).

4. Does a 100 mm sample cube undergo self-heating when tested at 120 °C (248 °F)?

   ANSWER: Yes. A positive result was obtained.

5. Is it packaged in more than 450 liters?

   ANSWER: Yes. It is transported in packages of 500 liters.

Example 7.11.2:

There is a substance with a UN number of 3183 that has not been mixed with other ingredients. UN number 3183 is prescribed a classification of Self-heating Substances and Mixtures — Category 1 in Schedule 4 of the HPR "Prescribed Classification". The substance has not been mixed with one or more ingredients and is classified in the most severe category of the classification table of the hazard class. Therefore, as per subsection 2(3) of the HPR, this substance is classified as Self-heating Substances and Mixtures — Category 1. Subsection 2(4) of the HPR is not triggered.

Subpart 12 Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases

Discussion – Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases

Some substances and mixtures at normal ambient temperature (20 °C) and in contact with water or moisture (for example, damp, humid air) emit gases which might be flammable, toxic, or both. Classification of such substances and mixtures should be considered in particular for both the Physical Hazard Class "Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases", Subpart 12 of Part 7 of the HPR and the Health Hazard Class "Acute Toxicity", Subpart 1 of Part 8 of the HPR.

Subpart 12 of Part 7 of the HPR is concerned only with the generation of flammable gases following the contact of a substance or mixture with water. Flammable gases pose a physical hazard to workers by forming explosive mixtures with air that can be easily ignited by ordinary sources of ignition (for example, sparking hand tools). (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021, paragraph 2.4.4.1)

If contact with water results in the evolution of a toxic gas (for example, hydrogen chloride) then the substance or mixture might meet the criteria for classification in the Acute Toxicity hazard class. See subsection 8.1.1(2) of the HPR and section 8.1.2 of the HPR for further information.

Classification in a Category of the Class

Discussion of subsection 7.12.1(1) of the Hazardous Products Regulations

Under subsection 7.12.1(1) of the HPR, the classification procedure for this hazard class does not apply to a substance or mixture:

• whose chemical structure does not contain any metals or metalloids;
• where experience in production or handling shows that it does not react with water (for example, the chemical is manufactured with water or washed with water and no reactions have occurred); or
• that is soluble in water to form a stable

If any of the exclusion criteria are met, the substance or mixture need not be assessed under this hazard class.

Discussion of subsection 7.12.1(2) of the Hazardous Products Regulations

Subsection 7.12.1(2) of the HPR outlines the requirements to classify a substance or mixture into a category under "Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases" and applies to both solids and liquids.

The following types of data should be considered when classifying a substance (ECHA Guidance, 2017, paragraph 2.12.4.1) or mixture in the Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases hazard class:

• chemical structure - check to see if the substance or mixture contains
  • certain chemical families which are often hazardous in contact with water and could meet the requirements for classification, including
    • alkali metals (for example, lithium, sodium)
    • metal hydrides (for example, sodium hydride, lithium hydride)
    • complex metal hydrides (for example, lithium aluminum hydride, sodium aluminum hydride)
    • metal phosphides (for example, aluminum phosphide, calcium phosphide)
    • certain metal powders (for example, aluminium and magnesium powders, zinc dust)

A comprehensive list of substances that should be considered for classification in this hazard class can be found in Bretherick's Handbook of Reactive Chemical Hazards, eighth edition, 2017.

• in the case of solids, the particle size and friability (the ability of a solid to be easily broken down into smaller pieces) – this characterization of physical state is especially important if testing is undertaken.
  • Under the UN test N.5 of sub-section 33.5.4 of Part III of the Manual of Tests and Criteria, samples of solids containing particles of less than 500 um diameter and that constitute more than 1% (mass) of the total solid, or of solids that are friable, should be ground to a powder before testing to allow for a reduction in particle size that could occur during handling and transport. (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 33.5.4)
• chemical identity and flammability of the emitted gas, which is used to decide whether the evolved gas is flammable or not.

Testing

If testing is done it must be performed using test N.5 of sub-section 33.5.4 of Part III of the Manual of Tests and Criteria. This test method can be applied to both solids and liquids and is intended to determine whether the reaction of a substance or mixture with water leads to the development of a dangerous amount of gas which may be flammable. If spontaneous ignition occurs at any stage then no further testing is necessary and the substance or mixture would be classified in Category 1 of this hazard class. Refer to the Manual of Tests and Criteria for a complete description of the method and analysis of the test results. (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 33.5.4)

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, pp. 324-325).

Classification of Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases Example

Example 7.12.1:

A liquid is suspected of being a chemical which, in contact with water, emits flammable gas.

The liquid is tested to determine whether any gas is evolved, if spontaneous ignition of the gas occurs, and if there is evolution of flammable gas at a rate greater than 1 liter per kilogram of the chemical per hour.

Tests are performed using the Manual of Tests and Criteria, Part III, sub-section 33.5.4, Test method N.5: "Test method for substances which in contact with water emit flammable gases."

Available data

• Liquid contains an organometallic.
• The chemical reacts slowly with water and emits a gas known to be flammable which is not liable to ignite spontaneously.
• Chemical was tested for seven hours at ambient temperature per UN Test 5 "Test method for substances which, in contact with water, emit flammable gases." Test results showed:
  • A maximum rate of evolution of 15 liters per kilogram (L/kg) substance per hour of flammable gas.
  • The gas did not spontaneously ignite in any step of the test

Classification

The liquid meets the criteria for Substances and Mixtures Which, in Contact with Water, Emit Flammable Gases — Category 3.

Rationale

1. Does the liquid react with water at ambient temperature and produce a gas that is liable to ignite spontaneously?

   ANSWER: No

2. Does the liquid react with water at ambient temperature such that the rate of evolution of flammable gas is ≥ 10 L/kg of liquid or solid over any one minute?

   ANSWER: No

3. Does the liquid react with water at ambient temperature to ignite spontaneously in any step of the test procedure?

   ANSWER: No

4. Does the liquid react with water at ambient temperature such that the maximum rate of evolution of flammable gas is ≥ 20 L/kg of liquid or solid per hour?

   Answer: No

5. Does the liquid react with water at ambient temperature such that the maximum rate of evolution of flammable gas is ≥ 1 L/kg of liquid or solid per hour?

   Answer: Yes, 15 L/kg of liquid or solid per hour.

The liquid meets the Category 3 criteria: Any chemical which reacts with water at ambient temperatures such that the maximum rate of evolution of flammable gas is greater than 1 liter per kilogram of chemical per hour, and which does not meet the criteria for Categories 1 and 2.

Subpart 13 Oxidizing Liquids

Discussion – Oxidizing Liquids

In general terms, an oxidizer is a chemical that brings about an oxidation reaction. An oxidizing reaction means:

• the oxidizer provides oxygen to the substance being oxidized (in which case the oxidizer has to be oxygen or contain oxygen), or
• the oxidizer receives electrons from the substance being oxidized (for example, bromine pentafluoride is an oxidizer based on electron-transfer, even though it does not contain oxygen).

Oxidizers can initiate or greatly accelerate the combustion of other materials. The most common oxidizer is atmospheric oxygen.

Classification in a Category of the Class

Discussion of subsection 7.13.1(1) of the Hazardous Products Regulations

For the interpretation of subsection 7.13.1(1) of the HPR, an organic liquid can be either an organic substance or mixture, while an inorganic liquid can be either an inorganic substance or mixture. Examples of halogen atoms include fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Any substance or mixture that meets the above exclusion criteria can be considered as not having oxidizing properties. Therefore, the substance or mixture need not be classified as an oxidizing liquid.

Discussion of subsection 7.13.1(2) of the Hazardous Products Regulations

The available data must first be compared against the criteria for exclusion from classification in this class listed in subsection 7.13.1(1) of the HPR. If any of the exclusion criteria are met, the substance or mixture need not be assessed under this class.

If none of the exclusion criteria are met, the available data are assessed against the criteria in the table to subsection 7.13.1(2).

It must be noted that a hazard category cannot be assigned based on the chemical structure.

Testing

If testing is done it must be performed using test O.2 of sub-section 34.4.2 of Part III of the Manual of Tests and Criteria. The test measures the time for the pressure to rise between 2 specific values (690 kPa – 2070 kPa) and compares it to a standard.

Note that the higher the rate of pressure rise (that is, a shorter time of pressure rise), the stronger the oxidizing capability of the liquid tested.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for "Oxidizing Liquids" are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017); for Oxidizing Liquids — Category 1 on p. 326, and for Oxidizing Liquids — Category 2 and 3 on p. 327.

Classification of Oxidizing Liquids Example

Example 7.13.1:

Tests are performed using the Manual of Tests and Criteria, sub-section 34.4.2, Test Method O.2: "Test for oxidizing liquids."

A liquid suspected of being an oxidizing liquid is tested to determine whether a mixture of the substance and cellulose spontaneously ignites. The mean time taken for the pressure to rise from 690 kPa to 2,070 kPa is compared with those of the reference mixtures. The 3 reference mixtures are: 50% perchloric acid and cellulose, 40% aqueous sodium chlorate solution and cellulose and 65 % aqueous nitric acid and cellulose. 5 trials are performed with the mixture and each of the reference mixtures. The time taken for the pressure rise from 690 kPa to 2,070 kPa is noted. The mean time interval is used for classification.

Available data

• 2.5 g of the liquid to be tested is mixed with 2.5 g of dried cellulose. The mixture did not spontaneously ignite.
• The mixture is heated, and the time taken for the pressure rise from 690 kPa to 2,070 kPa is measured. The mean pressure rise time for 5 trials is 4,210 seconds (s).
  • The test sample exhibited a pressure rise ≥ 2,070 kPa gauge.
  • The mean pressure rise time for the reference mixture containing 50% perchloric acid and cellulose is 3,085 s.
  • The mean pressure rise time for the reference mixture containing 40% aqueous sodium chlorate and cellulose is 4,050
  • The mean pressure rise time for the reference mixture containing 65% aqueous nitric acid and cellulose is 4,767

Classification

The chemical meets the criteria to be classified in Oxidizing Liquids — Category 3.

Rationale

The substance is a liquid.

1. Does a 1:1 mixture, by mass, of substance and cellulose tested, exhibit a pressure rise ≥ 2,070 kPa gauge?

   ANSWER: Yes. The test sample exhibited a pressure rise of ≥ 2,070 kPa gauge.

2. Does a 1:1 mixture, by mass, of substance and cellulose tested, spontaneously ignite or exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 50% perchloric acid and cellulose?

   ANSWER: No. Absence of spontaneous ignition and the mean pressure rise time for the liquid test substance is 4,210 s, which is greater than 3,085 s for perchloric acid.

3. Does a 1:1 mixture, by mass, of substance and cellulose tested, exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 40% aqueous sodium chlorate and cellulose?

   ANSWER: No. The mean pressure rise time for the liquid test substance is 4,210 s, which is greater than 4,050 s for 40% aqueous sodium chlorate.

4. Does a 1:1 mixture, by mass, of substance and cellulose tested, exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 65% aqueous nitric acid and cellulose?

   ANSWER: Yes. The mean pressure rise time for the liquid test substance is 4,210 s, which is less than 4,767 s for 65% aqueous nitric acid.

The liquid meets the criteria for Oxidizing Liquids — Category 3 and does not meet the criteria for Category 1 or 2.

Subpart 14 Oxidizing Solids

Discussion – Oxidizing Solids

In general terms, an oxidizer is a chemical that brings about an oxidation reaction. An oxidizing reaction means:

• the oxidizer provides oxygen to the substance being oxidized (in which case the oxidizer has to be oxygen or contain oxygen), or
• the oxidizer receives electrons from the substance being oxidized.

Oxidizers can initiate or greatly accelerate the combustion of other materials. The most common oxidizer is atmospheric oxygen.

Classification in a Category of the Class

Discussion of subsection 7.14.1(1) of the Hazardous Products Regulations

Under subsection 7.14.1(1) of the HPR, the classification procedure for this hazard class need not be applied to a solid that is:

• an organic substance or mixture:
  1. that does not contain oxygen (O), fluorine (F) or chlorine (Cl), or
  2. that contains oxygen, fluorine or chlorine and these elements are chemically bonded only to carbon (C) or hydrogen (H).
• an inorganic substance or mixture:
  3. that does not contain oxygen or halogen atoms (for example, fluorine, chlorine, bromine (Br), iodine (I)).

Any substance or mixture that meets the above exclusion criteria can be considered as not having oxidizing properties. Therefore, no testing is needed, and the substance or mixture does not need to be classified as an oxidizing solid.

Discussion of subsection 7.14.1(2) of the Hazardous Products Regulations

The available data must first be compared against the criteria for exclusion from classification in this class listed in subsection 7.14.1(1) of the HPR. If any of the exclusion criteria are met, the substance or mixture need not be assessed under this class.

If none of the exclusion criteria are met, the available data are assessed against the criteria in table to subsection 7.14.1(2).

It must be noted that a hazard category cannot be assigned based on the chemical structure.

Testing

If testing is done it must be performed using test O.1 of sub-section 34.4.1 of Part III of the Manual of Tests and Criteria or test O.3 of sub-section 34.4.3 of that Part. These tests measure the time a mixture of the solid substance and cellulose takes to burn as compared to a reference material. The tests are repeated several times and an average burning time is recorded.

Note that the faster the burning time, the stronger the oxidizing capability of the solid tested.

Test O.3 was developed due to dangerous reactions that sometimes occur with Test O.1.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Oxidizing Solids are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017); for Oxidizing Solids — Category 1 on p. 328, and for Oxidizing Solids — Category 2 and 3 on p. 329. Note in the seventh revised edition of the GHS page 328 reads "Oxidizing Liquids (Chapter 2.13)". The corrigendum to the seventh revised edition of the GHS corrects this to read "Oxidizing Solids (Chapter 2.14)".

Classification of Oxidizing Solids Example

Example 7.14.1:

Tests are performed using the Manual of Tests and Criteria, Part III, sub-section 34.4.1, Test Method O.1: "Test for oxidizing solids."

A solid powder substance suspected of being an oxidizing solid is tested to determine whether the mixture of substance and cellulose ignites and burns, and to compare the mean burning time with those of reference mixtures.

Tests require that the substance in question be mixed with dry fibrous cellulose in ratios of 1:1 and 4:1, by mass, of sample to cellulose.

The burning characteristics of these mixtures are compared with the standard reference mixtures, 3:2, 2:3 and 3:7 ratios, by mass, of potassium bromate to cellulose. 5 trials are performed on the test substance in each of the sample to cellulose ratios. 5 trials are performed with each reference mixture.

Available data

Test data/results

• The data for the 4:1 and 1:1 ratio of the test mixtures are
  • The mean burn time for the 4:1 ratio of the test mixture to cellulose is 105 s
  • The mean burn time for the 1:1 ratio of the test mixture to cellulose is 340 s
• The data for the standard reference mixtures, 3:2, 2:3 and 3:7 ratios of potassium bromate to cellulose are
  • The mean burn time for the 3:2 ratio of potassium bromate to cellulose is 4 s
  • The mean burn time for the 2:3 ratio of potassium bromate to cellulose is 54 s
  • The mean burn time for the 3:7 ratio of potassium bromate to cellulose is 100 s

Classification

The solid substance does not meet the criteria for oxidizing solids, so it is not classified as an oxidizing solid.

Rationale

The substance is a solid

1. Does a 4:1 or 1:1 sample-to-cellulose ratio, by mass, tested, exhibit a mean burning time less than or equal to the mean burning time of a 3:2 mixture, by mass, of potassium bromate and cellulose?

   ANSWER: No. The mean burn times for both the 4:1 and 1:1 solid substance sample-to- cellulose ratios (105 s, 340 s) are greater than the mean burning time of the 3:2 mixture, by mass, of potassium bromate and cellulose (4 s).

2. Does a 4:1 or 1:1 sample-to-cellulose ratio, by mass, tested, exhibit a mean burning time less than or equal to the mean burning time of a 2:3 mixture, by mass, of potassium bromate and cellulose?

   ANSWER: No. The mean burn times for both the 4:1 and 1:1 solid substance sample-to- cellulose ratios (105 s, 340 s) are greater than the mean burning time of the 2:3 mixture, by mass, of potassium bromate and cellulose (54 s).

3. Does a 4:1 or 1:1 sample-to-cellulose ratio, by mass, tested, exhibit a mean burning time less than or equal to the mean burning time of a 3:7 mixture, by mass, of potassium bromate and cellulose?

   ANSWER: No. The mean burn times for both the 4:1 and 1:1 solid substance sample-to- cellulose ratios (105 s, 340 s) are greater than the mean burning time of the 3:7 mixture, by mass, of potassium bromate and cellulose (100 s).

Consequently, this solid substance is not classified as an oxidizing solid.

Subpart 15 Organic Peroxides

Discussion – As Packaged

The methodology of the test series (that is, series B, D, G and H) used to classify organic peroxides requires that the substance or mixture be tested in the condition and form in which it is offered for transport or "as packaged" (Manual of Tests and Criteria, seventh revised edition, 2019, sections 22, 24, 27 and 28 (Test Series B, D, G and H, respectively)).

Discussion - Explosive Properties

The above definition for explosive properties is derived from the following statement from the GHS:

"An organic peroxide is regarded as possessing explosive properties when in laboratory testing the formulation is liable to detonate, to deflagrate rapidly or to show a violent effect when heated under confinement." (GHS, seventh revised edition, 2017, paragraph 2.15.1.2)

The test methods are included in the definition given in section 7.15 of the HPR because results from these tests are used to conclude whether a substance or mixture has explosive properties for the purposes of classification in the Organic Peroxides hazard class.

Discussion - Organic Peroxides

Organic peroxides may be solid or liquid organic chemicals (that is, chemicals containing carbon) that are characterized by a weak oxygen-oxygen (-O-O-) bond (also called a peroxy group or peroxide group). This bond can break or decompose easily, releasing heat (that is, exothermic reaction). The rate of decomposition increases with increasing temperature. Decomposition can also be initiated by heat, mechanical shock, friction, or contaminants such as amines, metal ions (by themselves or as a result of contact with metal surfaces), strong acids and bases, and strong reducing and oxidizing agents.

In addition to being thermally unstable, organic peroxides "…may have 1 or more of the following properties:

1. be liable to explosive decomposition;
2. burn rapidly;
3. be sensitive to impact or friction;
4. react dangerously with other substances." (GHS, seventh revised edition, 2017, paragraph 2.15.1.1)

In general, organic peroxides have weak or no oxidizing properties but may be flammable or emit a flammable gas when heated (ECHA Guidance, 2017, paragraph 2.15.3).

Other applicable definitions

The following term is used in this chapter but its definition appears under Part I, Interpretation of the HPR:

Discussion – SADT

When the oxygen-oxygen bond of an organic peroxide decomposes or breaks, it generates free radicals and heat. If the heat does not dissipate into the environment as quickly as it is generated, the resulting increase in temperature will further intensify the rate of decomposition. Unchecked, the temperature can increase exponentially to a point where decomposition cannot be stopped. This reaction creates a dangerous situation known as self-accelerating decomposition.

The SADT is the lowest temperature at which a packaged organic peroxide will undergo a self-accelerating decomposition. "The SADT and SAPT are measures of the combined effect of the ambient temperature, reaction kinetics, package size and the heat transfer properties of the substance and its packaging." (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 28.1). The SAPT refers to the self-accelerating polymerization temperature. The SAPT is not a term that is used in the HPR.

Test series H of Part II of the Manual of Tests and Criteria can be used to determine the SADT of a substance or mixture that is an organic peroxide.

Classification in a Category of the Class

Discussion of subsection 7.15.1(1) of the Hazardous Products Regulations

The exclusion criteria described in subsection 7.15.1(1) of the HPR are based on the available oxygen content (also called the active oxygen content) of the organic peroxide(s) under consideration and the content of hydrogen peroxide in a mixture.

The available oxygen content is the amount of oxygen contained in an organic peroxide molecule that is available for forming free radicals. 1 oxygen atom in each peroxide group is considered "active" or available. The concept of available oxygen content is related to the energy content of a formulation. In general, energy content increases with available oxygen content so that the higher the molecular mass of the organic groups, the lower the energy content and, usually, the lower the hazard. The formula for calculating available oxygen content is given in subsection 7.15.1(2) of the HPR.

Discussion of subsection 7.15.1(2) of the Hazardous Products Regulations

The exclusion criteria described in subsection 7.15.1(1) of the HPR require that the available oxygen content (also called the active oxygen content) of the organic peroxide (or peroxides) be calculated.

The formula given in subsection 7.15.1(2) of the HPR takes into account:

• the number of peroxide (or peroxygen) groups in a given organic peroxide where each peroxide group is considered to contain 1 active or available oxygen atom. Using the structural formula of the organic peroxide, the number of peroxide groups (-O-O-) can easily be counted.

Example 1 – Peroxide (or Peroxygen) groups

Figure 23 - Text description

The chemical structure of Methyl ethyl ketone peroxide

From the structural formula given in Figure 23, methyl ethyl ketone peroxide has three (3) peroxide groups.

• the concentration of the organic peroxide as a percentage of the substance or mixture.
• the molecular mass of the organic peroxide.

Example 2 – Calculation of available oxygen content

Figure 24 - Text description

The chemical structure of Benzoyl peroxide

A 25% solution of the organic peroxide benzoyl peroxide does not contain any hydrogen peroxide. To calculate the available oxygen content the following information is required:

n_i - number of peroxide groups. From Figure 24, the number is 1.

c_i – the concentration of the organic peroxide. In this example, it is a 25% solution.

m_i - the molecular mass. The molecular mass can be determined from the molecular formula for benzoyl peroxide C₁₄H₁₀O₄:

14(12 g/mol) + 10(1 g/mol) + 4(16 g/mol)

= 242 g/mol

Solve the formula from 7.15.1 (2) using the above numbers:

16 x (1 x 25)/242

= 1.65%

The available oxygen content is 1.65%, which is greater than 1% and the solution does not contain any hydrogen peroxide. Based on paragraph 7.15.1(1)(a) of the HPR, this organic peroxide solution does not meet the exclusion criteria and must be given further consideration for classification.

Discussion of subsection 7.15.1(3) of the Hazardous Products Regulations

Organic peroxides are classified into 7 categories (Types A to G) according to the degree of danger they present as defined by their ability to detonate, to deflagrate, and to react while heated under confinement. Type A is the most severe hazard category while Type G is the least severe. Additionally, for organic peroxides, their chemical structure (-O-O- bond) and the available oxygen and hydrogen peroxide contents of the mixture (as explained in subsection 7.15.1(1) of the HPR) are also used in classification.

The criteria for Types A, B, and C specify that the organic peroxide be tested "as packaged" since "stronger packaging may result in more violent reactions when the organic peroxide decomposes" (ECHA Guidance, 2017, paragraph 2.15.4.1). The words "in laboratory testing" in Types D, E, F and G criteria imply that the organic peroxide is tested in its non-packaged form. Types F and G have conditional criteria that require testing in a "50 kg package".

Desensitization, mentioned in the criteria for Types F and G, refers to the addition of organic liquids or solids, inorganic solids or water to an organic peroxide to increase the stability of the organic peroxide (UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume I, 22nd revised edition, 2021, sub-section 2.5.3.5.1). For desensitized organic peroxides, the concentration and type of diluent used are important considerations when classifying. Sub-section 2.5.3.5 of the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume I, 22nd revised edition, 2021, provides useful information regarding acceptable diluents.

Testing

If testing is done it must be performed using test series A to H as described in sections 20 to 28 of Part II of the Manual of Tests and Criteria, which are designed to answer the questions given in the flowchart (Figure 20.1 of the Manual of Tests and Criteria – Flowchart scheme for self-reactive substances and organic peroxides) and Decision Logic 2.15 for organic peroxides on p. 104 of the GHS (seventh revised edition, 2017).

Prior to performing tests series A to H, small-scale testing should be performed for the safety of laboratory workers. This involves tests for determining the sensitivity of the substance or mixture to mechanical stimuli (impact and friction), and to heat and flame (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.3). The preliminary testing includes:

1. a falling weight test to determine sensitiveness to impact
2. a friction or impact test to determine the sensitiveness to friction
3. a test to assess thermal stability and the exothermic decomposition energy, and
4. a test to assess the effect of ignition

(Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.3.2)

Thereafter, test series A to H (as applicable) are performed and their results are used to answer questions in the GHS Decision Logic 2.15 for organic peroxides (GHS, seventh revised edition, 2017, p.104) relating to:

• Propagation of detonation
• Propagation of deflagration
• Effect on heating in confinement and
• Thermal stability: SADT

The sequence of test series A to H is based more on assessing results than on the order in which tests are actually conducted. The recommended sequence of laboratory scale testing is test series E, H, F, C and then A, although some tests may not be required as indicated in the introduction to each test series. The package tests of test series B, D, and G only need to be performed if indicated by the results from the corresponding tests in test series A, C, and E (Manual of Tests and Criteria, seventh revised edition, 2019, sub-sections 20.4.6.1 and 20.4.6.2).

Note: The test series A to H described in Part II of the Manual of Tests and Criteria are not equivalent to the classification of Types A to G as specified under subsection 7.15.1(3) of the HPR. For example, from the Decision logic 2.15 for organic peroxides in the GHS, testing to classify a substance or mixture in hazard category Type A might include results from Test A and Test B or alternatively results from Test A, Test C and Test D. Results from Test A alone are insufficient to classify a substance or mixture in Type A.

Test series H is used to determine the SADT. The SADT is used in criteria for Type F and G. The SADT is dependent on the nature of the organic peroxide, and the volume and heat-loss characteristics of the packaging in which the organic peroxide is handled. Therefore, the SADT is only valid for the organic peroxide as tested and when handled properly. Mixing the organic peroxide with other chemicals, or contact with incompatible materials (including incompatible packaging) may reduce the thermal stability due to catalytic decomposition, and lower the SADT. This may increase the risk of decomposition and should be avoided (ECHA Guidance, 2017, paragraph 2.15.4.3.1).

Note that Test Series H does not include the condition of a SADT being less than or equal to 75 °C when transported in a 50 kg package for organic peroxides. Classification based on Test Series H would be consistent with classification expected under the HPR.

The SADT decreases with increasing package size and with increasing efficiency of the insulation on the package. The test selected should be conducted in a manner which is representative, both in size and material, of the package (GHS, seventh revised edition, 2017, paragraph 2.15.2.3).

An SADT must be determined in order to decide if a substance or mixture:

1. conforms to the requirements of Type G, when appropriate, or
2. meets the SADT criterion for organic peroxides, when appropriate

(Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 20.4.1.3)

In addition, an SADT is required to determine if a substance or mixture should be subject to temperature control during transport, storage and handling.

Discussion of subsection 7.15.1(4) of the Hazardous Products Regulations

Testing of a mixture of organic peroxides may be done to determine in which category the mixture will be classified. When testing is not done, the mixture must be classified in the same category as the most hazardous organic peroxide in the mixture. However, if data of the types referred to subparagraph 2.1(a)(i) or (ii) or (b)(i) or (ii) of the HPR are available for the mixture as a whole, and the data support the conclusion that the mixture should be classified in a category that represents a less severe hazard than the most hazardous organic peroxide in the mixture, then the mixture must be classified in the category that represents the less severe hazard.

Discussion of subsection 7.15.1(5) of the Hazardous Products Regulations

In practice, consideration of the SADT applies to Types F and G only (GHS, seventh revised edition, 2017, Decision Logic 2.15). Type F represents a more severe hazard than Type G.

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Organic Peroxides are provided in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, pp. 330-332) as follows:

• Type A on p. 330,
• Type B on p. 331,
• Types C to F on p. 332, and
• Type G has no symbol, signal word, hazard or precautionary statement

Classification of Organic Peroxides Example

Example 7.15.1:

(OSHA Hazard Classification Guidance 2016, pp. 367-370)

A colorless liquid is suspected of being an organic peroxide and is tested according to the tests presented in the Manual of Tests and Criteria, Part II. Organic peroxides, by definition, must contain the molecular structure -O-O-, and must contain a certain level of available oxygen and hydrogen peroxide content.

In the following example, the results of the tests are assessed in alphanumeric order; however, the tests are performed in the order given in sub-section 20.4.5 of the Manual of Tests and Criteria.

Available data

• Colorless liquid
• Composition: technically pure (97%)
• Molecular formula: not available
• Apparent density: 900 kg/m³
• Available oxygen content: 7.18%

Table 7.4 Test results

Test Name	Observation	Result
Test series A - Detonation propagation [BAM 50/60 steel tube test]	Sample conditions: peroxide assay 97% Observations: fragmented part of the tube: 18 cm	Test result/criteria: No propagation of detonation
Test series B - Detonation as packaged	Not applicable	-
Test series C - Deflagration propagation [Time/pressure test]	Test conducted on 5 g of sample 3 times; the time it took for the pressure to rise from 690 kPa to 2,070 kPa was noted. Shortest recorded time (4000 ms) is used for result.	Test result/criteria: Yes, propagates a deflagration slowly, because the time for pressure to rise from 690 kPa to 2,070 kPa is greater than or equal to 30 ms
Test series C - Deflagration propagation [Deflagration test]	Test conducted 2 times on 265 cm3 of sample at 25 °C, and the reaction rate noted for each. Shortest recorded rate (0.74 mm/s) is used for result.	Test result/criteria: Yes, propagates a deflagration slowly, because the deflagration rate is less than or equal to 5.0 mm/s and greater than or equal to 0.35 mm/s. Overall result: Yes, propagates a deflagration slowly
Test series D - Deflagration as packaged	Not applicable	-
Test series E - Effect of heating under confinement [Koenen test]	Tested 60 mm of sample. Limiting diameter: 2.0 mm fragmentation type "F," evaluated as "explosion."	Test result/criteria: Violent effect of heating under confinement because the limiting diameter is greater than or equal to 2.0 mm.
Test series E - Effect of heating under confinement [Dutch Pressure Vessel test]	Tested 10.0 g of sample. Limiting diameter: 6.0 mm (with 10 g)	Test result/criteria: Medium effect of heating under confinement because rupture of the disc with an orifice of 6.0 mm and a sample mass of 10.0 g. Overall result: Violent effect of heating under confinement
Test series F - Explosive Power	Not applicable	-
Test series G - Detonation as packaged [Thermal explosion test in the package]	Tested 30-liter packaging. Observations: no fragmentation of the package (N.F.)	Test result/criteria: No fragmentation or a fragmentation into no more than 3 pieces shows that the substance does not explode in the package.
Test series H - Thermal stability [Heat accumulation storage test; the recommended test for substances transported in packagings, IBCs, or small tanks.]	Tested 380 g of liquid. Half life time of cooling of Dewar vessel with 400 ml DMP: 10.0 hrs (representing substance in package) Observed: Self-accelerating decomposition at 35 °C (95 ºF), no self-accelerating decomposition at 30 °C (86 °F). The SADT is 35 °C (95 °F).	Liquid has a SADT of 35 °C (95 °F).

Evaluation of Data

The liquid has 7.18% available oxygen. The liquid is considered for classification as an organic peroxide since the available oxygen is greater than 1%.

1. Does the chemical in question propagate a detonation? RESULT (Test series A): No
2. Can the chemical in question propagate a deflagration? RESULT (Tests series C): Yes, slowly.
3. What is the effect of heating under confinement? RESULT (Tests series E): Violent.
4. Can it detonate as packaged? RESULT (Tests series G): No.

Classification

The liquid is classified as an Organic Peroxide — Type C.

Rationale

The criteria for Organic Peroxides — Type C in the Table to subsection 7.15(3) of the HPR are the following: A liquid or solid that possesses explosive properties and, as packaged, neither detonates nor deflagrates rapidly, nor undergoes a thermal explosion in that package.

Based on the results of Test series A and G, the liquid does not propagate and does not detonate (explode) as packaged. Test series C results showed that the liquid propagates a deflagration slowly (not rapidly). Test series E results demonstrated that the liquid shows a violent effect when heated under confinement. Comparing these results to the criteria for Organic Peroxides — Types A through G, as set out in the Table to subsection 7.15.1(3) of the HPR, it is concluded that the liquid meets the criteria to be classified as an Organic Peroxide — Type C.

The UN Recommendations on the Transport of Dangerous Goods, Model Regulations, Volume 1, 22nd revised edition, 2021 and the Manual of Tests and Criteria, seventh revised edition, 2019 recommend the use of temperature control for this substance since the SADT (35° C) is less than 50 °C (122 °F).

Subpart 16 Corrosive to Metals

Discussion - Corrosive to Metals

A substance or mixture that is "corrosive to metals" is a substance or mixture that is liable to undergo an irreversible chemical reaction with metals and leads to significant damage or, in some cases, even full destruction of metals.

Many parameters influence the corrosion properties of a substance or mixture, such as the nature of the chemical or the pH.

Classification in a Category of the Class

Discussion of section 7.16.1 of the Hazardous Products Regulations

For the purposes of classification, corrosive to metals will only be considered for substances and mixtures that are liable to corrode either steel or aluminium (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 37.4). This hazard class does not cover substances or mixtures that have the potential to corrode metals other than steel or aluminium.

A substance or a mixture is classified in Corrosive to Metals — Category 1 if it has a corrosion rate on either steel or aluminium surfaces that is > 6.25 mm per year when tested at a temperature of 55 °C.

It is important to note that where an initial test on either a steel or aluminium surface indicates the substance or mixture being tested is corrosive, the follow-up test on the other metal is not required (GHS, seventh revised edition, 2017, section 2.16.2).

2 types of corrosion phenomena are considered when classifying substances or mixtures as corrosive to metals: the uniform corrosion attack and the localized corrosion (for example, pitting corrosion, shallow pit corrosion).

Physical State

For classification, the physical state of the substance or mixture is not specified in the HPR. The classification criteria in section 7.16.1 of the HPR is based on the corrosion rate that is measured according to the test method in Part III, sub-section 37.4 of the Manual of Tests and Criteria, Test C.1, "Test for determining the corrosive properties of liquids and solids that may become liquid as a substance corrosive to metal" (Manual of Tests and Criteria, seventh revised edition, 2019, sub-section 37.4). Although no guidance is provided on how to define "solids that may become liquid", the test is conducted at 55 °C (which is the temperature required in UN Test C.1), therefore, solids with melting points at or below this temperature must be considered for classification in this hazard class.

Testing

If testing is done, it must be performed according to Test C.1 in sub-section 37.4 of Part III of the Manual of Tests and Criteria. This method considers 2 types of corrosion: uniform corrosion attack and localized corrosion (for example, pitting corrosion, shallow pit corrosion). Both types of corrosion are determined using 2 mm thick plates of the following materials:

• For the purposes of testing steel, steel types, S235JR+CR (1.0037 resp. St 37-2), S275J2G3+CR (1.0144 St 44-3), ISO 3574, Unified Numbering System (UNS) G 10200, or SAE 1020
• For the purposes of testing aluminium, non-clad types 7075-T6 or AZ5GU-T6

Refer to the Manual of Tests and Criteria sub-section 37.4 for a complete description of the method, apparatus used and analysis of the test results.

Although the classification is based on a rate of corrosion that is greater than 6.25 mm over the course of a year, in practice, the corrosion rate is measured over a shorter period of time (usually 1 to 4 weeks) and the data is extrapolated to give an annual rate. If the corrosion rate has not been given in mm/year, the mass loss (for uniform corrosion attack) or minimum intrusion depth (for localized corrosion) values must be used for classification in this hazard class (Manual of Tests and Criteria, seventh revised edition, 2019, section 37).

Hazard Communication

As per paragraph 3(1)(c) of the HPR, the symbol, signal word as well as hazard and precautionary statements for Corrosive to Metals — Category 1 are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017, p. 333.

Classification for Corrosive to Metals Example

Example 7.16.1:

For results based on uniform corrosion attack, the mass loss of the most corroded sample is used and compared to Table 37.4.4.1 (reproduced below) of the Manual of Tests and Criteria.

Table 7.5 Minimum mass loss of specimens after different exposure times

Exposure Time	Mass Loss
7 days	13.5 %
14 days	26.5 %
21 days	39.2 %
28 days	51.5 %

The percentage mass loss values are based on a 6.25 mm/year corrosion rate so that a mass loss of greater than 13.5 % at 7 days represents a corrosion rate of greater than 6.25 mm/year.

Available data

Testing of Substance A on non-clad aluminum 7075-T6 using UN Test C.1 results in a mass loss value of 30.8 % at 14 days.

Classification

Substance A must be classified in Corrosive to Metals — Category 1.

Rationale

Using the above table, any mass loss greater than 26.5 % at 14 days represents a corrosion rate of > 6.25 mm/year; therefore, Substance A meets the criteria to be classified in Corrosive to Metals — Category 1.

Subpart 17 Combustible Dusts

The Combustible Dusts hazard class is not a GHS hazard class.

Discussion – Combustible Dusts

Combustible dust hazards involve dusts or other small particles that upon ignition present a fire or explosion hazard when suspended at a sufficient concentration in air or some other oxidizing medium. Under the HPR, products which are sold or imported in dust form and present this physical hazard are included within this hazard class. The Combustible Dusts hazard class in the HPR does not apply to products which will be processed downstream to generate dust in the workplace.

Classification in a Category of the Class

Discussion of section 7.17.1 of the Hazardous Products Regulations

Category

7.17.1 A combustible dust is classified in the category of this hazard class in accordance with the following table:

Table: Excerpt from HPR 7.17.1

	Column 1	Column 2
Item	Category	Criteria
1	Corrosive to Metals — Category 1	A mixture or substance that (a) has been shown to, upon ignition, catch fire or explode when dispersed in air; or (b) is classified in a category of the hazard class "Flammable Solids" and 5.0% or more of its composition by weight is a flammable solid and has a particle size ≤ 500 µm

Experience with use or storage of a substance or mixture may be used to classify it in the Combustible Dusts hazard class, if known. For example, if the supplier knows that a substance or mixture has been involved in a fire or dust explosion incident, the supplier must classify the substance or mixture in Combustible Dusts — Category 1. A substance or mixture which has been shown through testing to catch fire or explode upon ignition when dispersed in air or other oxidizing medium must also be classified in Combustible Dusts — Category 1.

When there is no physical evidence or test results, or if the testing is inconclusive, classification may be based on particle size, if particle size information is available. If the substance or mixture is classified in a category of the Flammable Solids hazard class and 5% or more of its composition by weight has a particle size 500 microns (µm) or less, then it must be classified in Combustible Dusts — Category 1.

Particle size is the average size of the solid particle. It can be measured by passing the solid through a series of standardized mesh sieves. If all of the solid was to pass through a particular sieve then the solid would be described as having a particle size less than or equal to the mesh size of the sieve. There are a number of ways sieve sizes are identified; some are by the size of the particles and others by the number of openings per linear inch (US Sieve Series and Tyler Mesh). For example, a substance or mixture that passes through a U.S. Sieve No. 35 would be considered to have a particle size ≤ 500 µm (OSHA Hazard Classification Guidance 2016, p. 383).

Physical properties

Particle size is an important property as it typically influences the ease of ignition and the severity of a combustible dust explosion. Other factors which influence the explosiveness of dusts include moisture content, ambient humidity, oxygen available for combustion, the shape of dust particles, and the concentration of dust in the air. Physical properties used to measure combustible dusts hazards include the following:

• Minimum ignition energy (MIE), which predicts the ease and likelihood of ignition of a dispersed dust cloud
• Minimum explosible concentration (MEC), which measures the minimum amount of dust dispersed in air required to spread an explosion. (The MEC is analogous to the Lower Flammable Limit (LFL) or Lower Explosive Limit (LEL) for gases and vapors in air)
• Dust deflagration index (K_st), which measures the relative explosion severity compared to other dusts. The severity of an explosion is expected to increase with the value for K_st (See Table 7.6). K_st provides the best "single number" estimate of the anticipated behavior of a dust deflagration

Table 7.6 Examples of K_st values for different types of dusts

Kst (bar.m/s)	General Characteristic	Typical Substances
0	No explosion	Silica
> 0 and ≤ 200	Weak explosion	Powdered milk, charcoal, sulfur, sugar and zinc
> 200 and ≤ 300	Strong explosion	Cellulose, wood flour, and poly methyl acrylate
> 300	Very strong explosion	Anthraquinone, aluminum, and magnesium
The actual Kst value is sample specific and will depend on varying characteristics of the substance or mixture such as particle size or moisture.

Note: Different dusts of the same substance or mixture can have different ignitability and explosibility characteristics, depending upon physical characteristics such as particle size, shape, and moisture content. Any combustible dust with a K_st value greater than zero can be subject to dust deflagration.

Published Test Results

Published literature is available and can be used to aid in classification. For example, the NFPA has published several standards, which include lists of test results for the combustible dust characteristics of various substances and materials.

There are also public databases of dust explosibility characteristics that may be consulted, such as the GESTIS-DUST-EX database maintained by the Institute for Occupational Safety and Health of the German Social Accident Insurance (Details of website: http://staubex.ifa.dguv.de/?lang=e), available in English, French, German and Dutch.

Testing

If published test results are not available and there is no experience demonstrating a combustible dust hazard, then laboratory testing could be conducted. Reliable test data for a substance or mixture, based on a scientifically validated method, is considered strong evidence for determining whether a substance or mixture presents a combustible dust hazard.

Reliable screening tests, such as the 1 described in ASTM E1226 (Standard Test Method for Explosibility of Dust Clouds), showing a positive normalized rate of pressure rise or dust deflagration index (K_st) may be used. The ASTM E1515 (Standard Test Method for Minimum Explosible Concentration of Combustible Dusts) method may also be used.

Hazard Communication

Part 1 of Schedule 5 of the HPR specifies the information elements required on labels and SDSs of products classified as Combustible Dusts. The signal word is "Warning" and there are 2 options for the hazard statement. Either "May form combustible dust concentrations in air" or "May form explosible dust-air mixture" may be used. A symbol is not required. As per subparagraph 3(1)(d)(ii) of the HPR, the supplier is required to include applicable precautionary statements.

Subpart 18 Simple Asphyxiants

Simple Asphyxiants is not a GHS hazard class.

Discussion

The Simple Asphyxiants hazard class is intended to capture any gas that displaces air and causes oxygen deprivation in those who are exposed, and may result in unconsciousness and death. The definition specifies that this hazard class applies to gases only, vapours are not included.

Simple asphyxiants are gases that are harmful to the body when they become very concentrated and reduce oxygen in the air to dangerous levels.

Classification in the Category of the Class

Discussion of section 7.18.1 of the Hazardous Products Regulations

Category

7.18.1 A simple asphyxiant is classified in the category of this hazard class in accordance with the following table:

Table: Excerpt from HPR 7.18.1

	Column 1	Column 2
Item	Category	Criteria
1	Simple Asphyxiants — Category 1	A gas that is a simple asphyxiant

A substance or mixture is classified in Simple Asphyxiants — Category 1 if it meets the definition of a simple asphyxiant.

Hazard Communication

Part 2 of Schedule 5 of the HPR specifies the information elements required on labels and SDSs of products classified as Simple Asphyxiants. The signal word is "Warning" and the hazard statement is "May displace oxygen and cause rapid suffocation". A symbol is not required. As per subparagraph 3(1)(d)(ii) of the HPR, the supplier is required to include applicable precautionary statements.

Examples

Examples of simple asphyxiants that should be considered for classification in Simple Asphyxiants — Category 1 include:

• the "inert" gases, as well as the "relatively inert" gases like the aliphatic alkanes and the chlorofluorocarbons
• hydrogen, helium, ethane, ethylene, nitrogen, neon; carbon dioxide, acetylene, argon, methane, propane, propylene

Subpart 19 Pyrophoric Gases

Subpart 20 Physical Hazards Not Otherwise Classified

Physical Hazards Not Otherwise Classified is not a GHS hazard class.

Discussion of section 7.20 of the Hazardous Products Regulations

The Physical Hazards Not Otherwise Classified (PHNOC) hazard class is intended to capture physical hazards which are not already covered by any of the other physical hazard classes addressed in Part 7 of the HPR. Therefore, this hazard class does not include effects that are considered under any of the existing physical hazard classes and that did not meet the criteria (for example, an organic peroxide that did not meet the requirements for classification into any of the Organic Peroxide hazard class categories (types)). In addition, PHNOC does not include physical hazards that fall into a GHS hazard category that has not been adopted in the HPR. At this time, for each physical hazard class that has been adopted from the GHS, all of its respective categories have been adopted.

The expression "the characteristic of occurring by chemical reaction" used in section 7.20 of the HPR in the context of injury or death means that the injury or death may occur as a secondary effect of the hazard, and that the hazard exists regardless of the exposure of a person to the product, mixture, material or substance.

Guidance for Health Hazards Not Otherwise Classified (HHNOC) is provided in Part 8 of this guidance which discusses Subpart 12 of Part 8 of the HPR. HHNOC require exposure to exert their effect. The expression HHNOC also excludes radiological hazards and electrical conductivity.

The expression "resulting in serious injury or death" excludes minor hazards; however, it includes incidents where only property damage occurs, but if a person is present, it would result in a serious injury or death.

Classification in the Category of the Class

Discussion of section 7.20.1 of the Hazardous Products Regulations

A product, mixture, material or substance is classified in PHNOC — Category 1 if it meets the definition of a physical hazard not otherwise classified.

Prescribed classification

As per subsection 2(3) of the HPR, there are several substances and mixtures listed as PHNOC — Category 1 in Schedule 4 of the HPR "Prescribed Classification". For further information, please refer to the discussion of subsections 2(3), 2(4), and 2(5) of the HPR.

Hazard Communication

Hazard communication requirements for PHNOC are provided in Part 4 of Schedule 5 of the HPR.

Any pictogram found in Schedule 3 of the HPR that is applicable to the hazard, the signal word "Danger" and hazard statement(s) appropriate to the hazard (that is, wording that describes the nature of the hazard) must be provided. Under item 2(a) of the SDS, the hazard classification or a description of the hazard identified is required. As per subparagraph 3(1)(d)(ii) of the HPR, suppliers are required to provide appropriate precautionary statements.

Examples

Example 7.20.1:

There is a substance with a UN number of 1310 that has not been mixed with other ingredients. UN number 1310 is prescribed a classification of PHNOC — Category 1 in Schedule 4 of the HPR "Prescribed Classification". The substance has not been mixed with 1 or more ingredients and is classified in the most severe category of the classification table of the hazard class. Therefore, as per subsection 2(3) of the HPR, this substance is classified as PHNOC — Category 1. Subsection 2(4) of the HPR is not triggered.

Example 7.20.2:

Vigorous polymerization is 1 example of a PHNOC. Polymerization is a chemical reaction in which many small molecules (monomers) join together to form a large molecule (polymer). Often the reaction produces heat and pressure. Industry carries out these processes under closely monitored conditions. Other chemicals (catalysts and initiators) and controlled amounts of heat, light and pressure are often involved. Vigorous polymerization is potentially hazardous because the reaction may get out of control. Once started, the reaction is accelerated by the heat that it produces. The uncontrolled build-up of heat and pressure can cause a fire or an explosion, or can rupture closed containers. Depending on the product, temperature increases, sunlight, ultraviolet (UV) radiation, X-rays or contact with incompatible chemicals can trigger such reactions.

Many substances (that is, uninhibited) can undergo vigorous polymerization quite easily by themselves when they are heated slightly or exposed to light. The following examples of substances should be considered for classification in PHNOC — Category 1 if they meet the criteria for this hazard class:

• acrylic acid
• acrylonitrile
• cyclopentadiene
• diketene
• ethyl acrylate
• hydrocyanic acid
• methacrylic acid
• methyl acrylate
• vinyl acetate

Subpart 21 Chemicals Under Pressure

Discussion – Chemicals Under Pressure

The GHS defines chemicals under pressure as "liquids or solids (e.g., pastes or powders), pressurized with a gas at a pressure of 200 kPa (gauge) or more at 20 °C in pressure receptacles other than aerosol dispensers and which are not classified as gases under pressure" (GHS eighth revised edition, 2019, section 2.3.2.1). The HPR also makes the distinction that chemicals under pressure excludes any gas under pressure as defined in section 7.5 of the HPR.

Classification in a Category of the Class

Discussion of subsection 7.21.1 of the Hazardous Products Regulations

If a product is classified in the Aerosols hazard class, it must not be classified in the Chemicals Under Pressure hazard class. The criteria for classification in the Aerosols hazard class is found in section 7.3.1 of the HPR.

Discussion of subsection 7.21.1(2) of the Hazardous Products Regulations

Chemicals under pressure are classified in either Category 1, Category 2 or Category 3 of the Chemicals Under Pressure hazard class depending on their content of flammable components and their heat of combustion.

The flammable components could be a substance or mixture that is classified in a category or subcategory of the following hazard classes:

• Flammable Gases (Subpart 2 of Part 7 of the HPR)
• Flammable Liquids (Subpart 6 of Part 7 of the HPR)
• Flammable Solids (Subpart 7 of Part 7 of the HPR)

Chemicals under pressure should be considered for classification in Category 1 or 2 of the Chemicals Under Pressure hazard class if they contain more than 1% components (by mass) which are classified as flammable.

The specific heats of combustion may be found in literature, calculated or determined by testing. For a composite formulation, the specific heat of combustion of the product is the summation of the weighted specific heats of combustion for the individual components, as follows:

where:

ΔH_c(product) = ∑ⁿ[w(i)xΔH_c(i)]

ΔH_c(product) = specific heat of combustion (kJ/g)

ΔH_c(i) = specific heat of combustion (kJ/g) of component i in the product

w(i) = mass fraction of component i in the product

n = total number of components in the product

(GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

The heats of combustion can be determined by the following tests methods or other scientifically validated methods:

• ASTM D240-19: Standard Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter;
• ISO 13943: 2017: Fire Safety - Vocabulary, Third Edition, July 2017, Sections 86.1 to 86.3; and
• NFPA 30B, Code for the Manufacture and Storage of Aerosol Products, 2023 Edition.

(GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

Note: Any product that is classified in a category of the hazard class Chemicals Under Pressure must not be classified in any category or subcategory of the following hazard classes:

• Flammable Gases (Subpart 2 of Part 7 of the HPR)
• Aerosols (Subpart 3 of Part 7 of the HPR)
• Gases Under Pressure (Subpart 5 of Part 7 of the HPR)
• Flammable Liquids (Subpart 6 of Part 7 of the HPR)
• Flammable Solids (Subpart 7 of Part 7 of the HPR)

Hazard Communication

The symbol, signal words as well as hazard and precautionary statements for Chemicals Under Pressure are provided in Section 3 of Annex 3 of the GHS, eighth revised edition, 2019, p. 324 (Category 1 and Category 2) and p. 325 (Category 3), with the exception of the Category 3 hazard statement. For hazardous products classified in the category Chemicals Under Pressure — Category 3, the hazard statement "Chemical under pressure: May explode if heated/Produit chimique sous pression : peut exploser sous l'effet de la chaleur" is required on the label and SDS, as specified in paragraph 3(1)(c.2), paragraph 4(1)(b), and Schedule 1 of the HPR.

Classification of Chemicals Under Pressure Example

(GHS, eighth revised edition, 2019, paragraph 2.3.3.1)

Example 7.21.1:

The following example explains the classification process for a product suspected of being a chemical under pressure when data on flammable components and on the heat of combustion are available.

Available data

The hypothetical product CUP1 is a chemical under pressure, containing a mixture of liquids pressurized with a gas in a receptacle that is not an aerosol dispenser. CUP1 is not considered as a gas under pressure as per Section 7.5 of the HPR. It is contained in a receptacle with a pressure higher than 200 kPa at 20 °C with:

• Flammable components: 75% (by mass) Liquid 1, 20% (by mass) Liquid 2
• Non-flammable components: 5%
• The specific heats of combustion (ΔH_c) for liquids in the mixture:
  • ΔH_c (Liquid 1) = 43.5 kJ/g
  • ΔH_c (Liquid 2) = 24.7 kJ/g
  • ΔH_c (other non-flammable components) = 0 kJ/g

Classification

The product CUP1 meets the criteria for Chemicals Under Pressure — Category 1.

Rationale

The specific heat of combustion (ΔH_c) of the product can be calculated using the formula presented below:

• ΔH_c (product) = ∑ⁿ[w(i)xΔH_c(i)]
• ΔH_c (CUP1) = [w(i) x ΔH_c(i) for Liquid 1] + [w(i) x ΔH_c(i) for Liquid 2] + [w(i) x ΔH_c(i) for the non-flammable components]
• ΔH_c (CUP1) = [0.75 x 43.5] + [0.20 x 24.7] + [0.05 x 0] = 32.63 + 4.94 + 0 = 37.57 kJ/g

The information gathered is then compared to the classification criteria:

1. Is CUP1 a mixture containing liquids or solids pressurized with a gas, in a receptacle other than an aerosol dispenser, which is not classified as a gas under pressure?

   Yes. It is a mixture of liquids pressurized with a gas in a receptacle that is not an aerosol dispenser and is not classified as a gas under pressure.

2. Is the mixture contained in a receptacle with a pressure of higher than 200 kPa at 20 °C?

   Yes. It is contained in a receptacle with a pressure higher than 200 kPa at 20 °C.

3. Does CUP1 contain ≥ 85% flammable components and does it have a heat of combustion ≥ 20 kJ/g?

   Yes. It has 95% flammable components and the heat of combustion is 37.6 kJ/g.

Therefore, product CUP1 is classified in Chemicals Under Pressure — Category 1.

Example 7.21.2:

The following example explains the classification process for a product suspected of being a chemical under pressure when data on flammable components and on the heat of combustion are available.

Available data

The hypothetical product CUP2 is a chemical under pressure, containing a mixture of liquids and pressurized with a gas in a receptacle that is not an aerosol dispenser. CUP2 is not considered as a gas under pressure as per Section 7.5 of the HPR. It is contained in a receptacle with a pressure higher than 200 kPa at 20 °C with:

• Flammable components: 4% (by mass) Liquid 1
• Non-flammable components: 96%
• The specific heats of combustion (ΔH_c) for liquids in the mixture:
  • ΔH_c (Liquid 1) = 43.5 kJ/g
  • ΔH_c (other non-flammable components) = 0 kJ/g

Classification

The product CUP2 meets the criteria for Chemicals Under Pressure — Category 2.

Rationale

The specific heat of combustion (ΔH_c) of the product can be calculated using the formula presented below:

• ΔH_c (product) = ∑ⁿ[w(i)xΔH_c(i)]
• ΔH_c (CUP2) = [w(i) x ΔH_c(i) for Liquid 1] + [w(i) x ΔH_c(i) for the non-flammable components]
• ΔH_c (CUP2) = [0.04 x 43.5] + [0.96 x 0] = 1.74 + 0 = 1.7 kJ/g

1. Is CUP2 a mixture containing liquids or solids pressurized with a gas, in a receptacle other than an aerosol dispenser, which is not classified as a gas under pressure?

   Yes. It is a mixture of liquids pressurized with a gas in a receptacle that is not an aerosol dispenser and is not classified as a gas under pressure.

2. Is the mixture contained in a receptacle with a pressure of higher than 200 kPa at 20 °C?

   Yes. It is contained in a receptacle with a pressure higher than 200 kPa at 20 °C.

3. Does CUP2 contain ≥ 85% flammable components and does it have a heat of combustion ≥ 20 kJ/g?

   No. It has 4% flammable components and the heat of combustion is 1.7 kJ/g.

4. Does CUP2 contain >1% flammable components and a heat of combustion <20 kJ/g or contain <85% flammable components and a heat of combustion ≥ 20 kJ/g?

   Yes. It has 4% flammable components and the heat of combustion is 1.7 kJ/g.

Therefore, product CUP2 is classified in the Chemicals Under Pressure — Category 2.

References for this section of the guide (Hazardous Products Regulations — Part 7 Physical Hazard Classes)

• ECHA Guidance on the Application of the CLP Criteria, Guidance to Regulation (EC) No 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, Version 5.0, July 2017
• Fire Protection Guide to Hazardous Materials, 13^th Edition, 2002, NFPA 325
• Hazardous Products Act, R.S.C., 1985, c.H-3
• Hazardous Products Regulations, SOR/2015-17
• OSHA Hazard Classification Guidance for Manufacturers, Importers, and Employers, 2016
• UN Globally Harmonised System of Classification and Labelling of Chemicals (GHS), seventh revised edition, 2017
• UN Globally Harmonised System of Classification and Labelling of Chemicals (GHS), eighth revised edition, 2019
• UN Manual of Tests and Criteria, seventh revised edition, 2019
• UN Recommendations on the Transport of Dangerous Goods, Model Regulations, 22nd revised edition, 2021
• U.S. Department of Transport - Dangerous Goods Regulations

Part 8 Health Hazard Classes

Introduction

This Part provides guidance to assist suppliers in determining the appropriate hazard classification of a substance, material or mixture in relation to the health hazard classes set out in Part 8 of the Hazardous Products Regulations (HPR). Health effects can either be acute (for example, Acute Toxicity, Specific Target Organ Toxicity — Single Exposure) or chronic (for example, Carcinogenicity, Reproductive Toxicity). Classification in relation to the health hazard classes is based on existing data and no additional testing is required to be undertaken. All available data must be evaluated against the criteria for each health hazard class to determine the health hazard classification of a substance, material or mixture.

The list of Health Hazard classes in Schedule 2 of the Hazardous Products Act (HPA) is the following:

1. Acute Toxicity
2. Skin Corrosion/Irritation
3. Serious Eye Damage/Eye Irritation
4. Respiratory or Skin Sensitization
5. Germ Cell Mutagenicity
6. Carcinogenicity
7. Reproductive Toxicity
8. Specific Target Organ Toxicity — Single Exposure (STOT-SE)
9. Specific Target Organ Toxicity — Repeated Exposure (STOT-RE)
10. Aspiration Hazard
11. Biohazardous Infectious Materials (BIM)^{Footnote 1}
12. Health Hazards Not Otherwise Classified (HHNOC)^{Footnote 1}

Types of data that can be used to classify a substance, material or mixture in the health hazard classes

When classifying a substance or material with respect to the health hazard classes set out in Part 8 of the HPR, certain types of data are to be used, as specified in subparagraphs 2.1(a)(i) to (iv) and 2.1(b)(i) to (iv) of the HPR.

Data on the substance or material may include any of the following:

• results of testing or studies carried out in accordance with the test methods referred to in Part 8
• results of testing or studies carried out in accordance with generally accepted standards of good scientific practice at the time the test or study was carried out
• conclusions based on established scientific principles and
• case reports or documented observations

If data on the substance or material itself are unavailable or are insufficient to evaluate the substance or material in accordance with the applicable criteria, then, for each health hazard class except for Subparts 2 and 3 of Part 8 (Skin Corrosion/Irritation and Serious Eye Damage/ Eye Irritation, respectively), data of the types listed above for a substance or material with similar properties to the substance or material that is being classified must be considered.

Skin Corrosion/Irritation and Serious Eye Damage/Eye Irritation are excluded because these hazard classes provide a sequential approach to the determination of classification that already incorporates the consideration of different types of data, beginning with data on the substance itself and then other types of data, such as pH, followed by data on similar substances.

Further guidance is provided in the discussion of section 2.1 of the HPR.

When classifying a mixture with respect to the health hazard classes set out in Part 8 of the HPR, the types of data to be used are the same as those listed above. The data may pertain to the ingredients of the mixture, the mixture as a whole or a mixture with similar properties, as specified in subsection 2.2(2) of the HPR. Further guidance is provided in the discussion of subsection 2.2(2) of the HPR.

Considerations that are relevant to the health hazard classification of a substance, material or mixture

The following considerations may apply to the classification of a substance, material or mixture in any health hazard class. There is no specific reference to these provisions within the respective Subparts of Part 8; however, they must always be considered as part of the classification process.

Animal data – not relevant to humans

Subsection 2(9) of the HPR specifies that animal data from a particular species of animal for which it has been conclusively demonstrated, based on established scientific principles, that the mechanism or mode of action of the substance or mixture in that particular species of animal is not relevant to humans must not be used for the purpose of classifying a substance or mixture in any of the health hazard classes referred to in Subparts 1 to 10 and 12 of Part 8. This provision does not apply to Subpart 11 of Part 8 (BIM). Further guidance is provided in the discussion of subsection 2(9) of the HPR.

Biological availability

Section 2.9 of the HPR specifies that a substance, material or mixture need not be classified in any health hazard class if it can be shown by conclusive experimental data from scientifically validated methods that the substance, material or mixture is not biologically available. Further guidance is provided in the discussion of section 2.9 in Part 2 of this guidance.

Classification of mixtures in the health hazard classes: order of provisions

When classifying a mixture with respect to the health hazard classes, a "tiered" approach must be followed. This means that the order of provisions for the classification of mixtures, as set out in each health hazard class, must be followed (as specified in subsection 2.2(2) of the HPR). This procedure will generally (but not always) require the following sequential steps:

1. Where test data are available for the mixture as a whole, the classification of the mixture will be based on that data.
2. Where test data are not available for the mixture as a whole, then the applicable bridging principles, as set out in subsections 2.3(3) to 2.3(8) of the HPR, must be used. In order to apply the bridging principles, sufficient test data must be available for similar mixtures and for individual ingredients of the mixture to be classified.
3. If test data are not available for the mixture as a whole, and sufficient data to allow the application of bridging principles are also not available, then the method(s) described in each Subpart for determining the hazards based on the ingredients of the mixture must be applied to classify the mixture (for example, application of cut-off values/concentration limits/calculation methods).

In the case of Subparts 5, 6 and 7 of Part 8 (Germ Cell Mutagenicity, Carcinogenicity and Reproductive Toxicity, respectively), the order of provisions is different from the above. The first step in the classification of mixtures is the evaluation of available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified as germ cell mutagens, carcinogens, or reproductive toxicants, respectively. However, if there are test data for the mixture as a whole, these data may be used to classify the mixture, instead of data on the individual ingredients. As a final step, applicable bridging principles may be used to classify the mixture.

For Subpart 11 of Part 8 (BIM), the classification of mixtures follows the same procedure as for the classification of substances. Bridging principles do not apply to this hazard class.

For Subpart 12 of Part 8 (HHNOC), the first step in the classification of mixtures is the evaluation of available test data for the mixture as a whole. Where test data are not available for the mixture as a whole, then classification is based on available test data for the individual ingredients of the mixture using a concentration cut-off value for the ingredients classified as HHNOC. Bridging principles do not apply to this hazard class.

Further guidance is provided in the discussion of subsection 2.2(2) of the HPR and in the discussions of each Subpart of Part 8 of the HPR.

Classification of mixtures in the health hazard classes: in general, classification stops at the first provision that permits the classification of a mixture

As specified in subsection 2.2(3) of the HPR, except in the case of Subparts 1, 4, 7 and 8 of Part 8 (Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity and STOT-SE, respectively), the first provision that results in a mixture being classified in a category or subcategory of a health hazard class concludes the process of classification with regard to that particular health hazard class. No further evaluation of the mixture in relation to the remaining provisions for the classification of mixtures in that health hazard class is necessary.

Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity and STOT-SE are different because, for these health hazard classes, it is possible for a mixture to be classified in more than 1 category. These health hazard classes contain more than 1 classification table and it is necessary to evaluate the data for a mixture against the criteria in each classification table. For example, in Subpart 7 of Part 8 (Reproductive Toxicity), it is possible for a mixture to be classified in:

• Reproductive Toxicity — Category 1
• Reproductive Toxicity — Category 2
• Reproductive Toxicity — Effects on or via Lactation
• both Reproductive Toxicity — Category 1 and Reproductive Toxicity — Effects on or via Lactation or
• both Reproductive Toxicity — Category 2 and Reproductive Toxicity — Effects on or via Lactation

Further guidance is provided in the discussion of subsection 2.2(3) of the HPR and in the discussions of each Subpart of Part 8 of the HPR.

Classification of mixtures in the health hazard classes: bridging principles

Guidance and a summary table on the application of the bridging principles to the health hazard classes of the HPR is provided in the discussion of subsections 2.3(1) to 2.3(8) in Part 2 of this guidance.

Considerations that are relevant to the classification of a mixture in the health hazard classes when classification is based on ingredient data

The following considerations may apply to the classification of a mixture in any health hazard class, unless otherwise specified, when classification is based on the evaluation of available test data for the individual ingredients of the mixture. There is no specific reference to these provisions within the respective Subparts of Part 8; however, they must always be considered as part of the classification process.

Synergistic Effects (subsection 2.4(1) of the HPR)

All data available on the potential occurrence of synergistic effects among the ingredients of the mixture must be used in the evaluation.

Antagonistic Effects (subsection 2.4(2) of the HPR)

If data that show antagonistic effects among the ingredients of the mixture are used, this data must be conclusive and must be based on established scientific principles. Otherwise, data showing antagonistic effects must not be used for the purpose of classifying the mixture.

Concentration Limits — Lower Concentration (subsection 2.5(1) of the HPR)

When classifying a mixture in a particular category or subcategory of any health hazard class except for Subpart 11 of Part 8 (BIM), based on data available for the ingredients of the mixture, if there are data showing that an ingredient still presents the hazard at a concentration which is lower than the applicable concentration limit (cut-off value), then the mixture must be classified in that category or subcategory of that hazard class. This provision takes precedence over the concentration limit rule.

Concentration Limits — Equivalent or Higher Concentration (subsection 2.5(2) of the HPR)

When classifying a mixture in a particular category or subcategory of any health hazard class except for Subpart 11 of Part 8 (BIM), based on data available for the ingredients of the mixture, this provision may be applied if there is appropriate supporting evidence. The provision specifies that, if an ingredient is present in a mixture at a concentration that is equal to or higher than the concentration limit for a particular category or subcategory of a health hazard class, but there are scientifically valid data showing that, based on established scientific principles, the ingredient does not present the hazard at that concentration, then the mixture need not be classified in that category or subcategory of that hazard class due to the presence of that specific ingredient.

It is important to note that synergistic effects between the ingredients in a mixture must be taken into account before concluding that an ingredient, which is present in a mixture at a concentration that is equal to or higher than the concentration limit for a particular category or subcategory of a health hazard class, does not present the associated hazard. Therefore, the supplier must refer to the requirement specified in subsection 2.4(1) of the HPR. If there are test data that specifically relate to the mixture that is being evaluated, then any synergistic effects between the ingredients present in the mixture will already have been reflected in the test results for the mixture.

Maximum Concentration (section 2.6 of the HPR)

If a mixture contains a hazardous ingredient that is not always present at the same concentration, the maximum concentration at which the ingredient could be present in the mixture must be used for the purposes of establishing whether the mixture is classified in a category or subcategory of any health hazard class.

This provision is intended to ensure that the most conservative approach is taken when classifying a mixture that contains ingredients that could be present at varying concentrations.

Further guidance with regard to these provisions is provided in the discussion of the relevant section or subsection in Part 2 of this guidance.

Classification Examples

Classification examples are provided at the end of each Subpart of Part 8 of this guidance document. The United Nations Sub-Committee of Experts on the GHS has also developed several classification examples and posted them as guidance under Section 1: Examples on the application of GHS criteria on their Guidance on the application of GHS criteria webpage.

Technical Decision Trees

To support suppliers in classifying the health hazards of hazardous products to be used in Canadian workplaces, Health Canada and the Canadian Centre for Occupational Health and Safety have developed technical decision trees. These decision trees visually depict the sequential logic flow of the classification process for different health hazard classes. While these cover key classification requirements identified in each Subpart of Part 8 of the HPR, they are not exhaustive of all classification requirements of the HPR.

Acronyms referred to in Part 8 – Health Hazards include the following:

CLP

Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures

ECHA

European Chemicals Agency

GHS

Globally Harmonised System of Classification and Labelling of Chemicals, seventh revised edition, 2017

HPA

Hazardous Product Act

HPR

Hazardous Product Regulations

OECD

Organization for Economic Cooperation and Development

TG

Test Guideline

Subpart 1 Acute Toxicity

Discussion – Acute Toxicity

Acute toxicity refers to adverse effects occurring following oral or dermal administration of a single dose of a substance or mixture, or multiple doses given within 24 hours, or an inhalation exposure to a substance or mixture of 4 hours or of a duration that is converted to 4 hours.

For the Acute Toxicity hazard class, classification of a substance or mixture must be considered for each applicable route of exposure (oral, dermal and inhalation), and it is possible for a substance or mixture to be classified in a different category for each relevant route of exposure (that is, in more than 1 category at once). For example, a substance could be classified in Acute Toxicity (Oral) — Category 1, Acute Toxicity (Dermal) — Category 2, and Acute Toxicity (Inhalation) — Category 4, if the substance meets the criteria to be classified in each of these categories. Further guidance is provided in the discussion of subsection 8.1.1(1) of the HPR.

Discussion of section 8.1 of the Hazardous Products Regulations

In addition to the terms defined in section 8.1 of the HPR, the following terms, which are used in this Subpart, are defined in subsection 1(1) of the HPR.

• ATE: an acute toxicity estimate, and includes the LD₅₀ and the LC₅₀, and the acute toxicity point estimate determined in accordance with the table to section 8.1.7
• LC₅₀: the concentration of a mixture or substance in air that causes the death of 50.0% of a group of test animals
• LD₅₀: the concentration of a mixture or substance in air that causes the death of 50.0% of a group of test animals
• Gas: a mixture or substance that
  1. (a) at 50°C has an absolute vapour pressure of greater than 300 kPa; or
  2. (b) is completely gaseous at 20°C and at the standard pressure of 101.3 kPa
• Vapour: the gaseous form of a mixture or substance released from its liquid or solid state

Discussion related to these terms is found in Part 1 of this guidance.

Discussion – Dust and Mist

Dust is generally formed through mechanical processes whereas mist is generally formed through condensation of supersaturated vapours or by physical shearing of liquids. Dusts and mists generally have sizes ranging from less than 1 to about 100 μm (GHS, seventh revised edition, 2017, note (e) to Table 3.1.1).

Discussion – Acute Toxicity Point Estimate

The 2 terms "acute toxicity estimate" (ATE) and "acute toxicity point estimate" (ATPE) do not have the same meaning under the HPR. The term "acute toxicity estimate" could apply to:

1. a hazardous product that is a substance
2. a hazardous product that is a mixture or
3. an ingredient in a hazardous product that is a mixture.

The ATE could include any of the following:

• an LD₅₀ value
• an LC₅₀ value
• an ATPE or
• a calculated value, for a mixture, that is determined using the mathematical formula in section 8.1.5 or 8.1.6 of the HPR

The term ATPE is not defined under the HPR. However, an ATPE is a numerical value that is often determined if a formula in section 8.1.5 or 8.1.6 is used, in accordance with the table to section 8.1.7 of the HPR. The ATPE serves as an indicator of acute toxicity, that is, it is a conservative approximation of the lethal dose (LD₅₀) or lethal concentration (LC₅₀), of a substance or an ingredient in a mixture. The ATPE must be established when the supplier does not know the LD₅₀ or LC₅₀ value of the ingredient, but knows either:

1. the experimentally obtained acute toxicity range within which the LC₅₀ or LD₅₀ value for the substance or ingredient falls, or
2. the acute toxicity hazard category into which the substance or ingredient falls

Where there is no specific LD₅₀ or LC₅₀ value available for an ingredient in a mixture, determining the ATPE allows an acute toxicity value (that is, the ATPE value) for this ingredient to be used in the calculation of the ATE of the mixture, according to section 8.1.5 or 8.1.6 of the HPR. The ATPE is also determined for a product that is a substance where an exact LD₅₀ or LC₅₀ is unavailable.

Note: As with LC₅₀ and LD₅₀ values, the lower the ATPE value, the more hazardous the ingredient.

Discussion – Test Species

The preferred test species for evaluation of acute toxicity by the oral and inhalation routes is the rat, while the rat or rabbit are preferred for evaluation of acute dermal toxicity (GHS, seventh revised edition, 2017, paragraph 3.1.2.3). When experimental data for acute toxicity are available in several animal species, the most appropriate LD₅₀ or LC₅₀ value must be selected from among scientifically validated tests.

Although preferred species are mentioned here, it does not mean that these species take precedence over other species. Available data of the types referred to in paragraph 2.1(a) or (b) of the HPR pertaining to species other than the preferred test species mentioned above are also acceptable, provided that the mixture or substance can be concluded as being acutely toxic from the available data. For example, if there is dermal toxicity data from a well-conducted study in rat and mouse, and the mouse LD₅₀ value is lower than the rat LD₅₀ value, it is appropriate to use the mouse LD₅₀ value, despite the rat being the preferred species.

Classification in a Category of the Class

Classification of Substances

Discussion of subsection 8.1.1(1) of the Hazardous Products Regulations

An acute toxicity classification is assigned on the basis of evident lethality (for example, an LD₅₀ or LC₅₀ value) or where potential to cause lethality can be concluded from evident toxicity (for example, from a test performed according to OECD Test Guideline (TG) No. 420: Acute Oral Toxicity – Fixed Dose Procedure) (ECHA Guidance, 2017, paragraph 3.1.1).

The Acute Toxicity hazard class is unique because classification in this hazard class must be considered for each applicable route of exposure, as follows:

• Acute Toxicity (Oral)
• Acute Toxicity (Dermal)
• Acute Toxicity (Inhalation)

This requirement means that a substance could be classified in more than 1 acute toxicity hazard category by the applicable route of exposure. For example, a substance could be classified in each of Acute Toxicity (Oral) — Category 1, Acute Toxicity (Dermal) — Category 2, and Acute Toxicity (Inhalation) — Category 4.

Available data of the type referred to in paragraph 2.1 (a) or (b) of the HPR is used to classify substances in this hazard class. Subsection 8.1.1(1) refers to LD₅₀ (oral or dermal) or LC₅₀ (inhalation) values. If an LD₅₀ or LC₅₀ value is available, a substance must be classified in the appropriate category of this health hazard class by referring to the criteria set out in the 3 tables to subsection 8.1.1(3). These tables provide the ranges of LD₅₀ and LC₅₀ values and acute toxicity point estimates that correspond to classification in Acute Toxicity (Oral), Categories 1 through 4, Acute Toxicity (Dermal), Categories 1 through 4, and Acute Toxicity (Inhalation), Categories 1 through 4.

Acute Toxicity (Oral, Dermal, Inhalation) Category 5 from the GHS (seventh revised edition) was not adopted in the HPR.

Discussion of subsection 8.1.1(2) of the Hazardous Products Regulations

Subsection 8.1.1(2) of the HPR provides requirements with respect to substances that release toxic gas(es) upon contact with water at ambient temperature (that is, substances that present a water-activated toxicity hazard). These substances, when dry, do not emit gases with toxic properties, but can react vigorously with water to produce gases which can be harmful, toxic or fatal at low airborne concentrations. Subsection 8.1.1(2) of the HPR requires that the LC₅₀ value of the emitted gaseous substance be taken into consideration in the classification process if the substance emitting the gaseous substance is not already classified with respect to the inhalation route of exposure in a category of this hazard class. The LC₅₀ value of the emitted gaseous substance may be different from that of the emitting substance.

In addition, paragraph 3(1)(f) of the HPR prescribes supplemental information elements for water activated toxicants (substances and mixtures that, upon contact with water, release a gaseous substance that falls into 1 of the ranges indicated in Table 3 to subsection 8.1.1(3)). The supplemental hazard statements required are based solely on the category into which the emitted gaseous substance falls, and are required even if the emitted gaseous substance did not trigger a classification under subsection 8.1.1(2) of the HPR. The supplemental hazard statements are as follows:

For Categories 1 and 2, "In contact with water, releases gases which are fatal if inhaled/Au contact de l'eau, libère des gaz mortels en cas d'inhalation", for Category 3, "In contact with water, releases gases which are toxic if inhaled/Au contact de l'eau, libère des gaz toxiques en cas d'inhalation", and for Category 4, "In contact with water, releases gases which are harmful if inhaled/Au contact de l'eau, libère des gaz nocifs en cas d'inhalation".

For example, consider a substance that is classified in Acute Toxicity (Inhalation) — Category 1 and which, upon contact with water, emits a gaseous substance that has an LC₅₀/4 hours of 650 ppmV. The emitted gaseous substance, therefore, has an LC₅₀ that falls into the Acute Toxicity (Inhalation) — Category 3 range based on the criteria set out in Table 3 to subsection 8.1.1(3) of the HPR. In this example, the substance is classified in Acute Toxicity (Inhalation) — Category 1 and the emitted gaseous substance is not considered further for the classification of the substance. However, the supplemental information element for the emitted gaseous substance as mentioned in paragraph 3(1)(f) of the HPR for Category 3 is required on the label and safety data sheet (SDS).

The hazard statements required in this example are the following:

• Fatal if inhaled
• In contact with water, releases gases which are toxic if inhaled

Discussion of subsection 8.1.1(3) of the Hazardous Products Regulations

Tables 1, 2 and 3 to subsection 8.1.1(3) of the HPR provide the numeric cut-off criteria for classifying a substance in the acute toxicity hazard categories for each route of exposure based on LD₅₀, LC₅₀ or ATPE values.

Values for vapours, dusts and mists are expressed in milligrams/ litre (mg/l). Values for gases are expressed in parts per million by volume (ppmV). The formula for converting mg/l to ppmV is:

Figure 25 - Text description

A formula showing how to convert milligrams/litre (mg/l) to parts per million by volume (ppmV)

The formula for converting milligrams/litre to parts per million by volume consists of the following variables:

mg per l equals the values for vapours, dusts, and mists expressed in milligrams per litre,

ppmV equals the values for gases expressed in parts per million by volume,

MW is the molecular weight, and

24,450 is a constant value in the formula

The formula to convert milligrams/litre to parts per million by volume reads as follows:

mg per l equals the product of ppmV and the MW over 24,450

where MW is molecular weight.

When an exact LD₅₀ or LC₅₀ value is not available for the substance itself or for a substance with similar properties, subsection 8.1.1(3) specifies that an ATPE must be established according to the table to section 8.1.7 of the HPR. The table to section 8.1.7 of the HPR provides a single value. To establish an ATPE, information about the acute toxicity hazard category in which the substance is classified (for example, based on information obtained from an upstream supplier) or the range of values within which the LC₅₀ or LD₅₀ falls is required.

Using the ATPE or the exact LC₅₀ or LD₅₀ value, the substance is then classified for each applicable route of exposure using the criteria in the tables to subsection 8.1.1(3). For example, the available data for substance X is an LD₅₀ (oral) range of 60 to 85 mg/kg bw. Using the table to section 8.1.7, the ATPE for this substance is 100 mg/kg bw because 60-85 mg/kg falls within the range of 50 ≤ 300 mg/kg bw, which converts to an ATPE of 100 mg/kg bw. Since the ATPE is between 50 and 300 mg/kg bw, the substance is classified in Acute Toxicity (Oral) — Category 3.

Discussion of subsection 8.1.1(4) of the Hazardous Products Regulations

LC₅₀ values are based on a 4-hour exposure period. Where an LC₅₀ is obtained in an animal assay using an exposure duration other than 4 hours, the LC₅₀ can be converted to a 4-hour exposure duration equivalent by using the following formulae:

1. for a gas or vapour, LC₅₀ at 4 hours = LC₅₀ at Y hours x (Y hours)^1/2/2
2. for dust, mist or fume, LC₅₀ at 4 hours = LC₅₀ at Y hours x (Y hours)/4

Note: Y = actual number of hours of exposure duration, with maximum number of hours of exposure being 24 hours. Data with exposure period above 24 hours should not be used because above this threshold it will no longer be considered as an acute exposure.

These formulae assume a simple linear relationship between duration of exposure and concentration of dust, mist or fume in the animal chamber and a "square root" function for gas and vapour. The conversions provided in subsection 8.1.1(4) of the HPR are based on the above formulae, but can only be used to convert from 1-hour to 4-hour exposures.

Example 8.1.1:

If the LC₅₀ for a substance (gas) based on 1-hour exposure is 250 ppmV, then:

LC₅₀ at 4 hours = 250 ppmV/2 = 125 ppmV

Therefore, the substance is classified in Acute Toxicity (Inhalation) — Category 2.

If the LC₅₀ for a substance (gas) based on 10 hours exposure is 575 ppmV, then:

LC₅₀ at 4 hours = 575 × Ö10/2 = 909 ppmV

Therefore, the substance is classified in Acute Toxicity (Inhalation) — Category 3.

Classification in a Category in the Class

Classification of Mixtures

Discussion of subsections 8.1.2(1) and (2) of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for acute toxicity, meaning that the procedures described in sections 8.1.3 to 8.1.6 must be followed in the order in which these sections appear in the HPR.

Classification of mixtures for acute toxicity is dependent on the amount of information available for the mixture itself and for its ingredients. In the tiered approach, test data available on the complete mixture (that is, the mixture as a whole) is considered as the first tier in the evaluation, followed by the applicable bridging principles, and lastly, additivity formula based on the hazard information on ingredients (Figure 1).

Figure 26 - Text description

This is a flow chart that illustrates the tiered approach to the classification of mixtures for acute toxicity. The first step is a question about whether there are test data on the mixture as a whole. If yes, then the supplier must classify the mixture accordingly.

If no, are there sufficient data available on similar mixtures to estimate classification hazards? If yes, the supplier must apply bridging principles and classify the mixture accordingly.

If no, are there data available for all ingredients? If yes, the supplier must apply the formula and classify the mixture accordingly.

If no, are there other data available to estimate conversion values for classification? If yes, the supplier must apply the formula and classify the mixture accordingly.

If no, the last step is to convey the hazards of the known ingredients. The supplier must apply the formula (unknown ingredients less than or equal to 10%) or apply the formula (unknown ingredients greater than 10%) and classify the mixture accordingly.

In situations where a mixture is classified according to the calculations specified in section 8.1.5 and 8.1.6, subsection 8.1.2(2) of the HPR specifies which ingredients in the mixture must be taken into consideration. In general, only ingredients which are present at concentrations ≥ 1.0% (weight/weight for solids, liquids, dusts, mists and vapours and volume/volume for gases) need to be included in the calculation of an ATE of a mixture. However, as described in subsection 2.5(1) of the HPR, where an ingredient is present in a mixture at a lower concentration than the concentration cut-off for a particular category or subcategory of a health hazard class, but still presents the hazard at that concentration, the mixture must be classified in that category or subcategory. In the case of the Acute Toxicity hazard class, the provision described in subsection 2.5(1) would apply to situations where an ingredient is present in a mixture at a concentration of less than 1.0%, but the ingredient still presents an acute toxicity hazard at that concentration. In such situations, the ingredient must be included in the calculations specified in sections 8.1.5 and 8.1.6.

This "relevant ingredient" approach is aligned with the GHS. Paragraph 3.1.3.3 of the GHS states that the "relevant ingredients" of a mixture are those which are present in concentrations ≥ 1% (weight/weight for solids, liquids, dusts, mists and vapours and volume/volume for gases). If there is reason to suspect that an ingredient present at a concentration < 1% will affect classification of the mixture for acute toxicity, that ingredient shall also be considered relevant. Consideration of ingredients present at a concentration < 1% is particularly important when classifying untested mixtures which contain ingredients that are classified in Category 1 and Category 2 (GHS, seventh revised edition, 2017, paragraph 3.1.3.3(a)).

Discussion of section 8.1.3 of the Hazardous Products Regulations

As the first step in the tiered approach, if data of the types referred to in subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is exactly the same as for substances, and is carried out in accordance with section 8.1.1. Guidance for subparagraphs 2.1(a)(i) to (iv) of the HPR is found in section 2.1 of Part 2 of this guidance. The discussion sections of the guidance corresponding to subsections 8.1.1(1) through 8.1.1(4) of the HPR, as well as the classification of substances in general (Part 2 of the guidance), are relevant to the classification of mixtures if there is data available for the mixture as a whole. The data available on the mixture as a whole must be compared to the classification criteria within each hazard category for each relevant route of exposure. If the available data meets the criteria, then the mixture must be classified in the category(ies) for which the criteria are met.

Discussion of section 8.1.4 of the Hazardous Products Regulations

Section 8.1.4 of the HPR describes the second step in the tiered approach for the classification of mixtures for acute toxicity.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance. All of the bridging principles are applicable to the Acute Toxicity hazard class, namely: dilution, production batches, increase in concentration of hazardous ingredient, interpolation, substantially similar mixtures, and aerosols.

Discussion of section 8.1.5 and 8.1.6 of the Hazardous Products Regulations

When there is no data for the mixture as a whole and the bridging principles cannot be applied, then classification of the mixture must be based on information for the ingredients in the mixture using additivity formulas. There are 2 different additivity formulas set out in sections 8.1.5 and 8.1.6 of the HPR, which allow for the calculation of the ATE of the mixture.

Considerations

There are some important concepts to consider when applying the additivity formulas:

1. If an LD₅₀ (oral or dermal) or an LC₅₀ (inhalation) is available for an ingredient, it must be used in the calculation.
2. If an LD₅₀ (oral or dermal) or LC₅₀ (inhalation) value is not available for an ingredient in a mixture and an LD₅₀ or LC₅₀ range or the ingredient's acute toxicity classification is available, then an ATPE must be determined for the ingredient in accordance with the table to section 8.1.7 of the HPR. This ATPE is then used in the applicable formula.
3. If an ATPE cannot be determined for the ingredient, but there are data available that permit an ATE to be estimated in accordance with established scientific principles, then the ATE for the ingredient may be estimated accordingly. Determination of the ATE may include evaluation of:
   1. extrapolation between oral, dermal and inhalation acute toxicity values. When mixtures contain ingredients that do not have acute toxicity data for each route of exposure, acute toxicity estimates may be extrapolated from the available data and applied to the appropriate routes. Such an evaluation would require appropriate pharmacodynamic and pharmacokinetic data;
   2. evidence from human exposure that indicates toxic effects but does not provide lethal dose data. For example, methanol, where toxicity in humans is known but the animal LD₅₀/LC₅₀ values are greater than the cut-off values in the table to section 8.1.7 of the HPR;
   3. evidence from any other toxicity tests/assays available on the ingredient that indicates toxic acute effects but does not necessarily provide lethal dose data; or
   4. data from closely analogous substances using structure-activity relationships.

   This approach generally requires substantial supplemental technical information to reliably estimate acute toxicity (GHS, seventh revised edition, 2017, paragraph 3.1.3.6.2.1). If an ATE for the ingredient can be determined, it is then used in the applicable formula.

4. The additivity formula calculations must be done for each relevant route of exposure (oral, dermal and inhalation), as appropriate. The results of each calculation must be compared to the criteria in the 3 tables to subsection 8.1.1(3) of the HPR, to determine the classification.
5. For acute inhalation toxicity of a product that is a mixture, the calculation must be conducted separately for each relevant physical form (that is, gas, vapour, and/or dust/mist) if there are sufficient data available. The results of each calculation must be compared to the corresponding criteria to subsection 8.1.1(3) to determine the classification. In case of different outcomes, the most severe classification applies. Only relevant ingredients are included in the calculations. To determine which ingredients in a mixture are "relevant" to include in the calculation of the ATE of the mixture, consider the following:
   1. As specified in subsection 8.1.2(2), with some exceptions, only ingredients which are present at concentrations equal to or greater than 1.0% (weight/weight for solids, liquids, vapours, dusts and mists and volume/volume for gases) need to be included in the calculation of an ATE of a mixture;
   2. Ingredients with an ATE that falls within any of the ranges set out in Table 1, 2 or 3 to subsection 8.1.1(3) of the HPR (that is, ingredients that classify into Acute Toxicity Category 1, 2, 3 or 4 for the route of exposure for which the calculation is being done) must be included;
   3. Ingredients with an oral or dermal LD₅₀ greater than 2000 mg/kg bw but less than or equal to 5000 mg/kg bw (that is, ingredients that classify into GHS Acute Toxicity (Oral or Dermal) — Category 5) must be included in the oral and dermal calculations*.
   4. Ingredients with an LC₅₀ based on or converted to a 4-hour exposure period within a range comparable to an oral or dermal LD₅₀ greater than 2000 mg/kg bw but less than or equal to 5000 mg/kg bw (that is, ingredients that are classified in GHS Acute Toxicity (Inhalation) — Category 5) must be included* (GHS, seventh revised edition, 2017, paragraph 3.1.3.6.1(a)).
   5. Ingredients that are presumed not acutely toxic (for example, water, sugar) should not be included. Note that ingredients that are not biologically available could be also considered as "presumed not acutely toxic". Guidance pertaining to biological availability is found in the discussion of section 2.9 of the HPR in Part 2 of this guidance; and
   6. Ingredients for which data are available from a limit dose test at the upper threshold for Category 4 for the appropriate route of exposure as provided in Table 1, 2 or 3 of subsection 8.1.1(3), and the data do not show acute toxicity should not be included.

   * Ingredients which fall within GHS Acute Toxicity (Oral, Dermal or Inhalation) — Category 5 should only be included in mixture calculations when actual toxicity data (that is, an LD₅₀ or LC₅₀ value) is available, and not when there is only a Category 5 classification available.

6. Where a classified mixture is used as an ingredient of another mixture, the actual or calculated ATE for the already classified mixture must be used when determining the classification of the new mixture (GHS, seventh revised edition, 2017, paragraph 3.1.3.3(b)) using either the formula in section 8.1.5 or the formula in section 8.1.6, as applicable.

The formula set out in section 8.1.5 is used in the following 2 situations:

1. when there are data available for all relevant ingredients in the mixture; and
2. when there are no data available for 1 or more relevant ingredients and the total concentration of the relevant ingredient(s) with unknown acute toxicity is less than or equal to 10.0%

The formula set out in section 8.1.6 is used when data are not available for 1 or more ingredients and the total concentration of the relevant ingredient(s) with unknown acute toxicity is greater than 10.0%. This formula incorporates a correction to adjust for the percentage of the unknown ingredient(s).

Note that, with regard to the classification of mixtures for the inhalation route of exposure, the formulas set out in sections 8.1.5 and 8.1.6 of the HPR are intended to be used to determine the classification of mixtures with regard to acute inhalation toxicity in the absence of contact with water (that is, these formulas are not intended to be used to evaluate mixtures with regard to water-activated toxicity (WAT) hazard). In the case of a mixture which reacts with water to release a gaseous substance, the procedure set out in subsection 8.1.1(2) of the HPR must be used to evaluate the WAT hazard of the mixture. The acute inhalation toxicity of the mixture in the absence of contact with water must be evaluated separately. If there are no data available for the mixture as a whole and bridging principles do not apply, then classification must be determined using the formula in either section 8.1.5 or 8.1.6 of the HPR.

To apply either of these formulas, one must know the ATE and the concentration of each relevant ingredient. In the case of the ingredient which reacts with water to release a gaseous substance, the LC₅₀ of the emitted gaseous substance would not be used as an ATE value. Instead, the ATE and the concentration of the ingredient itself would be used in the calculation according to the formula set out in either section 8.1.5 or 8.1.6 of the HPR.

Ingredients of Unknown Acute Toxicity – Supplemental Label Statement

If a hazardous product is classified in Acute Toxicity (Category 1, 2, 3 or 4) based on ingredient(s) for which the acute toxicity is known and the hazardous product contains 1 or more ingredient(s) of unknown acute toxicity and the ingredient(s) of unknown acute toxicity comprise 1.0% or more of the hazardous product, a prescribed supplemental label element is required.

As specified in paragraph 3(1)(e) of the HPR, the supplemental label element required is as follows:

"[Insert the total concentration in percentage of ingredients with unknown acute toxicity] % of the mixture consists of an ingredient or ingredients of unknown acute toxicity/[Insérez la concentration totale en pourcentage d'ingrédients ayant une toxicité aiguë inconnue] % du mélange consiste en ingredients de toxicité aiguë inconnue"

The route of exposure should be included in the statement. For example, if a hazardous product is classified in Acute Toxicity — Oral — Category 1 based on ingredient(s) for which the acute oral toxicity is known and the hazardous product contains, at a concentration of 5%, ingredients of unknown acute oral toxicity, then the following supplemental label element is required:

5% of the mixture consists of ingredient(s) of unknown acute oral toxicity

The supplemental label element is required only for the route(s) of exposure with respect to which the hazardous product is classified. It could apply more than once in the situation where a mixture ends up being classified for more than 1 route of exposure based on ingredients of known acute toxicity.

For example, if a mixture is classified as acutely toxic through inhalation and oral routes based on ingredient(s) of known acute toxicity, and 2% of this mixture consists of ingredients of unknown acute oral toxicity and 10% of the same mixture consists of ingredients of unknown acute inhalation toxicity, then the following statements must appear on the label of the hazardous product:

2 % of the mixture consists of ingredient(s) of unknown acute oral toxicity

10 % of the mixture consists of ingredient(s) of unknown acute inhalation toxicity

or

2% and 10% of the mixture consists of ingredients of unknown acute oral and inhalation toxicity, respectively.

This supplemental label element is also required by the GHS (seventh revised edition, 2017, paragraph 3.1.3.6.2.2).

Discussion of section 8.1.7 of the Hazardous Products Regulations

As mentioned in subsection 8.1.1(3), in situations where only a range of LD₅₀ (oral or dermal) or LC₅₀ (inhalation) values is available for an ingredient, or only the classification category into which the ingredient falls is known, an ATPE must be determined for the ingredient according to the table in this section. This table provides a single value to be used in the calculation of the ATE for a mixture. The values presented in the table are designed to be used in the calculation of the ATE for classification of a mixture based on its components and do not represent test results.

If the experimentally obtained range of LD₅₀ (oral or dermal) or LC₅₀ values for an ingredient does not fall entirely within any of the ranges set out in the table to this section, the lowest value of the experimentally obtained acute toxicity range must be used as the acute toxicity point estimate for that ingredient.

For example:

1. The available data for substance X indicate that it is only toxic via the oral route and the only available data is an LD₅₀ range of 60 to 150 mg/kg bw. Using the table in section 8.1.7, the ATPE for substance X would be 100 mg/kg bw. This value is then used in the calculation of the ATE of the mixture.
2. The available data for substance Y, a gas, indicate that it falls into Acute Toxicity (Inhalation) — Category 3. Using the table in section 8.1.7, the ATPE for substance Y is 700 ppmV. This value is then used in the calculation of the ATE of the mixture.

Corrosion of the Respiratory Tract

For substances and mixtures that are classified in Acute Toxicity (Inhalation) — Category 1, 2, 3 or 4, if data are available that indicate that the mechanism of toxicity is corrosivity of the substance or mixture, the data should be evaluated to determine whether the substance or mixture is corrosive to the respiratory tract. Corrosion of the respiratory tract is defined as destruction of the respiratory tract tissue after a single, limited period of exposure analogous to skin corrosion; this includes destruction of the mucosa. The corrosivity evaluation could be based on expert judgment using such evidence as: human and animal experience, existing (in vitro) data, pH values, information from similar substances or any other pertinent data (GHS, seventh revised edition, 2017, paragraph 3.1.2.6.5).

If data are available that indicate acute inhalation toxicity with corrosion of the respiratory tract that leads to lethality, then, in addition to the hazard communication elements specified in Section 3 of Annex 3 of the GHS (seventh revised edition) for the category in which the substance or mixture is classified, the corrosion pictogram, as shown in item 4 of Schedule 3 of the HPR, may be added to the label, along with the hazard statement: "corrosive to the respiratory tract".

If data are available that indicate acute inhalation toxicity with corrosion of the respiratory tract and the effect does not lead to lethality, then the hazard would be addressed under the Specific Target Organ Toxicity – Single Exposure or Repeated Exposure hazard class (Subpart 8 or 9, respectively, of Part 8 of the HPR).

Hazard Communication

The symbols, signal words, hazard statements and precautionary statements are specified in section 3 of Annex 3 of the GHS (seventh revised edition) for:

• Acute Toxicity (Oral) – pp. 336-338
• Acute Toxicity (Dermal) – pp. 339-342 and
• Acute Toxicity (Inhalation) – pp. 343-346

Note that item 11(d) ("numerical measures of toxicity") of Schedule 1 of the HPR can include LD₅₀, LC₅₀ and calculated acute toxicity estimates. In all cases, an ATE can be calculated for a mixture. Therefore, an ATE_mix must be disclosed rather than only disclosing the ATE for ingredients in the mixture. Furthermore, the specific route of exposure (oral, dermal, inhalation) for which the ATE_mix has been calculated must also be disclosed on the SDS.

ATE_mix

Hazard communication elements involving multiple routes of exposure

When there is relevant evidence of toxicity by multiple routes of exposure, then classification of a substance or mixture is to be conducted for all appropriate routes of exposure. For example, a substance could be classified in each of Acute Toxicity (Oral) — Category 1, Acute Toxicity (Dermal) — Category 2, and Acute Toxicity (Inhalation) — Category 4. If more than 1 hazard category is assigned, the most severe hazard category must be used to assign the pictogram and signal word. All relevant hazard statement(s) and precautionary statement(s) for each applicable route of exposure and hazard category are still required. Therefore, in the above example, the following hazard communication elements are required on the label and SDS:

Pictogram (for label) or symbol (for SDS): Skull and crossbones

Signal word: Danger

Hazard statements: Fatal if swallowed. Fatal in contact with skin. Harmful if inhaled.

Precautionary statements: A combination of all applicable precautionary

statements for Acute Toxicity (Oral) — Category 1, Acute Toxicity (Dermal) — Category 2 and Acute Toxicity (Inhalation) — Category 4 as listed in section 3 of Annex 3 of the GHS (seventh revised edition).

Supplemental Label Statements

1. Substances which, in contact with water, emit a toxic gas that has an LC₅₀ that falls into 1 of the ranges indicated in Table 3 to subsection 8.1.1(3) of the HPR require a supplemental element on their label and SDS. This requirement is set out in paragraph 3(1)(f) and paragraph 2(b) of Schedule 1 of the HPR.

The wording of the supplemental element is as follows:

• in the case of a released gaseous substance that is classified in Category 1 or 2, "In contact with water, releases gases which are fatal if inhaled/Au contact de l'eau, libère des gaz mortels en cas d'inhalation",
• in the case of a released gaseous substance that is classified in Category 3, "In contact with water, releases gases which are toxic if inhaled/Au contact de l'eau, libère des gaz toxiques en cas d'inhalation", and
• in the case of a released gaseous substance that is classified in Category 4, "In contact with water, releases gases which are harmful if inhaled/Au contact de l'eau, libère des gaz nocifs en cas d'inhalation".

In accordance with paragraph 2(b) of Schedule 1 of the HPR, the above-mentioned information is required to be mentioned under section 2 of the SDS. However, the information could also be mentioned under section 10 of the SDS, since this section provides information on the stability and reactivity of the hazardous product.

2. When an ingredient for which there is no LD₅₀ or LC₅₀ data, nor any information that permits the determination of an ATPE, is present in a mixture at a concentration of 1% or more, it is concluded that the mixture cannot be attributed a definitive ATE. In this situation, the mixture must be classified based on the known ingredients only, and, as specified in paragraph 3(1)(e) and paragraph 2(b) of Schedule 1 of the HPR, a supplemental statement indicating that x percent of the mixture consists of ingredient(s) of unknown toxicity is required on the label and SDS. The wording of the supplemental statement is:

"[Insert the total concentration in percentage of ingredients with unknown acute toxicity] % of the mixture consists of an ingredient or ingredients of unknown acute toxicity/[Insérez la concentration totale en pourcentage d'ingrédients ayant une toxicité aiguë inconnue] % du mélange consiste en ingredients de toxicité aiguë inconnue".

As noted in the discussion of sections 8.1.5 and 8.1.6 of the HPR, this supplemental statement could apply more than once, in the situation where a mixture ends up being classified for more than 1 route of exposure based on the known ingredients only.

Classification of Acute Toxicity for Substances Examples

Example 8.1.2: Evaluation of the acute oral toxicity of a substance in rats (ECHA Guidance, 2017, paragraph 3.1.5.1.3)

Available data

The substance is a corrosive, volatile liquid.

In an acute oral toxicity study in rats, the following results were observed:

• At a test dose of 200 mg/kg bw:
  • no mortality
  • only transient symptoms and
  • no necropsy findings
• At a test dose of 500 mg/kg bw:
  • 100% mortality
  • signs of toxicity: poor general state; and
  • necropsy findings: hyperemia in stomach (due to local irritation/corrosivity), no other organs affected

Classification

Acute Toxicity (Oral) — Category 3

Rationale

Based on this information, the LD₅₀ is somewhere between 200 and 500 mg/kg bw. However, 200 mg/kg bw is within the range for Category 3 and 500 mg/kg bw is within the range for Category 4 (see Table to section 8.1.7 of the HPR). In such a situation, the lowest value of the experimentally obtained acute toxicity range (200 mg/kg) should be used for the acute toxicity point estimate. Therefore, in accordance with subsection 8.1.1(3) of the HPR the substance classifies in Acute Toxicity (Oral) — Category 3.

Example 8.1.3: Evaluation of the acute dermal toxicity of a substance in rabbits (ECHA Guidance, 2017, paragraph 3.1.6.1.4)

Available data

In an acute dermal toxicity study with rabbits the following test data results were reported:

• At the dose level of 50 mg/kg bw: no mortality was observed.
• At 200 mg/kg bw: 100% mortality was observed.

Classification

Acute Toxicity (Dermal) — Category 2.

Rationale

The dermal LD₅₀ is greater than 50 mg/kg bw and less than 200 mg/kg bw. According to Table 2 to subsection 8.1.1(3), this range corresponds to Acute Toxicity (Dermal) — Category 2.

Classification of Acute Toxicity for Mixtures Examples

Example 8.1.4: Evaluation of the acute toxicity of a mixture for which the dermal route of exposure is relevant.

Available data

No test data is available for the whole mixture. Bridging principles are not applicable since no test data on similar mixtures are available. Therefore, classification is based on ingredients. The dermal LD₅₀ values of each ingredient are as follows:

Table 8.1 Dermal LD₅₀ values of each ingredient in Example 8.1.4

Ingredient	% (weight/weight)	LD50 (dermal, rat)
Ingredient 1	45	400 mg/kg bw
Ingredient 2	30	300 mg/kg bw
Ingredient 3	25	2,300 mg/kg bw

Classification

Acute Toxicity (Dermal) — Category 3.

Rationale

The additivity formula set out in section 8.1.5 is used because information is available for all ingredients.

ATE_mix= 100 divided by (45/400 + 30/300 + 25/2300) ATE_mix = 100/0.223 = 448 mg/kg bw.

According to Table 2 to subsection 8.1.1(3), this value corresponds to Acute Toxicity (Dermal) — Category 3.

Example 8.1.5: Evaluation of the acute toxicity of a mixture for which the oral route of exposure is relevant.

Available data

No test data are available for the whole mixture.

Classification via the application of bridging principles is not possible since no test data on similar mixtures are available. Therefore, classification is based on ingredient data.

The oral LD₅₀ value and the classification of each ingredient are as follows:

Table 8.2 Oral LD₅₀ values of each ingredient in Example 8.1.5

Ingredient	% (weight/weight)	Acute Toxicity Classification	Oral LD50
Ingredient 1	4	Oral Category 3	125 mg/kg bw
Ingredient 2	92	Not classified	No data available
Ingredient 3	3.1	Oral Category 4	1500 mg/kg bw
Ingredient 4	0.9	Not classified	No data available

Classification

Acute Toxicity (Oral) — Category 3

Rationale

The additivity formula set out in subparagraph 8.1.6(b)(ii) is used because the total concentration of ingredients with unknown acute toxicity is 92% (the concentration of ingredient 2), which is above 10%. Ingredient 4 is present below the concentration limit of 1% for relevant ingredients, and the provision in subsection 2.5(1) of the HPR does not apply. Therefore, ingredient 4 it is not used in the calculation.

ATE_mix = (100 – 92)/(4/125 + 3.1/1500) = 235 mg/kg bw.

According to Table 2 to subsection 8.1.1(3), this value corresponds to Acute Toxicity (Oral) — Category 3.

As required by paragraph 3(1)(e) and paragraph 2(b) of Schedule I of the HPR, the following supplemental statement must be provided on the label and SDS:

"92% of the mixture consists of an ingredient of unknown acute oral toxicity."

Example 8.1.6: Evaluation of the acute toxicity of a mixture for which the oral route of exposure is relevant.

Available data

No test data are available for the whole mixture. Classification via the application of bridging principles is not possible since no test data on similar mixtures are available. Therefore, classification is based on ingredient data.

The oral LD₅₀ value and the classification of each ingredient are as follows:

Table 8.3 Oral LD₅₀ values of each ingredient in Example 8.1.6

Ingredient	%(weight/ weight)	Acute Toxicity Classification	Oral LD50
Ingredient 1	75	Oral Category 4	1600 mg/kg bw
Ingredient 2	5	Unknown	Acute toxicity range estimate: 200 mg/kg bw < oral LD50 < 2000 mg/kg bw
Ingredient 3	20	Not classified under the HPR, but according to the GHS, would classify in Oral Category 5	3000 mg/kg bw

Classification

Acute Toxicity (Oral) — Category 4

Rationale

The additivity formula set out in section 8.1.5 is used because information is available for all ingredients. For ingredients 1 and 3, the oral LD₅₀ values are known, so these LD₅₀ values are used as the ATEs of ingredients 1 and 3.

For ingredient 2, the oral LD₅₀ falls between 200 and 2000 mg/kg bw. The experimentally- obtained acute toxicity range estimate of 200 mg/kg bw < oral LD₅₀ < 2000 mg/kg bw does not fall entirely within any of the ranges provided in the table in section 8.1.7. As per subsection 8.1.7(2) of the HPR, for ingredient 2, the converted acute toxicity point estimate is 200 mg/kg bw (the lowest value of the experimentally- obtained acute toxicity range).

ATE_mix= 100 divided by (75/1600 + 5/200 + 20/3000) ATE_mix = 100/0.07854 = 1273.2 mg/kg bw.

According to Table 2 to subsection 8.1.1 (3), this value corresponds to Acute Toxicity (Oral) — Category 4.

Subpart 2 Skin Corrosion / Irritation

Definitions

Discussion – skin corrosion vs skin irritation

Skin corrosion and skin irritation both refer to the production of local damage to the skin after exposure to a mixture or substance. Severity of the damage and the reversibility of the lesions are assessed. Skin corrosion is irreversible damage. Skin irritation is reversible and the affected sites are repaired within the observation period of the test (normally 14 days).

The HPR definition of skin corrosion provides details that are not included in the corresponding definition in the GHS (seventh revised edition, 2017, paragraph 3.2.1.1), namely, the following: "and includes ulcers, bleeding, bloody scabs and, within a 14-day observation period, discoloration due to blanching of the skin, complete areas of alopecia, and scars". These details were retained in the HPR, from the fifth revised edition of the GHS, because they provide additional information on what the definition of skin corrosion can include, without limiting the definition.

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of section 8.2.1 of the Hazardous Products Regulations

There is an order in which all data must be considered for the purpose of classification in this hazard class. This order applies to the classification of both substances and mixtures. The steps to consider are listed, in order, below. More detail on each step is provided in the discussion of sections 8.2.2 to 8.2.7 of the HPR.

1. Positive human data meeting classification criteria outlined in subsection 8.2.2(1) are used to classify a substance in Skin Corrosion — Category 1.
2. Positive animal data (derived from a study specifically designed to test skin corrosion and/or irritation) that meet classification criteria outlined in subsection 8.2.2(2) are used to classify a substance in Skin Corrosion — Category 1, with further classification in subcategory 1A, 1B or 1C (if possible).
3. Positive human data or positive animal data (derived from a study specifically designed to test skin corrosion and/or irritation) that meet classification criteria outlined in subsection 8.2.2(3) are used to classify a substance in Skin Irritation — Category 2.
4. Negative human data or negative animal data (derived from a study specifically designed to test skin corrosion and/or irritation) are used to determine that the substance does not meet classification criteria for this hazard class. If the conditions outlined in subsection 8.2.2(4) are met, progression to subsequent steps is not required. However, progression through the subsequent steps is necessary if there is no or insufficient negative data available.
5. Positive animal data derived from a dermal exposure study that was not specifically designed to test skin corrosion and/or irritation (for example, acute or subchronic dermal toxicity), but that otherwise meets classification criteria outlined in section 8.2.2 are used to classify a substance in Skin Corrosion — Category 1 or Skin Irritation — Category 2, as appropriate.
6. Positive in vitro or ex vivo data that meet classification criteria outlined in section 8.2.4 are used to classify a substance in Skin Corrosion — Category 1 or Skin Irritation — Category 2, as appropriate.
7. Substances with pH extremes (≤2.0 or ≥11.5), as outlined in section 8.2.5, are considered and, if criteria are met, are classified in Skin Corrosion — Category 1.
8. Positive structure-activity data that meet classification criteria outlined in subsection 8.2.6(1) or 8.2.6(2) are used to classify a substance in Skin Corrosion — Category 1 or Skin Irritation — Category 2, as appropriate.
9. Finally, all the available evidence must be considered together, as described in section 8.2.7, to determine if classification in Skin Corrosion — Category 1 (with further classification into subcategory 1A, 1B or 1C, if possible) or Skin Irritation — Category 2 is warranted.

If, following step 9, a classification has not been determined, it can be concluded that the substance does not meet the criteria for classification in the Skin Corrosion/Irritation hazard class.

Figure 29 - Text description

This is a flow diagram that illustrates an evaluation sequence for skin corrosion and irritation potential. According to the first step, if there are positive human data for corrosion, then classification in Category 1 is the result. For the second step, if purposely generated animal data indicate corrosion, then classification in Category 1A, 1B or 1C is the result. For the third step, if human or purposely generated animal data indicate irritation, then classification in Category 2 is the result.

For the fourth step, if human and purposely generated animal data indicate no corrosion or irritation, then the substance is not classified. For the fifth step, if other dermal animal data indicate corrosion or irritation, then classification in Category 1 or 2, respectively, is the result. For the sixth step, if in vitro or ex vivo data indicate corrosion or irritation, then classification in Category 1 or 2, respectively, is the result.

For the seventh step, if the pH is less than or equal to 2 or greater than or equal to 11.5, in the absence of alkali/acid reserve effect, then classification in Category 1 is the result. For the eighth step, if SAR indicates corrosion, then classification in Category 1 is the result. For the ninth step, if SAR indicates irritation, then classification in Category 2 is the result.

For the 10th step, if the totality of available data supports a conclusion of corrosivity or irritation, then classification in Category 1 or 2, respectively, is the result. For the last step, if the answer is 'No' to all the previous steps, then the substance cannot be classified.

Discussion of subsection 8.2.2(1) of the Hazardous Products Regulations

Human data demonstrating skin corrosion are considered first. Data which meet the criteria for skin corrosion result in the classification of a substance in Skin Corrosion — Category 1. Positive human data that are insufficient to meet the criteria for skin corrosion are evaluated again, as follows:

• in the assessment for skin irritation – refer to paragraph 8.2.2(3)(a) of the HPR, or
• in the final step of evaluation – refer to section 8.2.7 of the HPR

Negative results are taken into consideration in a later step – refer to subsection 8.2.2(4) of the HPR.

Note: There is no stipulation on the exposure time for human data used as the basis of classification of a substance in Skin Corrosion — Category 1.

Discussion of subsection 8.2.2(2) of the Hazardous Products Regulations

Animal data demonstrating skin corrosion is the second step of the evaluation. Data must be derived from "purposely generated animal data", which means data obtained from an animal study designed specifically to test skin corrosion and/or irritation. Acute dermal toxicity, skin sensitization, subchronic dermal toxicity or other studies that permit observation of skin reactions but are not specifically designed to study skin corrosion and/or skin irritation are considered in a later step – refer to section 8.2.3 of the HPR.

Skin Corrosion — Category 1 has 3 subcategories: 1A, 1B and 1C. If the data do not permit sub-categorization, the substance would simply be classified in Category 1. For example, it is possible that a 3 minute (or less) exposure could result in irreversible damage to the skin after more than a 1 hour observation period. In this case, the substance must be classified in Skin Corrosion — Category 1 without further sub-categorization.

In all cases of sub-categorization, a positive result for at least 1 animal is required for classification.

Negative results from purposely generated animal studies are taken into consideration in a later step – refer to subsection 8.2.2(4) of the HPR.

Discussion of subsection 8.2.2(3) of the Hazardous Products Regulations

When human or animal data is available but insufficient to meet classification criteria for skin corrosion, the data must also be evaluated for skin irritation. Reversibility of skin lesions is taken into consideration when evaluating irritant responses.

Animal data acquired from a test performed in accordance with OECD TG 404 - Acute Dermal Irritation/Corrosion, as amended from time to time, are evaluated based on scoring values specified in that test. The mean scores per animal for erythema and eschar, or edema are calculated separately. For each test animal, the average scores for 3 consecutive days (24, 48 and 72 hours) are determined. Where 3 animals have been tested, if 2 of the animals meet or exceed the cut-off value of 2.3/4.0 for erythema and eschar, or for edema the substance must be classified in Skin Irritation — Category 2.

Where more than 3 animals have been tested, scores for each animal are calculated in the same manner as described above and applied according to the number of animals tested, as follows:

6 rabbits tests: mean score of ≥ 2.3 and ≤ 4.0 for erythema and eschar or for edema in at least 4 out of 6 animals

5 rabbits tests: mean score of ≥ 2.3 and ≤ 4.0 for erythema and eschar or for edema in at least 3 out of 5 animals

4 rabbits tests: mean score of ≥ 2.3 and ≤ 4.0 for erythema and eschar or for edema in at least 3 out of 4 animals (GHS, seventh revised edition, 2017, paragraphs 3.2.5.3.3 to 3.2.5.3.5)

The substance must be classified in Skin Irritation — Category 2 when:

• the criteria in b(i) of the Table to subsection 8.2.2(3) of the HPR are met or
• scores are insufficient to meet the criteria in b(i) of the Table to subsection 8.2.2(3) or are not provided, and inflammation persists in 2 or more tested animals to the end of the observation period specified by the scientifically validated method used to generate the data. Signs of inflammation are alopecia (hair loss) in a limited area, hyperkeratosis, hyperplasia and scaling (see criteria b(ii) of the Table to subsection 8.2.2(3))

Note that complete areas of alopecia, blanching, scars, and visible necrosis are indicators of corrosion and a Skin Corrosion — Category 1 classification may be more appropriate.

Sometimes, only 1 animal is tested for substances that are suspected corrosives. In this case, as well as cases where more than 1 animal is tested but only 1 animal exhibits severe skin irritation and no animals exhibit skin corrosion, the substance is classified in Skin Irritation — Category 2 if criteria as outlined in subparagraph 8.2.2(3)(b)(iii) are met.

Only positive results from human or animal data are considered. Negative results are considered in the classification step detailed in subsection 8.2.2(4) of the HPR.

Discussion of subsection 8.2.2(4) of the Hazardous Products Regulations

In this step, negative human data or negative animal data derived from a skin corrosion and/or skin irritation study can be used to determine that the substance is not a skin corrosive or skin irritant.

In the case of a purposely-generated animal study, at least 3 test animals have to be assessed and all the conditions of subsection 8.2.2(4) must be met in order to conclude that the substance is not a skin corrosive or skin irritant.

If all the conditions of subsection 8.2.2(4) of the HPR are met, the substance can be considered as not classified under this hazard class and there is no requirement to progress further in the evaluation process for this endpoint. However, progression through the subsequent steps is necessary if no data or insufficient negative data are available.

Discussion of section 8.2.3 of the Hazardous Products Regulations

Animal data from studies other than those specifically designed to test for skin corrosion and/or skin irritation must be evaluated if it has not been conclusively established that the substance is not a skin corrosive or skin irritant according to subsection 8.2.2(4) of the HPR. These data include, for example, acute dermal (LD₅₀) toxicity studies, sub-chronic dermal toxicity studies, and skin sensitization studies, which also permit observation of skin reactions to topically applied test substances. Only positive results from such studies are considered for the classification of the substance.

Discussion of section 8.2.4 of the Hazardous Products Regulations

Once in vivo human and animal data have been evaluated, in vitro and/or ex vivo data must be evaluated for skin corrosion and skin irritation. Only positive results can be considered for the classification at this step.

Examples of scientifically validated test methods for Skin Corrosion — Category 1 include:

• OECD TG 430 –Transcutaneous Electrical Resistance (TER) Test Method. Using rat skin, the test substance is determined to be corrosive to skin if:
• the mean TER value is ≤ 5 kΩ (kiloohm) and the skin discs are obviously damaged; or
• the mean TER value is ≤ 5 kΩ, and the skin discs show no obvious damage, but the mean disc dye content is ≥ the mean disc dye content of the 10M HCl positive control obtained concurrently.
• OECD TG 431 –Reconstructed Human Epidermis Test Method. 4 possible prediction models are used: EpiSkin™, EpiDerm™ SCT, SkinEthic™ RHE, epiCS^®and LabCyte EPI-MODEL24 SCT. Table 8.4 below summarizes how the classification criteria apply to each test.

Table 8.4 Application of classification criteria for OECD TG 431 data.

Prediction Model	Viability	Classification
EpiSkin™	< 35% after 3 minute exposure	Category 1 (1A optional)
	≥ 35% after 3 minute exposure and < 35% after 60 minutes	Category 1 (1B and 1C optional)
	≥ 35% after 60 minute exposure and < 35% after 240 minutes	Category 1 (1B and 1C optional)
	≥ 35 % after 240 minute exposure	Non-corrosive
EpiDerm™ SCT, SkinEthic™ RHE, epiCS®and LabCyte EPI-MODEL24 SCT	< 50% after 3 minute exposure	Category 1
	≥ 50% after 3 minute exposure and < 15% after 60 minutes	Category 1
	≥ 50% after 3 minute exposure AND ≥ 15% after 60 minute exposure	Non-corrosive
EpiDerm™ SCT If identified as corrosive	< 25% after 3 minute exposure	Category 1A (optional)
	≥ 25% after 3 minute exposure	Category 1B and 1C (optional)
SkinEthic™ RHE If identified as corrosive	< 18% after 3 minute exposure	Category 1A (optional)
	≥ 18% after 3 minute exposure	Category 1B and 1C (optional)
epiCS® and LabCyte EPI-MODEL24 SCT If identified as corrosive	< 15% after 3 minute exposure	Category 1A (optional)
	≥ 15% after 3 minute exposure	Category 1B and 1C (optional)

• OECD TG 435 – In vitro Membrane Barrier Test Method (for example, Corrositex^®prediction model). Using a synthetic membrane barrier and a chemical detection system, barrier damage is measured after the application of the test chemical to the surface of the membrane barrier. The mean breakthrough time of the chemical through the membrane barrier is measured. Table 8.5 summarizes how the test results apply to classification. This method is mostly applicable to acids and bases and may not be suitable for solutions with pH values between 4.5 and 8.5.

Table 8.5: Application of classification criteria for OECD TG 435 Corrositex^® prediction model.

	Mean breakthrough time
Prediction	Test chemicals with high acid/alkaline reserve	Test chemicals with low acid/alkaline reserve
Corrosive Optional Skin Corrosion — Category 1A	≤ 3 minutes	≤ 3 minutes
Corrosive Optional Skin Corrosion — Category 1B	> 3 minutes to ≤ 1 hour	> 3 minutes to ≤ 30 minutes
Corrosive Optional Skin Corrosion — Category 1C	> 1 hour to ≤ 4 hours	> 30 minutes to ≤ 60 minutes
Non-corrosive	> 4 hours	> 60 minutes

An example of a scientifically validated in vitro test method for Skin Irritation — Category 2 is:

• OECD TG 439 – Reconstructed Human Epidermis Test Method. The test substance is classified in Skin Irritation — Category 2 if the tissue viability after exposure and post-treatment incubation is ≤ 50% and the test chemical is found to be noncorrosive. Since the Reconstructed Human Epidermis test methods covered by this test guideline cannot resolve between GHS categories 1 and 2, further information on skin corrosion is required to decide on its final classification.

Note: In vitro and ex vivo data can only be used for classification when the tested substance is within the applicability domain of the test method(s) used.

(Details on test methods from website: OECD Guidelines for Testing of Chemicals, Section 4 – Health Effects)

Discussion of section 8.2.5 of the Hazardous Products Regulations

A pH of ≤ 2.0 or ≥ 11.5 for a substance is sufficient to trigger its classification in Skin Corrosion — Category 1 under section 8.2.5 of the HPR, unless data available from an assessment of alkali or acid reserve supports the conclusion that the substance need not be classified based on its pH. The acid or alkaline reserve is a measure of the buffering capacity of substances. In general, the higher the buffering capacity, the higher the potential for corrosivity.

Note: At the time of writing this guidance, there is no validated and internationally accepted method for assessing acid or alkaline reserve (buffering capacity).

If the pH of a substance is ≤ 2.0 or ≥ 11.5 but an assessment of alkali or acid reserve supports the conclusion that the substance need not be classified based on its pH, it is necessary to proceed to the next step in the classification procedure (section 8.2.6 of the HPR).

If the pH of a substance is > 2 or < 11.5, it is necessary to proceed to the next step in the classification procedure (section 8.2.6 of the HPR).

Discussion of subsections 8.2.6(1) and 8.2.6(2) of the Hazardous Products Regulations

If none of the criteria in section 8.2.2 through section 8.2.5 of the HPR have been met, then a structure-activity relationship (SAR) must be considered as potential evidence in support of classification. The SAR can be used to conclude that the substance is a skin corrosive or a skin irritant, but cannot be used to conclude that the substance is not a skin corrosive or skin irritant.

Discussion of section 8.2.7 of the Hazardous Products Regulations

As a final step in determining the classification of a substance in this hazard class, all available information must be considered. Evidence that, at some or all of the previous steps in the evaluation, were insufficient to lead to classification must be considered together. If, when considered together, the evidence warrants the classification of the substance as a skin corrosive or skin irritant, the substance must be classified accordingly.

If, following this evaluation, it is determined that there is insufficient data to support classification of a substance as a skin corrosive or skin irritant, the substance is not classified in this hazard class.

Classification in a Category or Subcategory of the Class

Classification of Mixtures

Discussion of section 8.2.8 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for skin corrosion or skin irritation, which means that the procedures described in sections 8.2.9 to 8.2.11 must be followed in the order in which these sections appear in the HPR. As specified in subsection 8.2.9(1), if there are test data for the mixture as a whole, these data may be used to classify the mixture, unless, according to subsection 8.2.2(4), the mixture need not be classified. As specified in subsection 8.2.9(2), if test data are available for the mixture as a whole, but the mixture cannot be classified, then the procedures described in sections 8.2.10 and 8.2.11 must be followed.

Section 8.2.10 specifies which bridging principles may be applied to this hazard class. Finally, according to section 8.2.11, if there are no test data available for the mixture as a whole and bridging principles cannot be applied, then the classification of mixtures for skin corrosion or skin irritation is based on the evaluation of available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified in this hazard class.

Discussion of subsection 8.2.9(1) of the Hazardous Products Regulations

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is the same as for substances, and is carried out in accordance with the order of section 8.2.2 to section 8.2.7 of the HPR. Therefore, the discussions corresponding to these sections and the discussion corresponding to Part 2 of the HPR are relevant to the classification of mixtures if there are data available for the mixture as a whole.

If data meet the criteria found in sections 8.2.2 through 8.2.7, then the mixture must be classified within the category whose criteria are met.

For example, if there are no human, animal, in vitro or ex vivo test data available for the mixture as a whole, however, the pH of the mixture can be measured and meets the criteria outlined in section 8.2.5 (pH ≤ 2.0 or ≥ 11.5), the mixture must be classified in Skin Corrosion – Category 1. Evaluation of the mixture can stop at this point and there is no need to assess bridging principles (section 8.2.10) or evaluate information available on individual ingredients of the mixture (section 8.2.11).

Likewise, if there are data on the mixture as a whole that meet the criteria of subsection 8.2.2(4) (i.e., human or purposely generated animal data indicating that the tested substance is not a skin corrosive or skin irritant), then there is no requirement to progress further in the evaluation process. The mixture is not classified in this hazard class.

With regard to section 8.2.4 of the HPR, it is important to note that in vitro and ex vivo data generated from validated test methods may not have been validated using mixtures. Although these methods are considered broadly applicable to mixtures, they can only be used for classification of mixtures when all ingredients of the mixture fall within the applicability domain of the test methods used.

Discussion of subsection 8.2.9(2) of the Hazardous Products Regulations

If, following the evaluation process outlined in subsection 8.2.9(1) of the HPR, the mixture as a whole cannot be classified, and the mixture cannot be excluded from classification based on applicable negative data (subsection 8.2.2(4)), then the classification must proceed through, in order, section 8.2.10 and section 8.2.11.

Discussion of section 8.2.10 of the Hazardous Products Regulations

Section 8.2.10 of the HPR describes the second step in the tiered approach for the classification of mixtures for skin corrosion/irritation.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

All of the bridging principles are applicable to the Skin Corrosion/Irritation hazard class, namely: dilution, production batches, increase in concentration of hazardous ingredient, interpolation, substantially similar mixtures, and aerosols.

If the bridging principles cannot be applied to classify as Skin Corrosion — Category 1 or Skin Irritation — Category 2, then it is necessary to proceed to the third step in the tiered approach for the classification of mixtures.

Discussion of subsection 8.2.11(1) of the Hazardous Products Regulations

If a classification for the mixture has not been determined following the application of sections 8.2.9 and 8.2.10 of the HPR, then data available for the ingredients of the mixture must be considered as the final step in the tiered approach for the classification of mixtures in this hazard class.

Application of this section considers as "relevant ingredients", ingredients that are present in concentrations at or above 1.0% (w/w for solids, liquids, dusts, mists and vapours and v/v for gases) unless there is an indication that an ingredient present at < 1.0% has corrosive or irritant properties at that concentration. Paragraph 8.2.11(1)(b) builds on the concept found in subsection 2.5(1), where it is stated that the mixture is classified based on ingredients present below the concentration limit that still present the hazard of the hazard class. These ingredients must be considered as part of the additivity approach to determine the classification of the mixture.

The concentrations of all relevant ingredients are summed according to the rules outlined in subsection 8.2.11(2), unless the mixture contains ingredients for which the additivity approach cannot be applied. The approach for mixtures with 1 or more particular ingredients for which the additivity approach does not apply is discussed in subsection 8.2.11(3).

Discussion of subsection 8.2.11(2) of the Hazardous Products Regulations

The order of precedence for applying additivity is from paragraph 8.2.11(2)(a) through paragraph 8.2.11(2)(d) of the HPR. For this subsection, what is considered a "relevant ingredient" is identified in subsection 8.2.11(1).

If the sum of all relevant ingredients classified in Skin Corrosion — Category 1 totals 5.0% or more, the mixture is classified in Skin Corrosion — Category 1.

If the sum of all relevant ingredients classified in Skin Corrosion — Category 1A totals 5.0% or more, and there are no ingredients classified in Category 1 or subcategories 1B or 1C, the mixture is classified in Skin Corrosion — Category 1 or the subcategory Skin Corrosion — Category 1A.

If the sum of all relevant ingredients classified in Skin Corrosion — Category 1B totals 5.0% or more, and there are no ingredients classified in Category 1 or subcategories 1A or 1C, the mixture is classified in Skin Corrosion — Category 1 or the subcategory Skin Corrosion — Category 1B.

If the sum of all relevant ingredients classified in Skin Corrosion — Category 1C totals 5.0% or more, and there are no ingredients classified in Category 1 or subcategories 1A or 1B, the mixture is classified in Skin Corrosion — Category 1 or the subcategory Skin Corrosion — Category 1C.

If the sum of all relevant ingredients classified in 2 or more of the following categories or subcategories is equal to or greater than 5.0%, the mixture is classified in the category "Skin Corrosion ─ Category 1":

• Skin Corrosion — Category 1
• Skin Corrosion — Category 1A
• Skin Corrosion — Category 1B
• Skin Corrosion — Category 1C

If the sum of all relevant ingredients classified in Skin Corrosion — Category 1, 1A, 1B or 1C is ≥ 1.0% but < 5.0%, the mixture is classified in Skin Irritation — Category 2.

If the mixture contains relevant Skin Irritation — Category 2 ingredients, the concentrations of those ingredients are summed, and if the sum is 10.0% or more, the mixture is classified in Skin Irritation — Category 2.

If the mixture contains relevant Skin Corrosion — Category 1, 1A, 1B or 1C ingredients, and relevant Skin Irritation — Category 2 ingredients, a weighting factor of 10 is applied to the sum of the Category 1, 1A, 1B and 1C ingredients. 10 times the sum of concentrations for Category 1, 1A, 1B and 1C ingredients added to the sum of concentrations of Category 2 ingredients must total 10.0% or more for the mixture to be classified in Skin Irritation — Category 2.

Table 8.6: Concentration of ingredients of a mixture that triggers classification in the Skin Corrosion — Category 1, 1A, 1B or 1C or Skin Irritation — Category 2 hazard class.

Sum of ingredients classified in:	Concentration triggering classification of a mixture in:
	Skin Corrosion	Skin Corrosion	Skin Corrosion	Skin Corrosion	Skin Irritation
	Category 1	Category 1A	Category 1B	Category 1C	Category 2
Skin Corrosion — Category 1, 1A, 1B and 1C	≥ 5%	N/A	N/A	N/A	≥ 1% but < 5%
Skin Corrosion Category 1A	N/A	≥ 5%Footnote 1	N/A	N/A	N/A
Skin Corrosion Category 1B	N/A	N/A	≥ 5%Footnote 2	N/A	N/A
Skin Corrosion Category 1C	N/A	N/A	N/A	≥ 5%Footnote 3	N/A
Skin Corrosion — Category 2	N/A	N/A	N/A	N/A	≥ 10%
(10 × Skin Corrosion — Category 1, 1A, 1B and 1C) + Skin Irritation Category 2	N/A	N/A	N/A	N/A	≥ 10%
1 If there are no ingredients classified in Category 1 or subcategories 1B or 1C. Can also be classified as Skin Corrosion Category 1. Return to footnote 1 referrer 2 If there are no ingredients classified in Category 1 or subcategories 1A or 1C. Can also be classified as Skin Corrosion Category 1. Return to footnote 2 referrer 3 If there are no ingredients classified in Category 1 or subcategories 1A or 1B. Can also be classified as Skin Corrosion Category 1. Return to footnote 3 referrer (Category 1 and Category 2 based on GHS, seventh revised edition, 2017, Table 3.2.3)

Discussion of subsection 8.2.11(3) of the Hazardous Products Regulations

The additivity approach explained in subsection 8.2.11(2) of the HPR might not apply for certain types of substances such as acids and bases, inorganic salts, aldehydes, phenols, and surfactants given that many such substances could be corrosive or irritant at concentrations less than those established for the additivity approach.

Therefore, subsection 8.2.11(3) specifies that a mixture must be classified in Skin Corrosion — Category 1 or Skin Irritation — Category 2 based on a single ingredient of the types indicated in Column 2 of the Table in subsection 8.2.11(3) that exceeds the concentration limits listed in Column 3 of the same table. Please note that Column 2 of Item 3 states "Other ingredients classified in the category "Skin Corrosion — Category 1"", which includes ingredients classified in the categories "Skin Corrosion — Category 1A", "Skin Corrosion — Category 1B" and "Skin Corrosion — Category 1C".

Hazard Communication

The required symbols, signal words, hazard statements and precautionary statements for Skin Corrosion/Irritation Categories 1 and 2 are specified in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, pp. 347-348), subject to paragraphs 3(5)(e), (f) and (g) of the HPR. These paragraphs specify that if the hazardous product is classified in:

• Skin Corrosion — Category 1, the information elements specified in the GHS for Skin Corrosion/Irritation — Category 1A apply
• Skin Corrosion — Category 1A, 1B or 1C, the information elements specified in the GHS for Skin Corrosion/Irritation — Category 1A to 1C apply and
• Skin Irritation — Category 2, the information elements specified in the GHS for Skin Corrosion/Irritation — Category 2 apply.

Note: Products classified in Skin Corrosion — Category 1 do not also have to be labelled with the information elements for Serious Eye Damage — Category 1, even if they meet the criteria for classification in that category, because:

1. according to subsection 3.6(2), if there is a requirement to provide the hazard statement "Causes severe skin burns and eye damage" any requirement to provide the hazard statement "Causes serious eye damage" does not apply;
2. the required signal word and symbol are the same for both hazard classes; and
3. the precautionary statements for Skin Corrosion — Category 1, 1A, 1B, and 1C include the precautionary statements for Serious Eye Damage — Category 1.

Classification of Skin Corrosion/Irritation for Substances Examples

Example 8.2.1: Standard OECD TG 404 with 3 test animals (ECHA Guidance, 2017, pp. 297-298)

Available data

1. Human data: not available
2. Animal data: No necrosis was observed.

The scoring results following a 4-hour application are:

Table 8.7: Standard OECD TG 404 test scoring results for erythema and edema on 3 rabbits following a 4-hour application.

Rabbit No.	Erythema:						Edema:
	1h	24h	48h	72h	7d	14d	1h	24h	48h	72h	7d	14d
1	3	3	3	2	0	-	1	2	2	2	0	-
2	3	3	3	3	0	-	1	2	2	1	0	-
3	1	1	1	0	0	-	1	1	1	1	0	-

Classification

Skin Irritation — Category 2

Rationale

The mean erythema and edema scores, respectively, for each rabbit over the time periods 24, 48 and 72 hours are:

• Rabbit 1= 2.7 and 2.0
• Rabbit 2 = 3 and 1.7
• Rabbit 3 = 0.66 and 1

2 of the 3 rabbits have a mean score for erythema that exceeds the cut-off of 2.3 as specified in the Table to subsection 8.2.2(3) of the HPR.

Example 8.2.2: OECD TG 404 test with more than 3 test animals (ECHA Guidance, 2017, p. 298)

Available data

1. Human data: not available
2. Animal data: No necrosis was observed.

The scoring results following a 4-hour application are:

Table 8.8 OECD TG 404 test scoring results for erythema and edema on 4 rabbits following a 4-hour application.

Rabbit No.	Erythema:						Edema:
	1h	24h	48h	72h	7d	14d	1h	24h	48h	72h	7d	14d
1	3	3	2	2	1	0	2	3	2	2	1	0
2	3	2	2	2	1	0	2	2	2	2	1	0
3	2	2	1	1	1	0	2	2	2	2	1	0
4	2	2	1	1	1	0	2	2	2	2	1	0

Classification

Not classified

Rationale

The mean erythema and edema scores, respectively, for each rabbit over the time periods 24, 48 and 72 hours are:

• Rabbit 1= 2.3 and 2.3
• Rabbit 2 = 2 and 2
• Rabbit 3 = 1.3 and 2
• Rabbit 4 = 1.3 and 2

The mean erythema and edema scores for only 1 of the 4 animals reached the cut-off score of 2.3. When 4 rabbits are tested, results for 3 of the 4 animals need to meet or exceed the cut-off value for classification in Skin Irritation — Category 2.

Classification of Skin Corrosion/Irritation for Mixtures Example

Classification based on the classified ingredients (ECHA Guidance, 2015, p. 298)

Available data

Data for the mixture as a whole is not available other than the pH which was measured as 9.0-10.0. There is insufficient information available to apply the bridging principles. Therefore, classification is based on the classified ingredients.

Table 8.9: Classification of skin corrosion/irritation for mixtures based on the classified ingredients.

Ingredient	Skin Corrosion/Irritation Classification	Concentration (%w/w)
Substance A	Skin Irritation — Category 2	1.8
Substance B	Not classified	0.5
Substance C	Skin Irritation — Category 2	5.4
Substance D	Not classified	4.0
Acid (with pH >2)	Skin Corrosion — Category 1A	2.0
Water	Not classified	86.3

Classification

Skin Irritation — Category 2

Rationale

1. The pH of the mixture does not meet the criteria specified in section 8.2.5 of the HPR.
2. Substance B, substance D and water can be disregarded as they are not classified for skin-corrosion or skin-irritation.
3. The mixture contains 2.0% Acid as the only Skin Corrosion — Category 1 ingredient. The acid is present at 2.0%, which is less that the 5.0% cut-off established for Category 1A ingredients in paragraph 8.2.11(2)(a.1) of the HPR. The concentration of the acid does, however, meet the cut-off values (≥ 1% but < 5%) established for Category 1, 1A, 1B and 1C ingredients in paragraph 8.2.11(2)(b) of the HPR. Therefore, the mixture must be classified in Skin Irritation — Category 2.

Note that, in this example, ingredients A and C do not impact the overall classification of the mixture in Skin Irritation — Category 2.

Subpart 3 Serious Eye Damage / Eye Irritation

Discussion – eye irritation vs serious eye damage

Eye irritation refers to the production of reversible changes in the eye after exposure to a mixture or substance. Serious eye damage refers to eye tissue that is damaged or serious physical decay of vision and the effects are either not reversible or not fully reversible within 21 days, after exposure to a mixture or substance.

The use of the term "physical" to describe decay of vision excludes neurological damage that affects vision. This hazard class assesses physical damage to the eye, rather than neurological damage. Neurological damage that affects the processing or transmission of information from the eye is not included in this hazard class, but could be considered for classification under STOT-SE or STOT-RE.

The GHS (seventh revised edition, 2017, paragraph 3.3.1.1) does not specify "within an observation period of 21 days" for the eye irritation definition. This was retained in the eye irritation definition in the HPR, from the fifth revised edition of the GHS. This is because Table 3.3.2 of the GHS describes eye irritation effects that are fully reversible within an observation period of 21 days or less after exposure. No changes were made to Table 3.3.2 of the GHS between the fifth and seventh revised editions. Furthermore, the GHS (seventh revised edition, 2017, paragraph 3.3.1.1) does not specify "or that is not fully reversible within an observation period of 21 days after that exposure" for the serious eye damage definition. This was retained in the serious eye damage definition in the HPR, from the fifth revised edition of the GHS. This is because a Serious Eye Damage — Category 1 classification may be assigned on the basis of animal test data, that demonstrate effects on the eye in accordance with subsection 8.3.2(1) of the HPR, that are not fully reversible within an observation period of 21 days after exposure.

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of section 8.3.1 of the Hazardous Products Regulations

All data must be considered in a specific order for the purpose of classification in this hazard class. This order applies to the classification of both substances and mixtures. The evaluation steps are listed in order below. More detail on each step is provided in the discussion of section 8.3.2 to section 8.3.7 of the HPR:

1. Positive human data or positive animal data as derived from a study designed to evaluate serious eye damage that meets the classification criteria outlined in subsection 8.3.2(1) are used to classify a substance in Serious Eye Damage — Category 1.
2. Positive human data that meet the classification criteria outlined in subsection 8.3.2(2) are used to classify a substance in Eye Irritation — Category 2.
3. Positive animal data as derived from a study designed to evaluate eye irritation that meet the classification criteria outlined in subsection 8.3.2(3) are used to classify a substance in Eye Irritation — Category 2, with further classification in subcategory 2A or 2B (if possible).
4. Positive human data or positive animal data derived from a study designed to evaluate skin corrosion that meet the classification criteria outlined in subsection 8.3.2(4) (that is, Skin Corrosion — Category 1) are used to classify a substance in Serious Eye Damage — Category 1.
5. Negative human data or negative animal data as derived from a study designed to evaluate serious eye damage or eye irritation is used to determine that a substance does not meet classification criteria for this hazard class. If the conditions outlined in subsection 8.3.2(5) are met, progression to subsequent steps is not required. However, progression through the subsequent steps is necessary if there is no or insufficient negative data available.
6. Positive animal data derived from other eye or skin exposure studies which meet the classification criteria outlined in section 8.3.3 are used to classify a substance in Serious Eye Damage — Category 1, or Eye Irritation — Category 2, with further classification into sub-category 2A or 2B (if possible).
7. Positive in vitro or ex vivo data that meet the classification criteria outlined in subsection 8.3.4(1) or 8.3.4(2) are used to classify a substance in Serious Eye Damage — Category 1, or Eye Irritation — Category 2, with further classification into sub-category 2A or 2B (if possible).
8. Substances with pH extremes (≤2.0 or ≥11.5), as outlined in section 8.3.5, are considered and, if criteria are met, are classified in Serious Eye Damage — Category 1.
9. Positive structure-activity data that meet the criteria outlined in subsection 8.3.6(1) or 8.3.6(2) are used to classify a substance in Serious Eye Damage — Category 1 or Eye Irritation — Category 2, with further classification into sub-category 2A or 2B (if possible).
10. Finally, all the available evidence must be considered together as described in section 8.3.7, to determine if classification in Serious Eye Damage — Category 1, or Eye Irritation — Category 2, with further classification in sub-category 2A or 2B (if possible) is warranted.

If, following step 10, a classification has not been determined, it can be concluded that the substance does not meet the criteria for classification criteria in the Serious Eye Damage/Eye Irritation hazard class.

Figure 30 - Text description

This is a flow diagram that illustrates an evaluation sequence for serious eye damage and eye irritation potential. According to the first step, if positive human data or purposely generated animal data indicate serious eye damage, then classification in Category 1 is the result. For the second step, if human data indicate eye irritation, then classification in Category 2 is the result. For the third step, if purposely generated animal data indicate eye irritation, then classification in Category 2A or 2B is the result. For the fourth step, if the substance is classified in Skin Corrosion – Category 1, then classification in Category 1 is the result.

For the fifth step, if human or purposely generated animal data indicate no serious eye damage or irritation, then the substance is not classified. For the sixth step, if other eye or skin animal data indicate serious eye damage or irritation, then classification in Category 1 or 2, respectively, is the result. For the seventh step, if in vitro or ex vivo data indicate serious eye damage, then classification in Category 1 is the result. For the eighth step, if in vitro or ex vivo data indicate eye irritation, then classification in Category 2 is the result.

For the ninth step, if the pH is less than or equal to 2 or greater than or equal to 11.5, in the absence of alkali/acid reserve effect, then classification in Category 1 is the result. For the 10th step, if SAR indicates serious eye damage, then classification in Category 1 is the result. For the 11th step, if SAR indicates eye irritation, then classification in Category 2 is the result. For the 12th step, if the totality of available data supports a conclusion of serious eye damage or eye irritation, then classification in Category 1 or 2, respectively, is the result. For the last step, if the answer is 'No' to all the previous steps, then the substance cannot be classified.

Discussion of subsection 8.3.2(1) of the Hazardous Products Regulations

Human or animal data demonstrating serious eye damage are considered first. Human data that meet the criteria for serious eye damage results in classification of a substance in Serious Eye Damage — Category 1. Positive human data that are insufficient to meet the criteria for serious eye damage are evaluated again, as follows:

• in the assessment for eye irritation – refer to subsection HPR 8.3.2(2) of the HPR, or
• in the final step of evaluation – refer to section 8.3.7 of the HPR.

Negative results are taken into consideration at a later step – refer to subsection 8.3.2(5) of the HPR.

Animal data must be data from an animal study designed specifically to test serious eye damage and/or eye irritation. Data from other studies that permit observations of eye reactions but are not specifically designed to study serious eye damage and/or eye irritation are considered at later steps – refer to subsection 8.3.2(4) and section 8.3.3 of the HPR.

Serious eye damage includes observation of animals with grade 4 corneal lesions in a study conducted and scored according to OECD TG 405, and other severe reactions (for example, destruction of cornea) observed at any time during the test, as well as persistent corneal opacity, discoloration of the cornea by a dye substance, adhesion, pannus, and interference with the function of the iris or other effects that impair physical vision (GHS, seventh revised edition, 2017, paragraph 3.3.2.1.1).

The criteria for evaluation of effects on the cornea, iris or conjunctiva, based on purposely generated animal data, are reversibility and severity of damage. A positive result meeting the classification criteria in item (1)(b) (i) or (ii) in the Table to subsection 8.3.2(1) of the HPR is required for only 1 of the test animals. This requirement remains true even if more than 1 animal is tested in a study. For example, where 6 rabbits have been tested for eye damage, a positive result in at least 1 animal out of 6 is sufficient for classification of a substance in Serious Eye Damage — Category 1.

The criteria in item 1(c) in the Table to paragraph 8.3.2(1)(c) of the HPR consider animal data that have been assigned scoring values which assess the degree of inflammation. The scoring values are specified in OECD TG 405. Evaluation takes place separately for the cornea and iris. For each test animal, the average scores for 3 consecutive days (24, 48 and 72 hours) are calculated. Where 3 animals have been tested, if 2 of the animals meet or exceed the cut-off value of 3 for corneal opacity and/or exceed the cut-off value of 1.5 for iritis, the substance must be classified in Serious Eye Damage — Category 1. Where more than 3 animals have been tested, scores for each animal are calculated in the same manner as described above and then applied as follows according to the number of animals tested:

• 6 rabbits tests: mean score of ≥ 3 for corneal opacity and/or > 1.5 for iritis in at least 4 out of 6 animals
• 5 rabbits tests: mean score of ≥ 3 for corneal opacity and/or > 1.5 for iritis in at least 3 out of 5 animals
• 4 rabbits tests: mean score of ≥ 3 for corneal opacity and/or > 1.5 for iritis in at least 3 out of 4 animals (GHS, seventh revised edition, 2017, paragraphs 3.3.5.3.3 to 3.3.5.3.5).

As with human data, negative results from purposely generated animal studies are taken into consideration at a later step – refer to subsection 8.3.2(5) of the HPR.

Discussion of subsection 8.3.2(2) of the Hazardous Products Regulations

When human data is available but insufficient to meet the classification criteria for serious eye damage, the data must also be evaluated for eye irritation.

Discussion of subsection 8.3.2(3) of the Hazardous Products Regulations

When purposely generated animal data is available but insufficient to meet classification criteria for serious eye damage, the data must also be evaluated for eye irritation.

Animal data must be derived from "purposely generated animal data", which means that the data is from an animal study designed specifically to test serious eye damage and/or irritation. Data from other studies that permit observations of eye reactions but are not specifically designed to study serious eye damage and/or eye irritation must be considered at later steps – refer to subsection 8.3.2(4) and section 8.3.3 of the HPR. Only positive results from purposely generated animal data are considered in this step. Negative results are taken into consideration at a later step - refer to subsection 8.3.2(5) of the HPR.

Eye Irritation — Category 2 has 2 sub-categories: 2A, and 2B. If the data do not permit sub- categorization, the substance would simply be classified in Category 2 without further sub- categorization.

The criteria for evaluation of effects on the cornea, iris or conjunctiva, based on purposely generated animal data, are reversibility and severity of damage. Irreversible effects indicate serious eye damage and classification must be in Serious Eye Damage — Category 1. In the case of eye irritation, the effects must be reversible. The rate at which reversibility occurs is what differentiates the 2 sub-categories.

The criteria in subsection 8.3.2(3) of the HPR consider animal data that have been assigned scoring values that assess the degree of inflammation, according to OECD TG 405. Evaluation takes place separately for the cornea, iris, conjunctival redness (erythema) and conjunctival edema (chemosis or swelling). For each test animal, the average scores for 3 consecutive days (24, 48 and 72 hours) are calculated. Where 3 animals have been tested, if 2 of the animals meet or exceed the cut-off value of 1 for corneal opacity and/or 1 for iritis and/or 2 for conjunctival redness and/or 2 for conjunctival edema, the substance must be classified in Eye Irritation — Category 2.

Where more than 3 animals have been tested, scores for each animal are calculated in the same manner as described above, and applied according to the number of animals tested, as follows:

• 6 rabbits tests: mean score of ≥ 1 for corneal opacity and/or ≥ 1 for iritis and/or ≥ 2 for conjunctival redness and/or ≥ 2 for conjunctival edema in at least 4 out of 6 animals
• 5 rabbits tests: mean score of ≥ 1 for corneal opacity and/or ≥ 1 for iritis and/or ≥ 2 for conjunctival redness and/or ≥ 2 for conjunctival edema in at least 3 out of 5 animals
• 4 rabbits tests: mean score of ≥ 1 for corneal opacity and/or ≥ 1 for iritis and/or ≥ 2 for conjunctival redness and/or ≥ 2 for conjunctival edema in at least 3 out of 4 animals (GHS, seventh revised edition, 2017, paragraphs 3.3.5.3.3 to 3.3.5.3.5)

If the effects listed above fully reverse between seven and 21 days, classification in Eye Irritation — Category 2A is appropriate. If the above effects fully reverse within seven days, then classification in Eye Irritation — Category 2B is appropriate. If the above effects fully reverse within 21 days and it is not possible to subcategorize further, Eye Irritation — Category 2 is assigned.

Discussion of subsection 8.3.2(4) of the Hazardous Products Regulations

Testing for serious eye damage is often not carried out on substances known or predicted to be corrosive to the skin. Such substances are automatically considered to be seriously damaging to the eye. Therefore, if criteria for skin corrosion are met, as per subsection 8.2.2(1) or 8.2.2(2) of the HPR, the substance is also classified in Serious Eye Damage — Category 1.

This cross-over classification is only allowed if the basis for classification for Skin Corrosion is either human data or purposely generated animal data. Other types of animal data on skin exposure are not considered here, but are considered in section 8.3.3.

Discussion of subsection 8.3.2(5) of the Hazardous Products Regulations

In this step, negative human data or negative animal data derived from a serious eye damage and/or eye irritation study can be used to determine that the substance does not cause serious eye damage or eye irritation.

In the case of a purposely-generated animal study, at least 3 test animals have to be assessed and all the conditions of subsection 8.3.2(5) must be met in order to conclude that the substance does not cause serious eye damage or eye irritation.

If all the conditions of subsection 8.3.2(5) of the HPR are met, the substance can be considered as not classified under this hazard class and there is no requirement to progress further in the evaluation process. However, progression through the subsequent steps is necessary if no data or insufficient negative data are available.

Discussion of section 8.3.3 of the Hazardous Products Regulations

Animal data from studies other than those specifically designed to test for serious eye damage and/or eye irritation must be evaluated if it has not been conclusively established that the substance does not cause serious eye damage or eye irritation according to subsection 8.3.2(5) of the HPR. These data include, for example, skin studies other than those purposely generated for skin irritation and/or skin corrosion (refer to discussion of section 8.2.3 of the HPR) and other eye exposure studies, which permit observation of eye reactions. Only positive results from such studies are considered for the classification of the substance.

Discussion of subsection 8.3.4(1) and 8.3.4(2) of the Hazardous Products Regulations

Once in vivo human and animal data have been evaluated, in vitro and/or ex vivo data must be evaluated for serious eye damage and eye irritation. Only positive results can be considered for classification at this step.

Examples of scientifically validated test methods for Serious Eye Damage — Category 1 include:

• OECD TG 437 – Bovine Corneal Opacity and Permeability Test Method: Using isolated bovine cornea, classification of the test substance in Serious Eye Damage — Category 1 is met on the basis of an in vitro irritancy score (IVIS) or a laserlight-based opacitometer (LLBO) irritancy score (LIS) depending on the equipment used. Table 8.10 below summarizes how the classification criteria apply.

Table 8.10 Application of classification criteria for OECD TG 437 data.

Opacitometer	Criteria	Classification
Opacitometer 1 (OP-KIT)	IVIS > 55	Category 1
Opacitometer 2 (LLBO)	LIS > 30 and lux/7 ≤ 145 and OD490 > 2.5 or LIS > 30 and lux/7 > 145	Category 1

• OECD TG 438 – Isolated Chicken Eye (ICE) Test Method: Using enucleated chicken eyes, corneal swelling, opacity and fluorescein retention are measured and each assigned an ICE class. Classification of the test substance in Serious Eye Damage — Category 1 is met if 1 or more of the following requirements are satisfied:
  • All 3 endpoints are ICE Class IV
  • 2 endpoints are ICE Class IV and the other is ICE Class III
  • 2 endpoints are ICE Class IV and the other is ICE Class II
  • 2 endpoints are ICE Class IV and the other is ICE Class I
  • Corneal opacity ≥3 at 30 minutes in at least 2 eyes
  • Corneal opacity = 4 at any time point in at least 2 eyes
  • Severe loosening of the epithelium in at least 1 eye
• OECD TG 460 – Flourescein Leakage Test Method: Using cells, the amount of fluorescein leakage is measured following a defined exposure period. Classification of the test substance in Serious Eye Damage — Category 1 is met if the chemical concentration causing 20% fluorescein leakage (FL20) is ≤ 100 mg/mL.
• OECD TG 491 –Short Time Exposure Test Method: Using cells, the viability of the cells is measured following a 5-minute exposure period. Classification of the test substance in Serious Eye Damage — Category 1 is met if the cell viability is ≤ 70% following exposure to the substance at a 5% and 0.05% concentration.
• OECD TG 496 – in vitro Macromolecular Test Method: Using a macromolecular matrix that mimics the structure of the transparent cornea, damage to the matrix is measured by changes in light scattering. Classification of the test substance in Serious Eye Damage — Category 1 is met when the Maximum Qualified Score (MQS) is > 30.0.

Note: At the time of writing this guidance, there are no validated and internationally accepted in vitro test methods available for assessing eye irritation. In vitro and ex vivo data can only be used for classification when the tested substance is within the applicability domain of the test method(s) used.

(Details on test methods from website: OECD Guidelines for Testing of Chemicals, Section 4 – Health Effects)

Discussion of section 8.3.5 of the Hazardous Products Regulations

A pH of ≤2.0 or ≥11.5 for a substance is sufficient to trigger its classification in Serious Eye Damage — Category 1 under section 8.3.5 of the HPR, unless data available from an assessment of alkali or acid reserve supports the conclusion that the substance need not be classified based on its pH. The alkali or acid reserve is a measure of the buffering capacity of substances. In general, the higher the buffering capacity, the higher the potential for serious eye damage.

Note: At the time of writing this guidance, there is no validated and internationally accepted method for assessing alkali or acid reserve (buffering capacity).

If the pH of a substance is ≤ 2.0 or ≥ 11.5 but an assessment of alkali or acid reserve supports the conclusion that the substance need not be classified based on its pH, it is necessary to proceed to the next step in the classification procedure (section 8.3.6 of the HPR).

If the pH of a substance is > 2.0 or < 11.5, it is necessary to proceed to the next step in the classification procedure (section 8.3.6 of the HPR).

Discussion of subsections 8.3.6(1) and 8.3.6(2) of the Hazardous Products Regulations

If none of the criteria in sections 8.3.2 through 8.3.5 of the HPR have been met, then a structure-activity relationship (SAR) must be considered as potential evidence in support of classification. The SAR can be used to conclude that the substance causes serious eye damage or is an eye irritant, but cannot be used to conclude that the substance does not cause serious damage to the eye or is not an eye irritant.

Discussion of section 8.3.7 of the Hazardous Products Regulations

As a final step in determining classification of a substance in this hazard class, all available information must be considered. Evidence that, at some or all of the previous steps in the evaluation, were insufficient to lead to classification must be considered together. If, when considered together, the evidence warrants the classification of the substance as causing serious eye damage or eye irritation, the substance must be classified accordingly.

If, following this evaluation, it is determined that there is insufficient data to support classification of a substance for serious eye damage or eye irritation, the substance is not classified in this hazard class.

Classification in a Category or Subcategory of the Class

Classification of Mixtures

Discussion of section 8.3.8 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for serious eye damage or eye irritation, which means that the procedures described in sections 8.3.9 to 8.3.11 must be followed in the order in which these sections appear in the HPR. As specified in subsection 8.3.9(1), if there are test data for the mixture as a whole, these data may be used to classify the mixture, unless, according to subsection 8.3.2(5), the mixture need not be classified. As specified in subsection 8.3.9(2), if test data are available for the mixture as a whole, but the mixture cannot be classified, then the procedures described in sections 8.3.10 and 8.3.11 must be followed.

Section 8.3.10 specifies which bridging principles may be applied to this hazard class. Finally, according to section 8.3.11, if there are no test data available for the mixture as a whole and bridging principles cannot be applied, then the classification of mixtures for serious eye damage or eye irritation is based on the evaluation of available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified in this hazard class.

Discussion of subsection 8.3.9(1) of the Hazardous Products Regulations

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to in subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is the same as for substances, and is carried out in accordance with sections 8.3.2 to 8.3.7 of the HPR. Therefore, the discussion corresponding to these sections and the discussion corresponding to Part 2 of the HPR are relevant to the classification of mixtures if there are data available for the mixture as a whole.

If data meet the criteria found in sections 8.3.2 through 8.3.7 of the HPR, then the mixture must be classified within the category whose criteria are met.

For example, if there are no human, animal or in vitro/ex vivo test data available for the mixture as a whole, however, the pH of the mixture can be measured and meets the criteria outlined in section 8.3.5 (pH ≤2.0 or ≥11.5), the mixture must be classified in Serious Eye Damage — Category 1. Evaluation on the mixture can stop at this point and there is no need to assess bridging principles or evaluate information available on individual ingredients of the mixture (sections 8.3.10 and section 8.3.11 of the HPR).

Likewise, if there are data on the mixture as a whole that meet the conditions of subsection 8.3.2(5) of the HPR (i.e., human or purposely generated animal data indicating that the tested substance does not cause serious eye damage or eye irritation), then there is no requirement to progress further in the evaluation process for this endpoint. The mixture is not classified in this hazard class.

With regard to section 8.3.4 of the HPR, it is important to note that in vitro and ex vivo data generated from validated test methods may not have been validated using mixtures. Although these methods are considered broadly applicable to mixtures, they can only be used for classification of mixtures when all ingredients of the mixture fall within the applicability domain of the test methods used.

Discussion of subsection 8.3.9(2) of the Hazardous Products Regulations

If, following the evaluation process outlined in subsection 8.3.9(1) of the HPR, the mixture as a whole cannot be classified and the mixture cannot be excluded from classification based on applicable negative data (subsection 8.3.2(5)), then the classification must proceed through, in order, sections 8.3.10 and 8.3.11 of the HPR.

Discussion of section 8.3.10 of the Hazardous Products Regulations

Section 8.3.10 of the HPR describes the second step in the tiered approach for the classification of mixtures for serious eye damage/eye irritation.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

All of the bridging principles are applicable to the Serious Eye Damage/Eye Irritation hazard class, namely: dilution, production batches, increase in concentration of hazardous ingredient, interpolation, substantially similar mixtures, and aerosols.

If the bridging principles cannot be applied to classify as Serious Eye Damage — Category 1 or Eye Irritation — Category 2, then it is necessary to proceed to the third step in the tiered approach for the classification of mixtures.

Discussion of subsection 8.3.11(1) of the Hazardous Products Regulations

If a classification for the mixture has not been determined following the application of sections 8.3.9 and 8.3.10 of the HPR, then data available for the ingredients of the mixture must be considered as the final step in the tiered approach for the classification of mixtures in this hazard class.

Application of this section considers as "relevant ingredients", ingredients that are present in concentrations at or above 1.0% (w/w for solids, liquids, dusts, mists and vapours and v/v for gases) unless there is an indication that an ingredient present at < 1% has serious eye damaging or eye irritant properties at that concentration. Paragraph 8.3.11(1)(b) builds on the concept found in subsection 2.5(1) of the HPR, where it is stated that the mixture is classified based on ingredients present below the concentration limit that still present the hazard of the hazard class. These ingredients must be considered as part of the additivity approach to determine the classification of the mixture.

The concentrations of all relevant ingredients are summed according to the rules outlined in subsection 8.3.11(2), unless the mixture contains ingredients for which the additivity approach cannot be applied. The approach for mixtures with 1 or more particular ingredients for which the additivity approach does not apply is discussed in subsection 8.3.11(3).

Discussion of subsection 8.3.11(2) of the Hazardous Products Regulations

The order of precedence for applying additivity is from paragraphs 8.3.11(2)(a) through 8.3.11(2)(d) of the HPR. For this subsection, what is considered a "relevant ingredient" is identified in paragraphs 8.2.11(1)(a) and (b) and 8.3.11(1)(a) and (b) of the HPR.

If the sum of all relevant ingredients classified in Serious Eye Damage — Category 1 and Skin Corrosion — Category 1, 1A, 1B and 1C totals 3.0% or more, the mixture is classified in Serious Eye Damage — Category 1.

If the sum of all relevant ingredients classified in Serious Eye Damage — Category 1 and Skin Corrosion — Category 1, 1A, 1B and 1C is ≥ 1.0% but < 3.0%, the mixture is classified in Eye Irritation — Category 2.

If the mixture contains relevant Eye Irritation — Category 2 ingredients, the concentrations of those ingredients are summed, and if the sum is 10.0% or more, the mixture is classified in Eye Irritation — Category 2.

If the sum of all relevant ingredients classified in Eye Irritation — Category 2A totals 10.0% or more, and there are no ingredients classified in Category 2 or subcategory 2B, the mixture is classified in Eye Irritation — Category 2 or the subcategory Eye Irritation — Category 2A.

If the sum of all relevant ingredients classified in Eye Irritation — Category 2B totals 10.0% or more, and there are no ingredients classified in Category 2 or subcategory 2A, the mixture is classified in Eye Irritation — Category 2 or the subcategory Eye Irritation — Category 2B.

If the sum of all relevant ingredients classified in 2 or more of the following categories or subcategories is equal to or greater than 10.0%, the mixture is classified in the category "Eye Irritation ─ Category 2":

• Eye Irritation — Category 2
• Eye Irritation — Category 2A
• Eye Irritation — Category 2B

If the mixture contains relevant ingredients classified in Skin Corrosion ─ Category 1, 1A, 1B or 1C and Serious Eye Damage ─ Category 1 and relevant ingredients classified in Eye Irritation ─ Category 2, 2A or 2B, a weighting factor of 10 is applied to the sum of the Category 1 ingredients. 10 times the sum of concentrations for Category 1, 1A, 1B and 1C ingredients added to the concentration sum of Category 2, 2A and 2B ingredients must total 10.0% or more for the mixture to be classified in Eye Irritation ─ Category 2.

Table 8.11 Concentration of ingredients of a mixture that triggers classification in the Serious Eye Damage ─ Category 1 or Eye Irritation ─ Category 2, 2A or 2B hazard class.

Sum of ingredients classified in	Concentration triggering classification of a mixture in:
	Serious Eye Damage	Eye Irritation	Eye Irritation	Eye Irritation
	Category 1	Category 2	Category 2A	Category 2B
Skin Corrosion — Category 1+ Serious Eye Damage — Category 1 (Footnote 1)	≥ 3%	≥ 1% but < 3%	-	-
Eye Irritation — Category 2	-	≥ 10%	-	-
Two or more of the categories Eye Irritation — Category 2, 2A and 2B	-	≥ 10%	-	-
Eye Irritation 2A	-	-	≥ 10%Footnote 2
Eye Irritation 2B	-	-	-	≥ 10%Footnote 3
10 x (Skin Corrosion — Category 1, 1A, 1B and 1C + Serious Eye Damage — Category 1)Footnote 1 + Eye Irritation — Category 2, 2A and 2B	-	≥ 10%	-	-
1 If an ingredient is classified in both Skin Corrosion ─ Category 1 and Serious Eye Damage ─ Category 1, its concentration is considered only once in the calculation. Return to footnote 1 referrer 2 If the sum of ingredients classified in Eye Irritation ─ Category 2A ≥ 10% and there are no ingredients classified in the category Eye Irritation — Category 2 or the subcategory Eye Irritation — Category 2B, the mixture is classified as Eye Irritation ─ Category 2A or Eye Irritation ─ Category 2. Return to footnote 2 referrer 3 If the sum of ingredients classified in Eye Irritation ─ Category 2B ≥ 10% and there are no ingredients classified in the category Eye Irritation — Category 2 or the subcategory Eye Irritation — Category 2A, the mixture is classified as Eye Irritation ─ Category 2B or Eye Irritation ─ Category 2. Return to footnote 3 referrer

(Skin Corrosion — Category 1, Serious Eye Damage — Category 1 and Eye Irritation — Category 2 based on GHS, seventh revised edition, 2017, Table 3.3.3)

Discussion of subsection 8.3.11(3) of the Hazardous Products Regulations

The additivity approach explained in subsection 8.3.11(2) of the HPR might not apply for certain types of substances such as acids and bases, inorganic salts, aldehydes, phenols, and surfactants given that many such substances could cause serious eye damage or eye irritation at concentrations less than those established for the additivity approach.

Therefore, subsection 8.3.11(3) specifies that a mixture must be classified in Serious Eye Damage — Category 1 or Eye Irritation — Category 2 based on a single ingredient of the types indicated in Column 2 of the Table to subsection 8.3.11(3) that exceeds the concentration limits listed in Column 3 of the same table. Please note that Column 2 of Item 4 states "Other ingredients classified in the category "Eye Irritation — Category 2"", which includes ingredients classified in the categories "Eye Irritation — Category 2A" and "Eye Irritation — Category 2B".

Hazard Communication

The required symbols, signal words, hazard statement, and precautionary statements for Serious Eye Damage — Category 1 and Eye Irritation — Category 2 are specified in Section 3 of Annex 3 of the GHS (seventh revised edition, 2017, pp. 350-351), subject to paragraphs 3(5)(h), (i) and (j) of the HPR. These paragraphs specify that if the hazardous product is classified in:

• Serious Eye Damage — Category 1, the information elements specified in the GHS for Eye Damage/Irritation — Category 1 apply
• Eye Irritation — Category 2, the information elements specified in the GHS for Eye Damage/ Irritation — Category 2A apply and
• Eye Irritation — Category 2A or 2B, the information elements specified, respectively, in the GHS for Eye Damage/Irritation — Category 2A or 2B apply

Note: Substances classified in Skin Corrosion — Category 1 do not also have to be labelled for Serious Eye Damage — Category 1, even if they meet the criteria for classification in that category, because:

1. according to subsection 3.6(2), if there is a requirement to provide the hazard statement "Causes severe skin burns and eye damage" any requirement to provide the hazard statement "Causes serious eye damage" does not apply;
2. the required signal word and symbol are the same for both hazard classes; and
3. the precautionary statements for Skin Corrosion — Category 1 include the precautionary statements for Serious Eye Damage — Category 1.

Classification of Serious Eye Damage/Eye Irritation for Substances Examples

Example 8.3.1: Standard OECD TG 405 with 3 test animals (ECHA Guidance, 2017, pp. 324-326)

Available data

1. Human data: not available
2. Animal data: Serious eye damage was not observed.

The scoring results following application are:

Table 8.12 Standard OECD TG 405 test scoring results for cornea on 3 rabbits following application.

Rabbit No.	Cornea:
	1h	24h	48h	72h	21d
1	0	2	2	2	0
2	2	2	2	2	0
3	2	2	1	1	0

Table 8.13 Standard OECD TG 405 test scoring results for iris on 3 rabbits following application.

Rabbit No.	Iris:
	1h	24h	48h	72h	21d
1	0	1	1	1	0
2	1	1	1	1	0
3	1	1	1	1	0

Table 8.14 Standard OECD TG 405 test scoring results for conjunctival erythema (redness) on 3 rabbits following application.

Rabbit No.	Conjunctival Erythema (Redness)
	1h	24h	48h	72h	21d
1	2	2	2	2	0
2	1	1	1	1	0
3	1	1	1	1	0

Table 8.15 Standard OECD TG 405 test scoring results for conjunctival edema (chemosis or swelling) on 3 rabbits following application.

Rabbit No.	Conjunctival Edema (Chemosis or Swelling)
	1h	24h	48h	72h	21d
1	0	3	3	3	0
2	2	2	2	1	0
3	2	3	2	2	0

Classification

Eye Irritation — Category 2

Rationale

All effects were reversible within 21 days. The mean scores for cornea, iris, conjunctival erythema and conjunctival edema for each rabbit over the time periods 24, 48 and 72 hours are, respectively:

• Rabbit 1= 2, 1, 2 and 3
• Rabbit 2 = 2, 1, 1 and 1.7
• Rabbit 3 = 1.3, 1, 1 and 2.3

At least 2 of the 3 rabbits meet or exceed the cut-off scores specified in the Table to subsection 8.3.2(3) of the HPR:

• 2 for cornea (2/3 rabbits)
• 1 for iris (3/3 rabbits), and
• 2 for conjunctival edema (2/3 rabbits)

Example 8.3.2: Test with more than 3 test animals (ECHA Guidance, 2017, pp. 326-328)

Available data

1. Human data: not available
2. Animal data: The scoring results following application are:

Table 8.16 Test scoring results for cornea on 4 rabbits following application.

Rabbit No.	Cornea:
	1h	24h	48h	72h	7d	14d	21d
1	1	2	3	3	1	1	0
2	1	2	2	3	1	1	0
3	1	2	3	3	2	1	0
4	1	2	4	4	2	1	0

Table 8.17 Test scoring results for iris on 4 rabbits following application.

Rabbit No.	Iris:
	1h	24h	48h	72h	7d	14d	21d
1	0	0	0	0	0	0	0
2	0	0	0	0	0	0	0
3	0	1	1	1	1	0	0
4	0	0	0	0	0	0	0

Table 8.18 Test scoring results for conjunctival erythema (redness) on 4 rabbits following application.

Rabbit No.	Conjunctival Erythema (Redness)
	1h	24h	48h	72h	7d	14d	21d
1	2	2	2	1	1	1	0
2	2	2	2	1	1	0	0
3	2	2	2	1	1	1	1
4	2	2	2	1	0	0	0

Table 8.19 Test scoring results for conjunctival edema (chemosis or swelling) on 4 rabbits following application.

Rabbit No.	Conjunctival Edema (Chemosis or Swelling):
	1h	24h	48h	72h	7d	14d	21d
1	2	2	2	1	1	1	0
2	2	2	1	1	1	0	0
3	2	2	2	1	1	1	1
4	2	2	2	1	1	1	1

Classification

Serious Eye Damage — Category 1

Rationale

Effects in conjunctiva are not reversible at 21 days. Animal #4 had maximum cornea score 4/4 at 48 and 72 hours.

Classification of Serious Eye Damage/Eye Irritation for Mixtures Example

Example 8.3.3: Classification based on the classified ingredients

Available data

Data for the mixture as a whole is not available other than the pH which was measured as 9.0-10.0. There is insufficient information available to apply the bridging principles. Therefore, classification is based on the classified ingredients.

Table 8.20 Classification of serious eye damage/eye irritation for mixtures based on the classified ingredients.

Ingredient	Classification	Concentration (%w/w)
Substance A	Serious Eye Damage — Category 1	1.8
Substance B	Eye Irritation — Category 2	0.5
Substance C	Serious Eye Damage — Category 1	5.4
Substance D	Not classified	4.0
Substance E	Not classified	2.0
Water	Not classified	86.3

Classification

Serious Eye Damage — Category 1

Rationale

1. The pH of the mixture does not meet the criteria specified in section 8.3.5 of the HPR.
2. Substance D, Substance E and water can be disregarded as they are not classified for Serious Eye Damage/Eye Irritation or for Skin Corrosion.
3. The mixture contains 7.2% (1.8% + 5.4%) Serious Eye Damage — Category 1 ingredients. This value exceeds the 3.0% cut-off established in paragraph 8.3.11(2)(a) of the HPR.

Subpart 4 Respiratory or Skin Sensitization

Discussion

Sensitization is a response whereby a person or test animal is exposed to a substance that at first causes no or little immune reaction but which, upon repeated exposure, induces an immune response that is often stronger and not necessarily limited to the contact site.

Sensitization includes 2 phases: induction of specialized immunological memory by exposure to an allergen, followed by elicitation, that is, the production of a cell-mediated or antibody-mediated allergic response to that allergen. Usually lower levels of the allergen are necessary for elicitation than are required for induction.

A substance or mixture can be classified as follows:

1. Respiratory Sensitizer — Category 1
2. Skin Sensitizer — Category 1 or
3. both, Respiratory Sensitizer — Category 1 and Skin Sensitizer — Category 1

Symptoms of skin sensitization include erythema (reddening of the skin), blisters, fissures in tissue and fluid discharge. Sensitization differs from skin irritation or corrosion, which do not involve an allergic response.

Respiratory sensitization is normally seen as asthma but other hypersensitivity reactions such as rhinitis/conjunctivitis and alveolitis are also considered. The condition will have the clinical character of an allergic reaction; however, immunological mechanisms do not have to be demonstrated.

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of subsection 8.4.1(1) of the Hazardous Products Regulations

At present, classification in Respiratory Sensitizer — Category 1 is based on human data because there currently are no recognized and validated animal models available for the testing of respiratory hypersensitivity. The mouse Immunoglobulin E (IgE) test and guinea pig models are potentially useful but have not been fully standardized. The guinea pig respiratory parameter tests are reported to be poorly reproducible and are confounded by irritant effects of the test substance.

Human evidence of respiratory hypersensitivity could be (GHS seventh revised edition, 2017, paragraphs 3.4.2.1.2.3 and 3.4.2.1.2.5):

1. clinical history and data from appropriate lung function tests related to exposure to the substance, confirmed by other supportive evidence which may include:
   1. in vivo immunological test (e.g., skin prick test);
   2. in vitro immunological test (e.g., serological analysis);
   3. studies that may indicate other specific hypersensitivity reactions where immunological mechanisms of action have not been proven (e.g., repeated low-level irritation, pharmacologically mediated effects);
   4. a chemical structure related to substances known to cause respiratory hypersensitivity;
2. positive data from bronchial challenge tests with the substance conducted according to accepted guidelines for the determination of a specific hypersensitivity reaction. A positive bronchial challenge test is generally considered to be the gold standard for the identification of a respiratory sensitizer and can provide sufficient evidence on its own, but in practice many of the other examinations will already have been carried out. The test should be conducted with a sub-irritant concentration of the allergen, it should maintain blind conditions to the nature of the exposure, and account for possible confounding factors such as the use of asthma medication, smoking habits, and the existence of upper respiratory tract infections (for example, tuberculosis). A positive response needs to be of appropriate magnitude (for example, a decrease in the forced expiratory volume in 1 second of 15% or greater over and above the effect seen at the control challenge).

Clinical history should include both medical and occupational history to determine a relationship between exposure to a specific substance and the development of respiratory sensitization (GHS seventh revised edition, 2017, paragraph 3.4.2.1.2.4). Understanding the type and pattern of symptoms is helpful. For example, respiratory symptoms may occur during the working week and increase in severity as the week progresses, but improve during absences from work. Medical history should include a note of other allergic or airway disorders from childhood, and smoking history.

In addition to evidence such as that listed above, it is also necessary to consider the size of the population exposed and the extent of exposure.

The mechanisms by which substances induce symptoms of asthma are not yet fully known. As a precaution, substances that induce symptoms of asthma are considered respiratory sensitizers. However, if on the basis of the evidence, it can be demonstrated that these substances induce symptoms of asthma by irritation only in people with bronchial hyperreactivity, they should not be considered as respiratory sensitizers (GHS seventh revised edition, 2017, footnote 2 to paragraph 3.4.2.1.3).

Discussion of subsection 8.4.1(2) of the Hazardous Products Regulations

If sufficient data are available, Category 1 respiratory sensitizers must be further divided into Respiratory Sensitizer — Category 1A or 1B. Category 1A substances demonstrate a high frequency of respiratory sensitization whereas Category 1B substances demonstrate a low to moderate frequency of respiratory sensitization. A substance must not be classified in Category 1B unless Category 1A can be excluded.

There is no quantification of "high" or "low to moderate" as these terms are used here. A scientifically defensible conclusion must be reached by conducting a thorough evaluation of all relevant data.

Discussion of subsection 8.4.1(3) of the Hazardous Products Regulations

Skin Sensitizer — Category 1 is based on human or test animal data. Human evidence can be based on positive data from:

• patch testing such as the Human Repeat Insult Patch Test (HRIPT) or Human Maximization Test (HMT)
• diagnostic patch testing from clinical data
• epidemiological studies showing allergic contact dermatitis and/or
• positive data from experimental studies in humans

For Skin Sensitizer — Category 1 classification based on animal studies, examples of scientifically validated methods include:

• OECD TG 406 – This test guideline describes the Guinea Pig Maximization test and the Buehler guinea pig test.

The Guinea Pig Maximization test (GPMT) uses an adjuvant to potentiate sensitization. Elicitation reactions are measured in previously sensitized animals. A minimum of 10 test animals and 5 control animals is needed. A response of at least 30% of the animals is considered positive.

The Buehler guinea pig test does not use an adjuvant. Elicitation reactions are measured in previously sensitized animals. A minimum of 20 test animals and 10 control animals is needed. A response of at least 15% of the animals is considered positive.

• OECD TG 429 - Local Lymph Node Assay (LLNA): Conducted in the mouse, the LLNA measures lymphocyte proliferation in the lymph nodes draining the site of test substance application. This proliferation is proportional to the dose and to the potency of the applied allergen and provides a simple means of obtaining a quantitative measurement of sensitization. Responses provoked during the induction of sensitization are measured.

A stimulation index of 3 or more is considered a positive response in the LLNA (OECD TG 429). The LLNA has 2 additional variations:

• OECD TG 442A: LLNA: DA
  • A stimulation index of 1.8 or more is considered a positive response
• OECD TG 442B: LLNA: BrdU-ELISA
  • A stimulation index of 1.6 or more is considered a positive response

The Mouse Ear Swelling Test (MEST) appears to be a reliable screening test to detect moderate to strong sensitizers, and can be used as a first stage in the assessment of skin sensitization potential (GHS seventh revised edition, 2017, paragraph 3.4.2.2.3.1). Other methods may be used provided that they are scientifically validated methods.

Note: For both animal and human data, consideration should also be given to the impact of solvent(s). The solvent(s) should not interfere or bias the test results. OECD TG 406 and 429 provide guidance on the selection and suitability of solvent(s).

For classification of a substance in Skin Sensitizer — Category 1, evidence could include any or all of the following:

• Positive data from patch testing, normally obtained from more than 1 dermatology clinic;
• Epidemiological studies showing allergic contact dermatitis caused by the substance. Situations in which a high proportion of those exposed exhibit characteristic symptoms are to be looked at with special concern, even if the number of cases is small;
• Positive data from appropriate animal studies;
• Positive data from experimental studies in humans;
• Well documented episodes of allergic contact dermatitis, normally obtained from more than 1 dermatology clinic; and
• Severity of reaction may also be considered (GHS seventh revised edition, 2017, paragraph 3.4.2.2.4.1).

Evidence from animal studies is usually much more reliable than evidence from human exposure. However, in cases where evidence is available from both animal and human sources, and there is conflict between the results, the quality and reliability of the evidence from both sources must be assessed to resolve the question of classification on a case-by-case basis. Normally, human data are not generated in controlled experiments with volunteers, but rather are usually derived from case-control or other less defined studies. Evaluation of human data must therefore be carried out with caution and consider factors such as the inherent properties of the substance, exposure situation, bioavailability, individual predisposition and preventive measures taken. Negative human data should not normally be used to negate positive results from animal studies. (GHS seventh revised edition, 2017, paragraph 3.4.2.2.4.2).

If none of the above-mentioned conditions are met, the substance need not be classified as a skin sensitizer. However, before this decision is finalized, a combination of 2 or more indicators of skin sensitization as listed below must be considered on a case-by-case basis.

• Isolated episodes of allergic contact dermatitis;
• Epidemiological studies of limited power, e.g., where chance, bias or confounders have not been ruled out fully with reasonable confidence;
• Data from animal tests, performed according to existing guidelines, which do not meet the criteria for a positive result described in paragraph 3.4.2.2.3 of the GHS, but which are sufficiently close to the limit to be considered significant;
• Positive data from non-standard methods;
• Positive results from close structural analogues.

(GHS seventh revised edition, 2017, paragraph 3.4.2.2.4.3)

Immunological contact urticaria

Substances which cause immunological contact urticaria with or without meeting the criteria for respiratory sensitizers shall be considered for classification as skin sensitizers. There is no recognized animal model available to identify substances which cause immunological contact urticaria. Therefore, classification will normally be based on human evidence, which will be similar to that for skin sensitization.

Discussion of subsection 8.4.1(4) of the Hazardous Products Regulations

If sufficient data are available, Category 1 skin sensitizers must be further classified into Skin Sensitizer — Category 1A or 1B. Category 1A substances demonstrate a high frequency of skin sensitization whereas Category 1B substances demonstrate a low to moderate frequency of skin sensitization. A substance must not be classified in Category 1B unless Category 1A can be excluded.

There is no quantification of "high" or "low to moderate" as these terms are used here. A scientifically defensible conclusion must be reached by conducting a thorough evaluation of all relevant data.

Tables 8.21 and 8.22 below can be used to differentiate between classification in Skin Sensitizer – Category 1A and 1B based on human and animal data.

Table 8.21 Human Evidence for Category 1A and 1B (GHS seventh revised edition, 2017, paragraph 3.4.2.2.2.1 and 3.4.2.2.2.2).

Human Data	Category 1A Criteria	Category 1B Criteria
Human Repeat Insult Patch Test (HRIPT), Human Maximization Test (HMT) - Induction threshold	positive responses at ≤ 500 μg/cm2	positive responses at > 500 μg/cm2
Diagnostic Patch Test Data	relatively high and substantial incidence of reactions in a defined population in relation to relatively low exposure	relatively low but substantial incidence of reactions in a defined population in relation to relatively high exposure
Other Epidemiological Evidence	relatively high and substantial incidence of allergic contact dermatitis in relation to relatively low exposure.	relatively low but substantial incidence of allergic contact dermatitis in relation to relatively high exposure

Table 8.22 Animal Evidence for Category 1A and 1B (GHS seventh revised edition, 2017, tables 3.4.3 and 3.4.4).

Assay	Category 1A Criteria	Category 1B Criteria
Local Lymph Node Assay (LLNA) (OECD TG 429)	EC3* value ≤ 2%	EC3* value > 2%
Guinea Pig Maximization Test (GPMT)	≥ 30% responding at ≤ 0.1% intradermal induction dose or ≥ 60% responding at > 0.1% to ≤ 1% intradermal induction dose	≥ 30% to < 60% responding at > 0.1% to ≤ 1% intradermal induction dose or ≥ 30% responding at > 1% intradermal induction dose
Buehler Assay	≥15% responding at ≤ 0.2% topical induction dose or ≥ 60% responding at > 0.2% to ≤ 20% topical induction dose	≥ 15% to < 60% responding at > 0.2% to ≤ 20% topical induction dose or ≥ 15% responding at > 20% topical induction dose

*EC3 is the estimated concentration needed to produce a stimulation index of 3

Classification of Mixtures

Discussion of section 8.4.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for respiratory or skin sensitization, which means that the procedures described in sections 8.4.3 to 8.4.5 must be followed in the order in which these sections appear in the HPR.

As with a substance, the mixture may be classified as a respiratory or skin sensitizer, or both. Therefore, progression through the order of provisions is required for each endpoint. For example, if, based on test data on the mixture as a whole, the supplier is able to classify the mixture for skin sensitization, there is no need to assess bridging principles or data for the ingredients for this endpoint. However, if data on the mixture as a whole is not available for respiratory sensitization, progression to bridging principles and then to ingredient data is required to classify the mixture with regard to respiratory sensitization, as applicable.

Discussion of section 8.4.3 of the Hazardous Products Regulations

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is exactly the same as for substances, and is carried out according to section 8.4.1. The discussion sections of this guidance corresponding to section 8.4.1 of the HPR, as well as the discussion section relating to the classification of substances in general (Part 2 of the guidance), are relevant to the classification of mixtures if there is data available for the mixture as a whole. The data available on the mixture as a whole must be compared to the classification criteria within each category. If the data available meets the criteria in section 8.4.1, then the mixture must be classified in the category for which the criteria are met.

Care should be exercised in evaluating data on mixtures such that the dose used does not render the results inconclusive. In the case of skin sensitization, current test methods are based on application of a maximised dose, which can only be obtained using a substance by itself and not diluted in a mixture.

Discussion of section 8.4.4 of the Hazardous Products Regulations

Section 8.4.4 of the HPR describes the second step in the tiered approach for the classification of mixtures for respiratory or skin sensitization.

When there is no data or insufficient data on the mixture as a whole, bridging principles must be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

If, based on bridging principles, the mixture can be classified as a respiratory sensitizer and/or skin sensitizer, the mixture must be classified accordingly. If the mixture does not meet the criteria to be classified as a respiratory sensitizer or skin sensitizer based on bridging principles or there are insufficient data to apply bridging principles, then it is necessary to proceed to the next step in the classification process.

Discussion of section 8.4.5 of the Hazardous Products Regulations

Respiratory Sensitization

For classification of mixtures using ingredient data for respiratory sensitization, a mixture is classified in Respiratory Sensitizer — Category 1 or 1A, if it contains at least 1 ingredient at ≥ 0.1% which is classified in Respiratory Sensitizer — Category 1 or 1A, respectively.

For respiratory sensitization classification based on Category 1B ingredients, the physical state and concentration of the ingredient needs to be considered, as follows:

• If the ingredient is a solid or liquid classified in Respiratory Sensitizer — Category 1B, and is present in the mixture at ≥ 1.0%, then the mixture is classified in Respiratory Sensitizer — Category 1B.
• If the ingredient is a gas classified in Respiratory Sensitizer — Category 1B, and is present in the mixture at ≥ 0.2%, then the mixture is classified in Respiratory Sensitizer — Category 1B.

Skin Sensitization

For classification of mixtures using ingredient data for skin sensitization, a mixture is classified in Skin Sensitizer — Category 1 or 1A, if it contains at least 1 ingredient at ≥ 0.1% which is classified in Skin Sensitizer — Category 1 or 1A, respectively.

For skin sensitization classification based on Category 1B ingredients, a mixture is classified in Skin Sensitizer — Category 1B if it does not contain at ≥ 0.1% any ingredients classified in Skin Sensitizer — Category 1A and it contains at least 1 ingredient at ≥ 1.0% which is classified in Skin Sensitizer — Category 1B.

There are exceptions to the concentration limits established in section 8.4.5 of the HPR for classifying mixtures. Although concentration limits have been established in section 8.4.5, when an ingredient presents the hazard at a concentration which is below the concentration limit, and the mixture contains the ingredient at or above that concentration, the mixture must be classified in the category for which it meets the criteria. Refer to section 2.5 of the HPR and its discussion in Part 2 of this guidance for details.

Hazard Communication

The symbols, signal words, hazard statements and precautionary statements for Respiratory or Skin Sensitization — Category 1 are specified in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017, pp. 353-354.

It should be noted that there is no differentiation in hazard communication between the 2 sub-categories of Category 1; Category 1A and 1B.

When a substance or mixture meets criteria as both a respiratory and a skin sensitizer, the hazard communication requirements for each class and category apply.

Classification of Respiratory or Skin Sensitization for Substances Examples

Example 8.4.1: (ECHA Guidance, 2017, p. 359)

Available data

In a cohort of 51 workers exposed to substance X, 26 (51%) were diagnosed with occupational asthma and 12 of the 26 also experienced occupational rhinitis. The diagnosis was based on specific bronchial challenge tests with substance X.

Classification

Respiratory Sensitizer — Category 1

Rationale

There is sufficient human evidence to conclude that substance X caused the respiratory hypersensitivity, that is, asthma and rhinitis. Sub-categorization was not considered as there is currently no clear way to establish subcategories.

Example 8.4.2: (ECHA Guidance, 2017, p. 357)

Available data

Substance Y gave a positive result in the Local Lymph Node Assay with an EC3 value of 10.4%.

Classification

Skin Sensitizer — Category 1B

Rationale

The EC3 value is above the 2% cut-off for a classification in Category 1A. Therefore, Category 1A is ruled out. An EC3 > 2% does, however, fall within the criteria for Category 1B.

Classification of Respiratory or Skin Sensitization for Mixtures Examples

Example 8.4.3:

Available data

Data for the mixture as a whole is not available and bridging principles cannot be applied, thus classification is based on the classified ingredients.

A mixture contains substance T at 0.01%. Substance T is a very strong respiratory sensitizer as there is data available demonstrating that it causes respiratory hypersensitivity at concentrations as low as 0.001%. Substance T is a Respiratory Sensitizer — Category 1A.

There are no other ingredients in the mixture that meet the criteria for a respiratory sensitization classification.

Classification

Respiratory Sensitizer — Category 1

Rationale

As per subsection 2.5(1) of the HPR, if an ingredient is present in a mixture at a lower concentration than the concentration limit for a particular category, but still presents the hazard identified by the category, the mixture must be classified in that category or subcategory. Therefore, even though substance T is in the product below 0.1%, since there is evidence that substance T causes respiratory sensitization at concentrations which are equal to or less than the concentration of the ingredient in the mixture, the mixture must also be classified in Respiratory Sensitizer — Category 1.

Example 8.4.4:

Available data

Data for the mixture as a whole is not available and bridging principles cannot be applied, thus classification is based on the classified ingredients.

Ingredient X is in the product at 0.8% and meets the criteria to be classified in Skin Sensitizer — Category 1B. There is no data indicating that it causes sensitization at this, or lower concentrations. The other ingredients in the mixture do not meet the criteria to be classified in Skin Sensitizers.

Classification

No Classification

Rationale

The cut-off value for Category 1B in a mixture for skin sensitization is 1.0%. Since the concentration of ingredient X falls below this cut-off, the mixture is not classified.

Subpart 5 Germ Cell Mutagenicity

Discussion – Mutagenicity and Mutation

Mutagenicity is the ability of some substances and mixtures to modify the genetic material of cells or organisms in ways that allow the changes to be transmitted during cell division. These changes are permanent and are referred to as mutations. The substance or mixture causing the change is referred to as a mutagen. Mutations can occur in the germ cells (sperm or ova) or in somatic cells (cells other than the germ cells). Germ cell mutations can be passed on to the organism's offspring. For this endpoint, there is no effect (other than the mutation) on the exposed organism; rather, the effect is passed on to future generations. Somatic cell mutations are not transmitted to the next generation. They can cause altered cell growth or cell death in the exposed organism.

There are several types of mutations:

• Gene mutation – a change in DNA sequence within a gene
• Chromosome aberration – a change in the chromosome structure
• Aneuploidy / polyploidy – an increase or decrease, respectively, in the number of chromosomes.

(OSHA Hazard Classification Guidance 2016, p. 135) (ECHA Guidance, 2017, pp. 362, 366)

Discussion – Genotoxicity

Genotoxicity is a more general term applied to substances, mixtures or processes which alter the structure, information content, or segregation of DNA. Genotoxicity test results are usually taken as indicators for mutagenic effects (GHS, seventh revised edition, 2017, paragraph 3.5.1.5).

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of section 8.5.1 of the Hazardous Products Regulations

This hazard class is primarily concerned with chemicals that may cause mutations in the germ cells of humans that can be transmitted to progeny (offspring). To arrive at a classification, test results are considered from experiments determining mutagenic and/or genotoxic effects in germ and/or somatic cells of exposed animals. Mutagenic and/or genotoxic effects determined in in vitro tests may also be considered. (GHS, seventh revised edition, 2017, paragraph 3.5.2.2).

Classification is hazard-based, meaning that substances are classified on the basis of their intrinsic ability to induce mutations in germ cells (GHS, seventh revised edition, 2017, paragraph 3.5.2.3). Care should be taken when applying the classification criteria specified in section 8.5.1 of the HPR with respect to the use of mutagenicity test results versus genotoxicity test results. In general, results from mutagenicity tests are more conclusive and representative for Germ Cell Mutagenicity than results from a genotoxicity test (GHS, seventh revised edition, 2017, paragraph 3.5.1.5). Examples of the different types of tests are given in the discussion of Category 1 and Category 2, below.

Classification of a substance or mixture in this hazard class offers supporting information with respect to the classification of substances and mixtures for carcinogenicity (see Subpart 6 of Part 8 of the HPR- Carcinogenicity). It is increasingly accepted that the process of chemical-induced tumorigenesis in humans and animals involves genetic changes in proto-oncogenes and/or tumour suppresser genes of somatic cells. Therefore, the demonstration of mutagenic properties in somatic and/or germ cells of mammals in vivo may have implications for the potential classification of substances and mixtures for carcinogenicity (GHS, seventh revised edition, 2017, section 3.5.5.2).

There are 2 categories for Germ Cell Mutagenicity classification, Category 1 and Category 2. Category 1 may be further subdivided into Category 1A and 1B. Category 1 germ cell mutagens are substances known to induce heritable mutations in the germ cells of humans (Category 1A) or that should be regarded as if they induce heritable mutations in the germ cells of humans (Category 1B). Category 2 germ cell mutagens are substances of concern due to the possibility that they may induce heritable mutations in the germ cells of humans. (GHS, seventh revised edition, 2017, Figure 3.5.1)

Category 1

Category 1 germ cell mutagens are subdivided into Category 1A, if the basis for classification is human epidemiological data, and Category 1B, if the basis for classification is other mammalian data, as outlined in item 2 of section 8.5.1 of the HPR. Substances classified for Germ Cell Mutagenicity must be classified in either Category 1A or Category 1B specifically, rather than the more generic Category 1 classification. Since the available data is either of 1 type (human epidemiological data) or the other (other mammalian data), the subdivision is always possible.

Health Canada is not aware, at the time of writing, of any examples of substances that are Category 1A mutagens, as epidemiological studies have yet to provide sufficient evidence. Hereditary diseases in humans typically have an unknown origin and show varying distributions in different populations. Due to the random distribution of mutations in the genome it is not expected that 1 particular substance would necessarily induce 1 particular genetic disorder (ECHA Guidance, 2017, p. 365).

There are 3 possible criteria that fulfill a Category 1B classification:

• Positive results from in vivo germ cell mutagenicity tests in mammals. Examples of in vivo heritable germ cell mutagenicity tests include:
  • OECD TG 478 – Rodent dominant lethal mutation test: Dominant lethal effects cause embryonic or fetal death indicating the substance has affected the germinal tissue. Dominant lethal effects are generally accepted to be the result of chromosomal aberrations. A positive result is indicated by a statistically significant, dose-related increase in the number of dominant lethals.
  • OECD TG 485 – Mouse heritable translocation assay: This test detects structural and numerical chromosome changes in mammalian germ cells recovered in first generation progeny. A positive result is indicated by a statistically significant increase in the number of translocations observed for at least 1 test point. A positive result may also be based on the detection of a statistically significant, dose-related increase in the number of translocations observed.

(GHS, seventh revised edition, 2017, paragraph 3.5.2.5)

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects)

• Positive results from in vivo somatic cell mutagenicity tests and evidence for the potential to cause germ cell mutations. Examples of in vivo somatic cell mutagenicity tests include:
  • OECD TG 475 – Mammalian bone marrow chromosome aberration test: This test detects structural chromosome aberrations induced by test substances in bone marrow cells of animals, typically rodents. A positive result can be indicated by a dose-related increase in the relative number of cells with chromosome aberrations, or a clear increase in the number of cells with aberrations in a single dose group at a single sampling time.
  • OECD TG 484 – Mouse spot test: This test detects a mutation in, or a loss of, the dominant allele of a target gene which controls the pigmentation of the coat hairs in a melanoblast. The mutation results in the expression of the recessive phenotype in its descendant cells, and the observation of a spot of changed colour in the coat of the resulting mouse. A positive result can be indicated by a statistically significant, dose-related increase in the frequency of genetically relevant spots.
  • OECD TG 474 – Mammalian erythrocyte micronucleus test: This test detects damage induced by the test substance to the chromosomes or the mitotic apparatus of erythroblasts. Damage is detected by analysis of erythrocytes as sampled in bone marrow and/or peripheral blood cells of animals, typically rodents. A positive result can be indicated by a dose-related increase in the number of micronucleated cells, or a clear increase in the number of micronucleated cells in a single dose group at a single sampling time.

(GHS, seventh revised edition, 2017, paragraph 3.5.2.6)

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects)

Evidence of the potential to cause germ cell mutations can come from test results such as:

• positive in vivo mutagenicity or positive in vivo genotoxicity test results in germ cells; or
• evidence of interaction with the genetic material of germ cells.

Examples of in vivo mutagenicity tests in germ cells are:

• OECD TG 483 – Mammalian spermatogonial chromosome aberration test: This test measures chromosome events in mammalian spermatogonial germ cells and therefore is expected to be predictive of induction of inheritable mutations in germ cells. A positive result can be indicated by a dose-related increase in the relative number of cells with chromosome aberrations, or a clear increase in the number of cells with aberrations in a single dose group at a single sampling time.
• Spermatid micronucleus assay

Examples of in vivo genotoxicity tests in germ cells are:

• Sister chromatid exchange (SCE) analysis in spermatogonia
• Unscheduled DNA synthesis test (UDS) in testicular cells

(GHS, seventh revised edition, 2017, paragraph 3.5.2.7)

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects)

• Data on human germ cells demonstrating mutagenic effects. The mutagenic effects are applicable with or without evidence of transmission to offspring, and may include increased frequency of aneuploidy in sperm of exposed men.

Category 2

Category 2 germ cell mutagens do not fall into further subcategorization. There are 3 possible criteria that fulfill a Category 2 classification:

• Positive results from in vivo somatic cell mutagenicity tests in mammals.

Examples of in vivo somatic cell mutagenicity tests are given above in criteria (b) for Category 1B classification. If the additional evidence for the potential to cause mutations in germ cells is not available or not sufficient to meet Category 1B classification, the substance falls into Category 2; that is, the positive in vivo somatic cell results on their own are sufficient for classification in Category 2.

• Positive results from in vivo somatic cell genotoxicity tests and positive results from in vitro mutagenicity tests. Examples of in vivo somatic cell genotoxicity tests include:
  • OECD TG 486 – Liver unscheduled DNA synthesis (UDS) in vivo: A test to identify substances that induce DNA repair in liver cells of treated animals. Criteria for positive responses include net nuclear grain (NNG) value(s) above a pre-set threshold, which is justified on the basis of laboratory historical data, and NNG value(s) significantly greater than the concurrent control.
  • Mammalian bone marrow Sister Chromatid Exchanges (SCE)

(GHS, seventh revised edition, 2017, paragraph 3.5.2.8)

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects)

Examples of in vitro mutagenicity tests include:

• OECD TG 473 – In vitro mammalian chromosome aberration test: This test is used to identify agents that cause structural chromosome aberrations in cultured mammalian cells (for example, Chinese hamster fibroblasts, human or other mammalian peripheral blood lymphocytes). A positive result is indicated by a concentration-related increase or a reproducible increase in the number of cells with chromosome aberrations.
• OECD TG 476 – In vitro mammalian cell gene mutation test: This test detects gene mutations. Suitable cell lines include L5178Y mouse lymphoma cells, the CHO, AS52 and V79 lines of Chinese hamster cells, and TK6 human lymphoblastoid cells. In these cell lines, the most commonly-used genetic endpoints measure mutation at thymidine kinase (TK) and hypoxanthine-guanine phosphoribosyl transferase (HPRT), and a transgene of xanthine-guanine phosphoribosyl transferase (XPRT). A positive result is indicated by a concentration-related or a reproducible increase in mutant frequency.
• OECD TG 471 – Bacterial reverse mutation tests: This test uses amino-acid requiring strains of Salmonella typhimurium and Escherichia coli to detect point mutations, which involve substitution, addition, or deletion of 1 or a few DNA base pairs. The test detects mutations which revert mutations present in the test strains, and restore the functional capability of the bacteria to synthesize an essential amino acid. The revertant bacteria are detected by their ability to grow in the absence of the amino acid required by the parent test strain. A positive result is indicated by a concentration-related increase over the range tested and/or a reproducible increase at 1 or more concentrations in the number of revertant colonies per plate in at least 1 strain with or without metabolic activation system.

(GHS, seventh revised edition, 2017, paragraph 3.5.2.9)

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects)

• Positive results from in vitro mutagenicity tests in mammalian cells and a structure-activity relationship with a Category 1A germ cell mutagen. Note that only in vitro mutagenicity tests in mammalian cells are acceptable when applying this criteria. Therefore, OECD TG 471, which tests bacteria, is not applicable. The other in vitro test examples given above are applicable.

Since there are, to the best of Health Canada's knowledge at present, no defined Category 1A germ cell mutagens, this criterion cannot, at this time, be applied.

Note: As new, scientifically valid tests are developed, they may also be considered for the classification of substances and mixtures in this hazard class.

Evaluating Mutagenicity/Genotoxicity Test Results

When evaluating results from mutagenicity and genotoxicity tests, there are many factors to take into consideration, depending on whether the results are positive, negative or contradictory. Some considerations are outlined below:

Considerations when evaluating positive test results

• In those instances where a single well-conducted test using a scientifically valid test method is used for classification, it must provide clear and unambiguously positive results (GHS, seventh revised edition, 2017, paragraph 3.5.2.10).
• Positive results in the in vitro Sister Chromatid Exchange (SCE) assay should be viewed with caution, as this assay is associated with a relatively high incidence of false positive results. For example, a positive result in this assay would not be considered to be evidence of a significant clastogenic potential if negative results were available in an in vitro chromosome aberration assay (OSHA Hazard Classification Guidance 2016, p. 142).
• Interpretation of positive results from DNA binding assays should be viewed with caution as these assays are only considered to be indicators of DNA damage. Consequently, the observance of in vivo DNA adducts alone in the absence of positive findings from in vitro assays is generally not considered sufficient evidence of a significant genotoxic potential in vivo (OSHA Hazard Classification Guidance 2016, p. 142).
• The consequences of "positive" findings only at highly toxic/cytotoxic concentrations, and the presence or absence of a dose-response relationship, should be considered. The default assumption for genotoxic chemicals, in the absence of mechanistic evidence to the contrary, is that they have a linear dose response relationship. However, both direct and indirect mechanisms of genotoxicity can be non-linear or threshold, and sometimes this default assumption may be inappropriate. When interpreting positive results, considerations of the dose-response relationship and of possible mechanisms of action are important components of a hazard assessment (OSHA Hazard Classification Guidance 2016, p. 142).

Considerations when evaluating contradictory test results

• Conflicting results obtained between non-mammalian systems and mammalian cell tests may be addressed by considering possible differences in substance uptake, metabolism or in the organization of genetic material. The results of mammalian tests may be considered of higher significance (OSHA Hazard Classification Guidance 2016, p. 142).
• If contradictory findings are obtained in vitro and in vivo, in general, the results of in vivo tests have a higher degree of reliability. However, for evaluation of negative results in vivo, it should be considered whether there is adequate evidence of target tissue exposure (OSHA Hazard Classification Guidance 2016, p. 142).
• The sensitivity and specificity of different test systems varies for different classes of substances. If available test data for other related substances permits assessment of the relative performance of different assays, as applied to the substance under evaluation, the result from the test system known to produce more accurate responses should be given greater weight (OSHA Hazard Classification Guidance 2016, p. 142).
• Conflicting results may also be available from the same test, performed by different laboratories or on different occasions. In this case, an overall evaluation of the data will be required. In particular, the quality of each of the studies and of the data provided should be evaluated, with special consideration given to the study design, reproducibility of data, dose-effect relationships, and biological relevance of the findings. The purity of the test substance may also be a factor to take into account. In the case where an OECD guideline is available for a test method, a study that adheres to the requirements stated in the guideline is regarded as being of higher quality. Furthermore, studies compliant with Good Laboratory Practices may be regarded as being of a higher quality (OSHA Hazard Classification Guidance 2016, p. 143).

Considerations when evaluating negative test results

• Were the doses or concentrations of test substance used high enough?
• Was the test system used sensitive to the nature of the genotoxic changes that might have been expected?
• Were appropriate concentrations maintained in tests conducted in vitro? For example, was the volatility of the test substance taken into consideration?
• For in vitro test systems, was the metabolic activation suitable?
• For in vivo studies, was the test substance reaching the target organ? For example, was toxicokinetic data taken into consideration?
• Was the test substance reactive? For example, were the rate of hydrolysis, electrophilicity, presence or absence of structural alerts and other available indications taken into consideration?
• What was the response of the positive and negative controls?

(OSHA Hazard Classification Guidance 2016, p. 141)

Classification of Mixtures

Discussion of section 8.5.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for germ cell mutagenicity, meaning that the procedures described in sections 8.5.3 to 8.5.5 must be followed in the order in which these sections appear in the HPR.

As specified in sections 8.5.3 and 8.5.4, the classification of mixtures is based on evaluation of the available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified as germ cell mutagens. However, if there are test data for the mixture as a whole, these data may be used to classify the mixture, instead of data on the individual ingredients. Finally, section 8.5.5 specifies which bridging principles may be applied to the Germ Cell Mutagenicity hazard class.

Discussion of section 8.5.3 of the Hazardous Products Regulations

Subject to paragraphs 8.5.3(1)(a) and (b), subsection 8.5.3(1) of the HPR specifies that, if a mixture contains at least 1 ingredient that is classified in Germ Cell Mutagenicity — Category 1A and the ingredient is present at a concentration of ≥ 0.1%, then the mixture must be classified in Germ Cell Mutagenicity — Category 1 or Germ Cell Mutagenicity — Category 1A. Subject to paragraphs 8.5.3(2)(a) and (b), subsection 8.5.3(2) of the HPR specifies that, if a mixture contains at least 1 ingredient that is classified in Germ Cell Mutagenicity — Category 1B and the ingredient is present at a concentration of ≥ 0.1%, and the mixture does not contain a Category 1A ingredient at a concentration of ≥ 0.1%, then the mixture must be classified in Germ Cell Mutagenicity — Category 1 or Germ Cell Mutagenicity — Category 1B. Note that, as specified in paragraph 3(5)(m) of the HPR, the symbol, signal word, hazard statement and precautionary statements are the same for Germ Cell Mutagenicity — Category 1, 1A and 1B.

The additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Germ Cell Mutagenicity — Category 1A or 1B are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 0.1% concentration cut-off.

If there are test data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that, as the concentration of a germ cell mutagen is reduced in a mixture, the dilution effect may result in a misleading test result (that is, a false negative) if the study was not appropriately designed to factor in the concentration of the germ cell mutagen in the mixture (OSHA Hazard Classification Guidance 2016, p. 138).

Therefore, the test results for the mixture as a whole must be shown to be conclusive, taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation and analysis of germ cell mutagenicity test systems (GHS, seventh revised edition, 2017, section 3.5.3.1). If the results for the mixture as a whole are relevant and conclusive and meet the criteria for Germ Cell Mutagenicity in accordance with section 8.5.1 of the HPR, the results must be applied to classify the mixture as a germ cell mutagen.

If the results for the mixture as a whole demonstrate that the mixture is not a germ cell mutagen, based on an in vivo heritable germ cell mutagenicity test that was performed according to generally accepted standards of good scientific practice, and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified as a germ cell mutagen, even when Category 1A or 1B germ cell mutagen ingredients are present at or above the established cut-off concentration of 0.1%.

Discussion of section 8.5.4 of the Hazardous Products Regulations

If at least 1 ingredient present in the mixture at a concentration of ≥ 1.0% is classified as Germ Cell Mutagenicity — Category 2, then the mixture is classified as Germ Cell Mutagenicity — Category 2. Note that the additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Germ Cell Mutagenicity — Category 2 are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 1.0% concentration cut-off.

If there are test data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that, as the concentration of a germ cell mutagen is reduced in a mixture, the dilution effect may result in a misleading test result (that is, a false negative) if the study was not appropriately designed to factor in the concentration of the germ cell mutagen in the mixture (OSHA Hazard Classification Guidance 2016, p. 138).

Therefore, the test results for the mixture as a whole must be shown to be conclusive, taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation and analysis of germ cell mutagenicity test systems (GHS, seventh revised edition, 2017, section 3.5.3.1). If the results for the mixture as a whole are relevant and conclusive, and meet the criteria for Germ Cell Mutagenicity in accordance with section 8.5.1 of the HPR, the results must be applied to classify the mixture as a germ cell mutagen.

If the results for the mixture as a whole demonstrate that the mixture is not a germ cell mutagen, based on an in vivo heritable germ cell mutagenicity test that was performed according to generally accepted standards of good scientific practice, and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified as a germ cell mutagen, even when Category 2 germ cell mutagen ingredients are present at or above the established cut-off concentration of 1.0%.

Discussion of section 8.5.5 of the Hazardous Products Regulations

For this hazard class, the use of bridging principles is the final step in the tiered approach for the classification of mixtures. When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there is sufficient data available on similar tested mixtures and on the individual hazardous ingredients within the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

Note that not all of the bridging principles apply to this hazard class. Only dilution, production batches, and substantially similar mixtures are applicable. Increase in concentration of hazardous ingredient, interpolation and aerosols are not used for this hazard class.

If data on another mixture are used in the application of the bridging principles, the data on that mixture must be conclusive for the mixture as a whole, as discussed above under sections 8.5.3 and 8.5.4 of the HPR (OSHA Hazard Classification Guidance 2016, p. 138).

Hazard Communication

The symbol, signal words, hazard statements, and precautionary statements for Germ Cell Mutagenicity Category 1 and Category 2 are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, p. 355. Paragraph 3(5)(m) of the HPR specifies that if a hazardous product is classified in the subcategory Germ Cell Mutagenicity — Category 1A or in the subcategory Germ Cell Mutagenicity — Category 1B, the information elements specified for the category Germ Cell Mutagenicity — Category 1 apply.

Note that the symbol and precautionary statements are the same for Category 1 and Category 2; the signal word and hazard statement are different between the 2 categories.

As part of the hazard statement, the route of exposure must be specified if it has been conclusively proven that no other routes of exposure cause the effect. In order to be able to specify the route of exposure, test data need to be available for all 3 relevant routes (oral, dermal and inhalation), and the data must clearly indicate that only 1 route leads to positive results. It is estimated that such circumstances rarely, if ever, exist (ECHA Guidance, 2017, p. 374).

Classification of Germ Cell Mutagenicity for Substances Examples

Example 8.5.1:

Available data

Substance X has shown positive results in the Rodent Dominant Lethal Mutation test (OECD TG 478).

Classification

Germ Cell Mutagenicity — Category 1B

Rationale

The test result fulfills Item 2 (a) of section 8.5.1 of the HPR – a positive result from an in vivo heritable germ cell mutagenicity test in mammals.

Example 8.5.2:

Available data

Substance Y has shown positive results in the Mammalian Bone Marrow Chromosome Aberration test (OECD TG 475).

Classification

Germ Cell Mutagenicity — Category 2

Rationale

The test result fulfills Item 3 (a) of section 8.5.1 of the HPR – a positive result from an in vivo somatic cell mutagenicity test in mammals.

(OSHA Hazard Classification Guidance 2016, p. 146)

Classification of Germ Cell Mutagenicity for Mixtures Example

Example 8.5.3:

(OSHA Hazard Classification Guidance 2016, p. 147)

Available data

Table 8.23 Classification of Germ Cell Mutagenicity for mixtures based on the concentration of the components.

Component	Concentration (w/w)%	Classification
A	0.09	Germ Cell Mutagenicity — Category 1B
B	94.91	Not classified
C	3	Germ Cell Mutagenicity — Category 2
D	2	Germ Cell Mutagenicity — Category 1B

Data for the mixture as a whole is not available.

Classification

Germ Cell Mutagenicity — Category 1or Category 1B

Rationale

Component B is not classified as a germ cell mutagen; therefore, it is not considered when classifying the mixture.

Component A falls below the 0.1% cut-off value for Category 1 and has not been shown to cause mutagenic effects below this concentration. Therefore, it is not considered when classifying.

Component C is present at a concentration that is greater than 1.0%. Therefore, the mixture meets the criteria to be classified in Category 2.

Component D is present at a concentration that is greater than 0.1%. There are no Category 1A ingredients. Therefore, the mixture meets the criteria to be classified as Category 1 or Category 1B.

As specified in subsection 2(2) of the HPR, where a product, mixture, material or substance meets the criteria to be classified in a category or subcategory of a hazard class that represents a more severe hazard in a classification table, it is not necessary to evaluate the product, mixture, material or substance with regard to a category or subcategory in the same classification table that represents a less severe hazard. The most severe category is used to classify the mixture.

Subpart 6 Carcinogenicity

Discussion

In the GHS background guidance to the Carcinogenicity hazard class, the GHS refers to the terms "sufficient evidence of carcinogenicity" and "limited evidence of carcinogenicity" as defined by the International Agency for Research on Cancer (IARC) in the context of carcinogenicity in humans and in experimental animals. Knowledge of these terms may assist suppliers in interpreting the criteria set out in the Table to section 8.6.1 of the HPR.

Carcinogenicity in humans according to IARC

The evidence relevant to carcinogenicity from studies in humans is classified into 1 of the following categories:

1. Sufficient evidence of carcinogenicity: a causal relationship has been established between exposure to the agent and human cancer. That is, a positive relationship has been observed between the exposure and cancer in studies in which chance, bias and confounding could be ruled out with reasonable confidence;
2. Limited evidence of carcinogenicity: A positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence.

Carcinogenicity in experimental animals according to IARC

The evidence relevant to carcinogenicity in experimental animals is classified into 1 of the following categories:

a) Sufficient evidence of carcinogenicity: a causal relationship has been established between the agent and an increased incidence of malignant neoplasms or of an appropriate combination of benign and malignant neoplasms in (i) 2 or more species of animals or (ii) in 2 or more independent studies in 1 species carried out at different times or in different laboratories or under different protocols;

Exceptionally, a single study in 1 species might be considered to provide sufficient evidence of carcinogenicity when malignant neoplasms occur to an unusual degree with regard to incidence, site, type of tumour or age at onset;

b) Limited evidence of carcinogenicity: The data suggest a carcinogenic effect but are limited for making a definitive evaluation because, for example, (i) the evidence of carcinogenicity is restricted to a single experiment and does not meet the criteria for sufficient evidence; or (ii) there are unresolved questions about the adequacy of the design, conduct, or interpretation of the available studies; or (iii) the agent increases the incidence only of benign neoplasms or lesions of uncertain neoplastic potential, or of certain neoplasms which may occur spontaneously in high incidences in certain strains; or (iv) the agent increases tumour multiplicity or decreases tumour latency but does not increase tumour incidence; or (v) the evidence of carcinogenicity is restricted to initiation–promotion studies; or (vi) the evidence of carcinogenicity is restricted to observational studies in non-laboratory animals (for example, companion animals).

(IARC Preamble; GHS sections 3.6.5.3.1.1 and 3.6.5.3.1.2)

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of section 8.6.1 of the Hazardous Products Regulations

Definitions

Substances and mixtures are deemed carcinogenic according to their potential to cause cancer in humans. However, in most cases, epidemiological studies in humans are not available or sufficient, and classification is based primarily on animal studies. Substances and mixtures which have induced benign and malignant tumours in well performed experimental studies on animals are considered also to be presumed or suspected human carcinogens unless there is strong evidence that the mechanism of tumour formation is not relevant for humans (GHS, seventh revised edition, 2017, section 3.6.1).

There are 2 categories for Carcinogenicity classification according to section 8.6.1 of the HPR: Category 1 and Category 2. Category 1 may be further subdivided into Category 1A and 1B; however, sub-categorization may not always be possible. If sub-categorization is not possible, a less specific Category 1 classification is applied. Category 1A carcinogens are substances and mixtures that are known to be carcinogens for humans (based on human data). Category 1B carcinogens are substances and mixtures that are presumed to be carcinogens for humans (largely based on animal data). Category 2 carcinogens are substances and mixtures that are suspected to be carcinogens for humans (GHS, seventh revised edition, 2017, Figure 3.6.1).

Conclusions drawn from human and animal studies differ in the following way:

• human data demonstrate a causal relationship or a positive association between human exposure and the development of cancer, whereas
• animal data demonstrate a causal relationship or a positive association between exposure to the substance or mixture and an increased incidence of tumours.

Classification of a substance or mixture for carcinogenicity involves the enumeration of tumours in human and animal studies and determination of their level of statistical significance (GHS, seventh revised edition, 2017, paragraph 3.6.2.4), along with consideration of all other relevant information as appropriate. A number of other factors need to be considered which influence the overall likelihood that a substance or mixture poses a carcinogenic hazard in humans. Relevant information helps increase or decrease the level of concern for human carcinogenicity. The emphasis on each piece of information depends on the amount and strength of evidence it provides. In general, there is a requirement for more complete information to decrease than to increase the level of concern (GHS, seventh revised edition, 2017, paragraph 3.6.2.5.1). Information that may be considered when assessing the overall level of concern, based on animal test results, includes:

1. Tumour type and background incidence: By default, carcinogenic effects in experimental animals are considered relevant to humans and are considered for classification. Only when there is data showing that a certain type of tumour is not relevant to humans should this tumour type be excluded for classification. There are several reasons why a tumour observed in animals could be considered not relevant for humans or could be considered of less concern for humans:
   • In most of these cases, the tumour occurs via a mode of action which does not occur in humans.
   • In some cases, the tumour could occur in a tissue known to be overly susceptible to development of certain tumours in the species tested. Consequently, this observation could be considered to be less relevant for humans.
   • A tumour could occur in a tissue with no equivalent in humans.
   • A carcinogen that increases the incidence of a neoplastic disease that is rare in the test species or strain is of greater concern than a carcinogen that increases the incidence of a neoplasm having a high spontaneous incidence.
2. Multisite responses: Substances and mixtures which cause tumours at multiple sites tend to be more potent carcinogens than those causing tumours at only 1 site in 1 species. This tendency is often true for substances and mixtures which are mutagenic. Thus, if a substance or mixture causes tumours at multiple sites, then it is considered to be carcinogenic. The tumour profile should be taken into account when considering the most appropriate classification.
3. Progression of lesions to malignancy: If the substance or mixture has been shown to cause malignant tumours, then this is generally sufficient evidence for classification in Category 1B. Generally speaking, the induction of only benign tumours is of lesser concern for carcinogenicity than the induction of malignant tumours. However, benign tumours could also be of significant concern if they are a type of tumour that has the potential to progress to malignancy. Therefore, any indication that the observed tumours have the potential to progress to malignancy will increase the level of concern. Also, for example, brain tumours are of concern in and of themselves. Benign tumours are potentially serious depending on their size, growth rate, and site of origin.
4. Reduced tumour latency: The latency of tumour development (that is, how quickly a substance or mixture induces tumours) reflects the potency of a carcinogen. This observation is particularly true for mutagenic substances and mixtures, which often induce tumours more rapidly than non-genotoxic agents. Substances and mixtures producing tumours with reduced latency could be considered as carcinogenic, even if the tumour incidence is not statistically significant.
5. Whether responses are in 1 or both sexes: Any case of gender-specific tumours must be evaluated in light of the total tumourigenic response to the substance or mixture observed at other sites (multi-site responses or incidence above background) in determining the carcinogenic potential of the substance or mixture. If tumours are seen only in 1 sex of an animal species, the mode of action must be carefully evaluated to see if the response is consistent with the postulated mode of action. Effects seen only in 1 sex in a test species may be less convincing than effects seen in both sexes, unless there is a clear pathophysiological difference consistent with the mode of action to explain the single sex response.
6. Whether responses are in a single species or several species: Positive responses in several species indicate that the substance or mixture is a carcinogen. Taking into account all of the factors, substances and mixtures with positive outcomes in 2 or more species should be considered to be classified in Category 1B until the human relevance of animal results are assessed in their entirety. The majority of proven human carcinogens have caused cancer in more than 1 species.

   Positive results for 1 species in at least 2 independent studies, or a single positive study showing unusually strong evidence of malignancy should also lead to Category 1B classification. The classification criteria indicate that carcinogenicity in a single animal study should be considered sufficient to classify in Category 1B in the absence of any other data.

   A single study in 1 species and sex should be considered sufficient for classification in Category 1B when malignant neoplasms occur to an unusual degree with regard to incidence, site, type of tumour or age at onset, or when there are strong findings of tumours at multiple sites.

   Also, a single study in 1 species and sex in combination with positive in vivo mutagenicity data would be considered sufficient for classification in Category 1B.

7. Structural similarity (or not) to a substance or mixture for which there is good evidence of carcinogenicity: A substance or mixture that has not been tested for carcinogenicity could, in certain instances, be classified in Category 1 or Category 2 based on tumour data from a structural analogue when this information is considered together with substantial support from other factors such as formation of common significant metabolites, for example, for benzidine congener dyes.
8. Routes of exposure: The classification should also take into consideration whether or not the substance or mixture is absorbed by a given route(s); or whether there are only local tumours at the site of administration for the tested route(s), and adequate testing by other major route(s) show lack of carcinogenicity. Most standard carcinogenicity studies use physiological routes of exposure for humans, namely inhalation, oral or dermal exposure. The findings from such routes are usually considered directly relevant for humans. Studies using these routes will generally take precedence over similar studies using other routes of exposure (for example, intra-muscular, sub-cutaneous, intra-peritoneal and intra-tracheal injections or instillations).
9. Comparison of absorption, distribution, metabolism and excretion between test animals and humans: when classifying, it is important to have data on the physico-chemical, toxicokinetic and toxicodynamic properties of the substance or mixture along with data on chemical analogues, such as the structure activity relationship.
10. The possibility of a confounding effect of excessive toxicity at test doses: Tumours occurring only at excessively high doses associated with severe toxicity generally have doubtful potential for predicting carcinogenicity in humans.
11. Tumours occurring only at sites of contact: Tumours occurring only at the site of contact must be carefully evaluated for human relevance. For example, forestomach tumours, following administration by gavage of an irritating or corrosive, non-mutagenic chemical, may be of questionable relevance. Any occurrence of other tumours at distant sites must also be considered.
12. Mode of action and its relevance for humans: Mode of action may include mutagenicity, cytotoxicity with growth stimulation, mitogenesis, or immunosuppression. Mode of action in and of itself, or consideration of comparative metabolism, should be evaluated on a case-by-case basis. One must look closely at any mode of action in animal experiments taking into consideration comparative toxicokinetics/toxicodynamics between the animal test species and humans to determine the relevance of the results to humans. Only if a mode of action of tumour development is conclusively determined not to be operative in humans could the carcinogenic data for that tumour be discounted.

It is recognized that genetic events are central in the overall process of cancer development. Therefore, data of mutagenic activity in vivo may indicate that a substance or mixture has a potential for carcinogenic effects. In general, if a substance or mixture is mutagenic then it will be considered to be potentially carcinogenic in humans. However, mutagenicity data alone are insufficient information to justify a carcinogenicity classification. In some cases, where only in vitro and in vivo mutagenicity data are available without carcinogenicity data, classification in Carcinogenicity — Category 2 could be considered when all factors have been considered such as type and quality of the mutagenicity data, structure activity relationships, etc.

(ECHA Guidance, 2017, pp. 380-387) (GHS, seventh revised edition, 2017, paragraphs 3.6.5.3.2.1 to 3.6.5.3.2.5)

In extrapolation from animals to humans, it is known that the following instances of carcinogenicity may be denied as evidence of human carcinogenicity because the mechanism of tumour formation is considered not relevant for humans:

• Kidney tumours in male rats associated with substances or mixtures causing α2μ- globulin nephropathy
• Pheochromocytomas in male rats exposed to particulates through inhalation secondary to hypoxemia
• Leydig cell adenomas induced by dopamine antagonists or gonadotropin-releasing hormone (GnRH)
• Urinary bladder tumours due to crystals in the bladder
• Forestomach tumours in rodents following administration by gavage of irritating or corrosive, non-genotoxic substances or mixtures
• Certain thyroid tumours in rodents mediated by UDP glucuronyltransferase (UGT) induction
• Liver tumours in rodents conclusively linked to peroxisome proliferation (ECHA Guidance, 2017, p. 387)

Substances evaluated by IARC, NTP or ACGIH

Health Canada considers the determinations of IARC and National Toxicology Program (NTP) as sufficient evidence in establishing the classification of a carcinogen. If the classifier uses the determinations of IARC or NTP then they do not have to conduct their own evaluation with regards to carcinogenicity based on established scientific principles. However, if the classifier does perform their own hazard evaluation and their determination differs from that of IARC and/or NTP, they would need to substantiate with sufficient evidence based on established scientific principles why their classification result differs from that of IARC and/or NTP. Note, in this scenario, the classifier cannot simply cast doubt on some of the evidence used by IARC and/or NTP, rather the classifier would need sufficient quantity and quality of evidence to justify a lower classification. Health Canada may request access, at any time, to that evidence to validate, as required.

• IARC "Monographs on the Evaluation of Carcinogenic Hazards to Humans"
• NTP "Report on Carcinogens"

Table 8.24 below gives the approximate equivalencies between HPR classification and classifications by IARC and NTP.

Table 8.24 Classification correspondence between the HPR, IARC and NTP

IARC	NTP	HPR
Group 1 (carcinogenic to humans)	Known - sufficient evidence of carcinogenicity from studies in humans	Category 1A
Group 2A (probably carcinogenic to humans)	Reasonably Anticipated - Limited evidence of carcinogenicity from studies in humans	Category 1B
Group 2B (possibly carcinogenic to humans) Sufficient evidence of carcinogenicity in experimental animals	Reasonably Anticipated - Sufficient evidence of carcinogenicity from studies in experimental animals	Category 1B
Group 2B (possibly carcinogenic to humans)	Reasonably Anticipated - Less than sufficient evidence of carcinogenicity in humans or laboratory animals; however the substance belongs to a well-defined, structurally- related class of substances whose members are listed in a previous Report on Carcinogens as either "Known" or "Reasonably Anticipated" to be a human carcinogen, or there is convincing relevant information that the agent acts through mechanisms indicating it would likely cause cancer in humans.	Category 2

Correspondence between the HPR and a carcinogenicity designation by the American Conference of Industrial Hygienists (ACGIH) ("Threshold Limit Values for Chemical Substances and Physical Agents in the Work Environment") is not as straightforward. If a substance is not listed by IARC or NTP, but it is listed by ACGIH as Group A1 (confirmed human carcinogen), A2 (suspected human carcinogen) or A3 (confirmed animal carcinogen with unknown relevance to humans), it should be considered a carcinogen under the HPR. The data upon which the ACGIH designation was based and any new scientific data must be evaluated and assessed against the criteria in section 8.6.1 of the HPR to determine the most suitable category. If the substance has both an IARC or NTP classification for carcinogenicity and an ACGIH classification, the IARC or NTP classification would take precedence over the ACGIH classification.

Substances not evaluated by IARC, NTP or ACGIH

If a substance is not specifically addressed by IARC, NTP or ACGIH, this lack of determination does not relieve the supplier or importer of their obligation to consider other available data indicating that carcinogenic effects may result from exposure to the substance. The criteria described in section 8.6.1 of the HPR must be applied in the context of other available data in this regard.

Classification of Mixtures

Discussion of section 8.6.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for carcinogenicity, meaning that the procedures described in sections 8.6.3 to 8.6.5 must be followed in the order in which these sections appear in the HPR.

As specified in sections 8.6.3 and 8.6.4, classification of mixtures for carcinogenicity is based on the evaluation of available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified as carcinogens. However, if there are test data for the mixture as a whole, these data may be used to classify the mixture, instead of data on the individual ingredients. Finally, section 8.6.5 specifies which bridging principles may be applied to the Carcinogenicity hazard class.

Discussion of section 8.6.3 of the Hazardous Products Regulations

Subject to paragraphs 8.6.3(1)(a) and (b), subsection 8.6.3(1) of the HPR specifies that, if a mixture contains at least 1 ingredient that is classified in Carcinogenicity — Category 1A and the ingredient is present at a concentration of ≥ 0.1%, then the mixture must be classified in Carcinogenicity — Category 1 or Carcinogenicity — Category 1A.

Subject to paragraphs 8.6.3(2)(a) and (b), subsection 8.6.3(2) of the HPR specifies that, if a mixture contains at least 1 ingredient that is classified in Carcinogenicity — Category 1B and the ingredient is present at a concentration of ≥ 0.1%, and the mixture does not contain a Category 1A ingredient at a concentration of ≥ 0.1%, then the mixture must be classified in Carcinogenicity — Category 1 or Carcinogenicity — Category 1B.

Note that, as specified in paragraph 3(5)(n) of the HPR, the symbol, signal word, hazard statement and precautionary statements are the same for Carcinogenicity — Category 1, 1A and 1B.

The additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Carcinogenicity — Category 1A or 1B are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 0.1% concentration cut-off.

If there are data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that as the concentration of a carcinogenic ingredient is reduced in a mixture, the dilution effect may result in a misleading test result (that is, a false negative) if the study was not appropriately designed to factor in the concentration of the carcinogenic ingredient in the mixture (OSHA Hazard Classification Guidance 2016, p. 160).

Therefore, the test results for the mixture as a whole must be shown to be conclusive taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation, and analysis of carcinogenicity test systems (GHS, seventh revised edition, 2017, section 3.6.3.1). If the results for the mixture as a whole are relevant and conclusive, based on established scientific principles, and meet the criteria for Carcinogenicity in accordance with section 8.6.1 of the HPR, the results must be applied to classify the mixture as a carcinogen.

If the results for the mixture as a whole demonstrate that the mixture is not carcinogenic, based on a carcinogenicity study that was performed according to generally accepted standards of good scientific practice and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified as a carcinogen even when Category 1, 1A or 1B carcinogenic ingredients are present at or above the established cut-off concentration of 0.1%.

Discussion of section 8.6.4 of the Hazardous Products Regulations

If at least 1 ingredient present in the mixture at a concentration of ≥ 0.1% is classified as Carcinogenicity — Category 2, then the mixture is classified as Carcinogenicity — Category 2. Note that the additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Carcinogenicity — Category 2 are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 0.1% concentration cut-off.

However, if there are data available for the mixture as a whole, these data may be used, instead of data on the individual ingredients, to classify the mixture. The concern with using test data for the mixture as a whole is that as the concentration of a carcinogenic ingredient is reduced in a mixture, the dilution effect may result in a misleading test result (that is, false negative) if the study was not appropriately designed to factor in the concentration of the carcinogenic ingredient in the mixture (OSHA Hazard Classification Guidance 2016, p. 160).

The test results for the mixture as a whole must be shown to be conclusive taking into account dose and other factors based on established scientific principles, such as duration, observation and analysis of carcinogenicity test systems (GHS, seventh revised edition, 2017, section 3.6.3.1).

If the results for the mixture as a whole are deemed relevant and conclusive and meet the criteria for Carcinogenicity in accordance with section 8.6.1 of the HPR, the results must be applied to classify the mixture as a carcinogen.

If the results for the mixture as a whole demonstrate that the mixture is not carcinogenic based on a carcinogenicity study and a scientifically validated method was used, and the study was performed in accordance with generally accepted standards of good scientific practice, the results must be applied. The mixture cannot be classified as a carcinogen even when Category 2 carcinogenic ingredients are present at or above the established cut-off concentration of 0.1%.

Discussion of section 8.6.5 of the Hazardous Products Regulations

The use of bridging principles is the final step in the tiered approach for the classification of mixtures. When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there is sufficient data available on similar tested mixtures and on the individual hazardous ingredients within the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

Not all of the bridging principles apply to this hazard class. Only dilution, production batches, and substantially similar mixtures are applicable. Increase in concentration of hazardous ingredient, interpolation and aerosols are not used for this hazard class.

If data on another mixture are used in the application of the bridging principles, the data on that mixture must be conclusive for the mixture as a whole, as discussed above under sections 8.6.3 and 8.6.4 of the HPR (OSHA Hazard Classification Guidance 2016, p. 161).

Hazard Communication

The symbol, signal words, hazard statements, and precautionary statements for Carcinogenicity Category 1 and Category 2 are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, p. 356. Paragraph 3(5)(n) of the HPR specifies that if a hazardous product is classified in the subcategory Carcinogenicity — Category 1A or in the subcategory Carcinogenicity — Category 1B, the information elements specified for the category Carcinogenicity — Category 1 apply.

Note that the symbol and precautionary statements are the same for Category 1 and Category 2; the signal word and hazard statement are different between the 2 categories.

As part of the hazard statement, the route of exposure must be specified if it has been conclusively proven that no other routes of exposure cause the effect. In order to be able to specify the route of exposure, test data need to be available for all 3 relevant routes (oral, dermal and inhalation), and the data must clearly indicate that only 1 route leads to positive results.

Hazard Communication – Mixtures

Classification of Carcinogenicity for Substances Example

Example 8.6.1:

(OSHA Hazard Classification Guidance 2016, p. 167)

Available data

Listed by IARC as Group 2A (probably carcinogenic to humans).

Listed by NTP as Reasonably Anticipated to be human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.

Classification

Carcinogenicity Category — 1B

Rationale

The substance has been evaluated and determined to be a carcinogen by IARC and NTP. According to the equivalencies illustrated in Table 8.24, the substance should be classified under the HPR in Carcinogenicity — Category 1B.

Classification of Carcinogenicity for Mixtures Example

Example 8.6.2:

(OSHA Hazard Classification Guidance 2016, p. 168)

Available data

Table 8.25 Classification of Carcinogenicity for mixtures based on the concentration of the components.

Component	Concentration (w/w)%	Classification
A	0.05	Carcinogenicity Category 1B
B	45	Not classified
C	0.5	Carcinogenicity Category 2
D	54.45	Not classified

Data for the mixture as a whole is not available.

Classification

Carcinogenicity — Category 2

Rationale

Components B and D are not classified for carcinogenicity; therefore, they are not considered when classifying the mixture.

Component A falls below the 0.1% cut-off value for Category 1 and has not been shown to cause carcinogenic effects below this concentration. Therefore, it is not considered when classifying the mixture.

Component C is present at a concentration of ≥ 0.1% and is classified in Category 2. Therefore, the mixture is classified as Carcinogenicity — Category 2.

Subpart 7 Reproductive Toxicity

Discussion – Reproductive Toxicity

Reproductive toxicity describes the adverse effects induced by a substance or mixture on any aspect of mammalian reproduction, from sexual function and fertility to development of the embryo, fetus and offspring to lactation.

Effects on or via lactation are included in the definition of reproductive toxicity. However, these effects are assessed separately for classification since it is desirable to be able to classify specifically for this endpoint and include hazard warnings directed at lactating mothers (GHS, seventh revised edition, 2017, section 3.7.1.2).

Effectively, a substance (or mixture) could be classified as follows:

1. Reproductive Toxicity — Category 1
2. Reproductive Toxicity — Category 2
3. Reproductive Toxicity — Effects on or via Lactation
4. both Reproductive Toxicity — Category 1 and Reproductive Toxicity — Effects on or via Lactation or
5. both Reproductive Toxicity — Category 2 and Reproductive Toxicity — Effects on or via Lactation

Classification in a Category or Subcategory of the Class

Classification of Substances

Discussion of subsection 8.7.1(1) of the Hazardous Products Regulations

Reproductive Toxicity is divided into 2 categories; Category 1 and Category 2. Category 1 is further subdivided into Category 1A and 1B. Category 1A represents known human reproductive toxicants. Category 1B represents presumed human reproductive toxicants. Category 2 represents suspected human reproductive toxicants.

Category 1A

Category 1A is based on human data from epidemiological studies, clinical data and case reports. A well conducted epidemiological study should include use of appropriate controls, balanced assessment, and consideration of bias or confounding factors (GHS, seventh revised edition, 2017, paragraph 3.7.2.2.3).

Category 1B

Human data is often limited and/or does not provide conclusive support for classification. Classification in Reproductive Toxicity — Category 1B is based on data in experimental animals. According to criterion (a) of Reproductive Toxicity — Category 1B, the data must provide clear evidence of an adverse effect on sexual function and fertility or on development of the embryo, fetus or offspring, in the absence of other toxic effects, including maternal toxicity. According to criterion (b) of Reproductive Toxicity — Category 1, adverse effects occurring together with other toxic effects, such as maternal toxicity, can also be considered. However, the adverse effects on reproduction must not be a secondary non-specific consequence of the other toxic effects. Guidance on the interpretation of maternal toxicity and other toxic effects is provided below.

Category 2

The criteria for Category 2 address situations when there is evidence from humans or experimental animals of an adverse effect on reproduction, possibly supplemented with other information, but the evidence is not sufficiently convincing for a Category 1A or 1B classification. For instance, deficiencies in the study may make the quality of evidence less convincing and a Category 2 classification could be more appropriate.

As with Category 1B, adverse reproductive effects observed in animals must be in the absence of other toxic effects or, if occurring together with other toxic effects, must not be a secondary non-specific consequence of the other toxic effects. However, unless it can be clearly demonstrated that the adverse effects are secondary to the maternal toxicity, classification in Category 2 must be considered.

Classification is intended to be used for substances or mixtures which have an intrinsic, specific property to produce an adverse effect on reproduction. If such an effect is produced solely as a non-specific secondary consequence of other toxic effects, the substance or mixture should not be classified in Reproductive Toxicity hazard class (GHS, seventh revised edition, 2017, paragraph 3.7.2.2.1). It is important to consider the possible influence of maternal toxicity when assessing reproductive toxicity.

Experimental Data (GHS, seventh revised edition, 2017, section 3.7.2.5)

• A number of internationally accepted test methods are available, these include:
  • Methods for developmental toxicity testing. For example:
    • OECD TG 414 – Prenatal Developmental Toxicity Study: This study is designed to provide general information concerning the effects of prenatal exposure on the pregnant test animal and on the developing organism; this may include assessment of maternal effects as well as death, structural abnormalities, or altered growth in the fetus. The dams are exposed to the substance and effects from preimplantation through the entire period of gestation to the day before caesarean section are examined (Details on test method from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects).
    • International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) Guideline S5A, 1993: Detection of Toxicity to Reproduction for Medicinal Products
  • Methods for peri- and post-natal toxicity testing. For example:
    • ICH S5B, 1995: Addendum to Detection of Toxicity to Reproduction for Medicinal Products: Toxicity to Male Fertility
  • Methods for one or two generation reproduction toxicity testing. For example:
    • OECD TG 415 – One Generation Reproduction Toxicity Study: This study is designed to provide general information concerning the effects of a test substance on male and female reproductive performance, such as gonadal function, oestrous cycle, mating behaviour, conception, parturition, lactation, and weaning. The study may also provide preliminary information about developmental toxic effects of the test substance, such as neonatal morbidity, mortality, behaviour, and teratogenesis, and to serve as a guide for subsequent tests. The test substance is administered to both males and females for a period prior to mating and during the mating period. Thereafter, only the females are dosed throughout pregnancy and nursing. The evaluation will include the relationship between the dose of the test substance and the presence or absence, the incidence and severity, of abnormalities, including fertility, clinical abnormalities, body weight changes, effects on mortality and any other toxic effects. It is noted that the OECD has deleted this TG but existing data can still be used for classification.
    • OECD TG 416 – Two Generation Reproductive Toxicity Study: In addition to studying growth and development of the F1 generation, as described for OECD TG 415, this study is also intended to assess the integrity and performance of the male and female reproductive systems as well as growth and development of the F2 generation.
    • OECD TG 443 - Extended One-Generation Reproductive Toxicity Study: This study is designed to provide an evaluation of reproductive and developmental effects that may occur as a result of pre- and postnatal chemical exposure as well as an evaluation of systemic toxicity in pregnant and lactating females and young and adult offspring. The test substance is administered to both males and females for a period prior to mating, during mating, gestation and weaning of their pups. At weaning, pups are selected and assigned to cohorts of animals for reproductive/developmental toxicity testing (cohort 1), developmental neurotoxicity testing (cohort 2) and developmental immunotoxicity testing (cohort 3). The F1 offspring receive further treatment with the test substance from weaning to adulthood. Clinical observations and pathology examinations are performed on all animals for signs of toxicity, with special emphasis on the integrity and performance of the male and female reproductive systems and the health, growth, development and function of the offspring. Part of cohort 1 (cohort 1B) may be extended to include an F2 generation. In this case, procedures for F1 animals will be similar to those for the P animals.

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects).

• Screening tests: In the absence of a full study, screening tests can be used to justify classification, although it is recognized that the quality of this evidence is less reliable than that obtained through full studies (GHS, seventh revised edition, 2017 paragraph 3.7.2.5.2). For example,
  • OECD TG 421 – Reproduction/Developmental Toxicity Screening Test: This test provides initial information on possible effects on reproduction and/or development. It does not provide complete information on all aspects of reproduction and development, offering only limited means of detecting post-natal manifestations of pre-natal exposure, or effects that may be induced during post-natal exposure. Due to the relatively small numbers of animals in the dose groups, the selectivity of the endpoints, and the short duration of the study, this method will not provide evidence for definite claims of no effects. Dosing is similar to that described above for OECD TG 415; however, the pre-mating and post-delivery periods are shortened.
  • OECD TG 422 – Combined Repeated Dose Toxicity Study with Reproduction/Developmental Toxicity Screening Test: This test provides information on the possible health hazards likely to arise from repeated exposure over a relatively limited period of time (at least 28 days), combined with the reproduction/developmental toxicity screening test as described above for OECD TG 421.

(Details on test methods from website: OECD Guidelines for the Testing of Chemicals, Section 4 – Health Effects).

• Short or long term repeated dose toxicity studies that demonstrate reproductive toxicity in the absence of significant generalized toxicity (for example, histopathological changes in the gonads) can be used as a basis for classification (GHS, seventh revised edition, 2017 paragraph 3.7.2.5.3). Toxicological effects observed in a standard repeat dose study could be considered valid for the pre-mating phase for adult females and the pre- and post-mating phases for adult males. A detailed assessment of toxicity in pregnant animals cannot be extrapolated from studies with non-pregnant animals. However, information from general toxicity studies might give an indication of the maternal toxicity that could be anticipated in a subsequent developmental toxicity study.
• In vitro assays, non-mammalian tests or structure-activity relationships can contribute to the classification (GHS, seventh revised edition, 2017 paragraph 3.7.2.5.4).
• Route of administration: Dermal, inhalation or oral routes of exposure in animal studies could relate to the potential route of exposure in humans for characterizing the hazardous properties of a substance with respect to reproductive toxicity in humans.
• Limit dose: In principle, adverse effects on reproduction seen only at very high dose levels in animal studies (for example, doses that induce prostration, severe loss of appetite, excessive mortality) would not normally support classification. Specification of the limit dose will depend upon the test method.

General Considerations (GHS, seventh revised edition, 2017, section 3.7.2.3)

There are factors, other than maternal toxicity, to consider when evaluating data for reproductive toxicity. Some of which are discussed below:

• Toxicokinetic studies: If it can be conclusively demonstrated that the mechanism or mode of action causing the reproductive toxicity has no relevance for humans, or when the toxicokinetic differences are so marked that it is certain that the hazardous property will not be expressed in humans, then the substance should not be classified based on those factors (refer to the discussion of subsection 2(9) in Part 2 of this guidance).
• Effects of low or minimal toxicological significance: These effects could include small changes in semen parameters or in the incidence of spontaneous defects in the fetus, small changes in the proportions of common fetal variants such as are observed in skeletal examinations, or in fetal weights, or small differences in postnatal developmental assessments. Such effects may not be sufficient for classification.

Maternal Toxicity (GHS, seventh revised edition, 2017, section 3.7.2.4)

Maternal toxicity may influence the development of the embryo, fetus or offspring via non-specific secondary mechanisms, producing effects such as depressed fetal weight, retarded ossification, and possibly resorptions and certain malformations. When evaluating observations of developmental toxicity in the presence of maternal toxicity, the preferred approach is to consider adverse effects in the embryo or fetus first and then maternal toxicity.

The presence of maternal toxicity cannot be used to negate adverse effects on development of the embryo, fetus or offspring unless it can be clearly demonstrated that the effects are secondary to maternal toxicity, especially when the effects in the offspring are significant (for example, irreversible effects such as structural malformations, embryo/fetal lethality and significant postnatal functional deficiencies). In other words, when maternal toxicity is not severe and it cannot be shown to have a causal relationship to the adverse developmental effects on the offspring, classification in Reproductive Toxicity — Category 1 must be considered. When there is mechanistic information that raises doubt about the relevance of the effect for humans, classification in Reproductive Toxicity — Category 2 must be considered instead.

Some of the endpoints used to assess maternal toxicity are provided below. Data on these endpoints, if available, need to be evaluated in light of their statistical or biological significance and dose response relationship.

1. Maternal mortality: an increased incidence of mortality among the treated dams over the controls should be considered evidence of maternal toxicity if the increase occurs in a dose-related manner and can be attributed to the systemic toxicity of the test material. Maternal mortality greater than 10% is considered excessive and the data for that dose level should not normally be considered for further evaluation.
2. Mating index (N° animals with seminal plugs or sperm/N° mated × 100)
3. Fertility index (N° animals with implants/N° of matings × 100)
4. Gestation length (if allowed to deliver)
5. Body weight and body weight change: consideration of the maternal body weight change and/or adjusted (corrected) maternal body weight should be included in the evaluation of maternal toxicity whenever such data are available. The calculation of an adjusted (corrected) mean maternal body weight change, which is the difference between the initial and terminal body weight minus the gravid uterine weight (or alternatively, the sum of the weights of the fetuses), may indicate whether the effect is maternal or intrauterine. For example, a significant reduction in maternal body weight gain throughout gestation, without a concomitant change in corrected maternal weight gain, would indicate an intrauterine effect in the absence of maternal toxicity. In rabbits, the body weight gain may not be a useful indicator of maternal toxicity because of normal fluctuations in body weight during pregnancy.
6. Food and water consumption (if relevant): the observation of a significant decrease in the average food or water consumption in treated dams compared to the control group may be useful in evaluating maternal toxicity, particularly when the test material is administered in the diet or drinking water. Changes in food or water consumption should be evaluated in conjunction with maternal body weights when determining if the effects noted are reflective of maternal toxicity or more simply, unpalatability of the test material in feed or water.
7. Clinical evaluations (including clinical signs, markers, haematology and clinical chemistry studies): The observation of increased incidence of significant clinical signs of toxicity in treated dams relative to the control group may be useful in evaluating maternal toxicity. If this is to be used as the basis for the assessment of maternal toxicity, the types, incidence, degree and duration of clinical signs should be reported in the study. Examples of clinical signs of maternal intoxication include coma, prostration, hyperactivity, loss of righting reflex, ataxia, or laboured breathing.
8. Post-mortem data: increased incidence and/or severity of post-mortem findings may be indicative of maternal toxicity. This can include gross or microscopic pathological findings or organ weight data, for example, absolute organ weight, organ-to-body weight ratio, or organ-to-brain weight ratio. When supported by findings of adverse histopathological effects in the affected organ(s), the observation of a significant change in the average weight of suspected target organ(s) of treated dams, compared to those in the control group, may be considered evidence of maternal toxicity.

Note that for classification purposes, the known induction of genetically based inheritable effects in the offspring is more appropriately addressed in Germ Cell Mutagenicity. (GHS, seventh revised edition, 2017, section 3.7.1.1)

Discussion of subsection 8.7.1(2) of the Hazardous Products Regulations

Effects on or via lactation are allocated to a separate single category and must be evaluated independently of the adverse effects covered in subsection 8.7.1(1) of the HPR.

As defined in section 8.7 of the HPR, effects on or via lactation means:

1. (a) any effect of a mixture or substance that interferes with lactation; or
2. (b) the mixture or substance (including metabolites) is present in breast milk in amounts for which there is evidence that supports the conclusion, based on established scientific principles, that the health of the breast-fed child or suckling animal is liable to be threatened.

If a substance causes marked, overt, systemic maternal toxicity at the same dose level as it interferes with lactation, then it is possible that the maternal toxicity may indirectly impair milk production or impair maternal care as a non-specific secondary effect. If there is evidence to indicate that the effects on lactation are not caused directly by the substance then it must not be classified as such. A substance which does not cause overt toxicity in the mother but which interferes with milk production or quality will normally be classified for effects on or via lactation because, in this case, the effect on lactation is most likely a direct substance-related effect.

When the effect on the offspring is caused by the substance (or metabolite) after transport through the milk, then maternal toxicity has no relevance for classification.

In exceptional circumstances, if there are substantiated grounds for concern that the substance may have an adverse effect via lactation then it may be classified as such in the absence of direct evidence. This determination should be based on a quantitative comparison of the estimated transfer of the substance via the milk and the threshold for toxicity in the offspring. This situation might apply in cases:

• where the substance has the capacity to bioaccumulate, which would lead to a potentially higher burden in the offspring, or
• where there is evidence that the offspring may be more sensitive to the substance's toxicity than adult.

The mere presence of the substance in the milk alone, without a justification for a concern to offspring, would normally not support classification for effects on or via lactation (ECHA Guidance, 2017, p. 404).

Classification in Reproductive Toxicity — Effects on or via Lactation can be assigned on the basis of human or animal data meeting 1 or more of the following conditions:

a) absorption, metabolism, distribution, and excretion studies which indicate the likelihood that the substance would be present in potentially toxic levels in breast milk: The implicit assumption behind this condition is that the offspring may receive a body burden of the substance (or metabolite) through suckling that is sufficient to cause toxicity.

The toxicokinetics of a substance and the likelihood that it will enter the breast milk may be predicted on the basis of the physico-chemical properties of the substance (for example, using characteristics such as pKa, logP, water solubility, and molecular weight) and this information could be used as part of the argument outlined above.

The potential of a substance to bioaccumulate following repeated exposure may also contribute to the body burden in the offspring. Studies where the offspring/neonates have extended exposure, such as multi-generation studies, implicitly allow for bioaccumulation.

There may be toxicokinetic and toxicodynamic reasons why neonates may potentially be more or less vulnerable to a particular adverse effect than adults. In the absence of any reliable information, it should be assumed that neonates and adults are equivalent in terms of sensitivity to the substance.

Overall, classification for effects on or via lactation can be assigned on the basis of toxicokinetic data or a well substantiated estimate of the exposure through the milk alone, provided that it is supported by an argument clearly justifying that the level present in the breast milk would be likely to harm developing offspring.

b) results of one or two generation studies in animals which provide clear evidence of adverse effect in the offspring due to transfer in the milk or adverse effect on the quality of the milk: These studies directly observe the offspring during lactation and any adverse effects that can be directly observed and quantified, such as deaths, decreased viability, or clinical signs such as reduced body weight gain etc. However, it must be considered whether these effects in the offspring are due to a direct adverse effect on lactation, or are due to impaired nursing behaviour which is a non-specific secondary consequence of maternal toxicity. If the impaired nursing behaviour is proven to be a substance-related specific effect on behaviour, then classification may be appropriate. It is also important to note that some developmental effects resulting from exposure in utero would only manifest post-natally, and these effects should not be used for classification. Cross-fostering studies, where available, may help establish whether effects are due to in utero or lactational exposure.

If there is sufficient data indicating that animal results are not relevant to humans, they should not be taken into account (refer to the discussion of subsection 2(9) in Part 2 of this guidance).

c) human evidence indicating a hazard to babies during the lactation period: Human observations of adverse effects in breastfed babies of mothers exposed to a substance provide clear evidence supporting classification. However, in practice, useful human data are rare due to the nature of the endpoint. More likely available are survey type studies which measure the levels of the substance in breast milk. Such studies may provide useful information on the potential for maternal exposure and the presence of the substance in the breast milk. Therefore, these studies may be of use in assessing the need for classification.

(ECHA Guidance, 2017, pp. 405-406) (GHS, seventh revised edition, 2017, Figure 3.7.1(b))

Classification of Mixtures

Discussion of section 8.7.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for reproductive toxicity, which means that the procedures described in sections 8.7.3 to 8.7.6 of the HPR must be followed in the order in which these sections appear in the HPR.

As specified in sections 8.7.3, 8.7.4, and 8.7.5 of the HPR classification of mixtures is based on evaluation of the individual ingredients of the mixture using concentration cut-off values for the ingredients classified in Reproductive Toxicity. However, if there are test data for the mixture as a whole, these data may be used to classify the mixture, instead of data on the individual ingredients. Finally, section 8.7.6 of the HPR specifies which bridging principles may be applied to the Reproductive Toxicity hazard class.

Two evaluations for classification of the mixture must be done. The mixture must be assessed for adverse effects on sexual function and fertility or adverse effects on development. The mixture must also be assessed for effects on or via lactation.

Therefore, a substance or mixture could be classified in Reproductive Toxicity — Category 1A, 1B, or 2 and in Reproductive Toxicity — Effects on or via Lactation.

Discussion of section 8.7.3 of the Hazardous Products Regulations

Subject to paragraphs 8.7.3(1)(a) and (b) of the HPR, subsection 8.7.3(1) of the HPR specifies that, if a mixture contains at least 1 ingredient that is classified in Reproductive Toxicity — Category 1A and the ingredient is present at a concentration of ≥ 0.1%, then the mixture must be classified in Reproductive Toxicity — Category 1 or Reproductive Toxicity — Category 1A.

Subject to paragraphs 8.7.3(2)(a) and (b) of the HPR, subsection 8.7.3(2) of the HPR specifies that, if a mixture contains at least one ingredient that is classified in Reproductive Toxicity — Category 1B and the ingredient is present at a concentration of ≥ 0.1%, and the mixture does not contain a Category 1A ingredient at a concentration of ≥ 0.1%, then the mixture must be classified in Reproductive Toxicity — Category 1 or Reproductive Toxicity — Category 1B.

Note that, as specified in paragraph 3(5)(o) of the HPR, the symbol, signal word, hazard statement and precautionary statements are the same for Reproductive Toxicity — Category 1, 1A and 1B.

The additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Reproductive Toxicity — Category 1A or 1B are not to be added together, and the sum of the concentration of those ingredients is not to be compared to the 0.1% concentration cut-off.

If there are data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that, as the concentration of a reproductive toxicant is reduced in a mixture the dilution effect may result in a misleading test result (that is, false negative) if the study was not appropriately designed to factor in the concentration of the reproductive toxicant in the mixture (OSHA Hazard Classification Guidance 2016, p. 179).

Therefore, the test results for the mixture as a whole must be shown to be conclusive taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation and analysis of reproduction test systems (GHS, seventh revised edition, 2017, section 3.7.3.1). If the results for the mixture as a whole are deemed relevant and conclusive, and meet the criteria for Reproductive Toxicity in accordance with subsection 8.7.1(1) of the HPR, the results must be applied to classify the mixture as a reproductive toxicant.

If the results for the mixture as a whole demonstrate that the mixture is not a reproductive toxicant, based on a reproductive toxicity study that was performed according to generally accepted standards of good scientific practice, and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified in Reproductive Toxicity — Category 1, even when Category 1A or 1B reproductive toxicant ingredients are present at or above the established cut-off concentration of 0.1%.

Discussion of section 8.7.4 of the Hazardous Products Regulations

If at least 1 ingredient present in the mixture at a concentration of ≥ 0.1% is classified in Reproductive Toxicity — Category 2, then the mixture is classified in Reproductive Toxicity — Category 2. Note that the additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Reproductive Toxicity — Category 2 are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 0.1% concentration cut-off.

If there are test data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that as the concentration of a reproductive toxicant is reduced in a mixture the dilution effect may result in a misleading test result (that is, false negative) if the study was not appropriately designed to factor in the concentration of the reproductive toxicant in the mixture (OSHA Hazard Classification Guidance 2016, p. 179).

Therefore, the test results for the mixture as a whole must be shown to be conclusive taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation and analysis of reproduction test systems (GHS, seventh revised edition, 2017, section 3.7.3.1). If the results for the mixture as a whole are relevant and conclusive, and meet the criteria for Reproductive Toxicity in accordance with subsection 8.7.1(1) of the HPR, the results must be applied to classify the mixture as a reproductive toxicant.

If the results for the mixture as a whole demonstrate that the mixture is not a reproductive toxicant, based on a reproductive toxicity study that was performed according to generally accepted standards of good scientific practice, and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified in Reproductive Toxicity — Category 2, even when Category 2 reproductive toxicant ingredients are present at or above the established cut-off concentration of 0.1%.

Discussion of subsection 8.7.5(1) of the Hazardous Products Regulations

If at least 1 ingredient present in the mixture at a concentration of ≥ 0.1% is classified in Reproductive Toxicity — Effects on or via Lactation, then the mixture is classified in Reproductive Toxicity — Effects on or via Lactation. Note that the additive approach is not applied to this hazard class. That is, the concentrations of individual ingredients that fall into Reproductive Toxicity — Effects on or via Lactation are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 0.1% concentration cut-off.

If there are test data available for the mixture as a whole, these data may be used instead of data on the individual ingredients to classify the mixture. The concern with using test data for the mixture as a whole is that as the concentration of a reproductive toxicant is reduced in a mixture the dilution effect may result in a misleading test result (that is, false negative) if the study was not appropriately designed to factor in the concentration of the reproductive toxicant in the mixture (OSHA Hazard Classification Guidance 2016, p. 179).

Therefore, the test results for the mixture as a whole must be shown to be conclusive taking into account dose and other factors based on established scientific principles, such as duration of exposure, observation and analysis of effects on or via lactation (GHS, seventh revised edition, 2017, section 3.7.3.1). If the results for the mixture as a whole are relevant and conclusive, and meet the criteria for Reproductive Toxicity in accordance with subsection 8.7.1(2) of the HPR, the results must be applied to classify the mixture in Reproductive Toxicity — Effects on or via Lactation.

If the results for the mixture as a whole demonstrate that the mixture does not present effects on or via lactation based on a study that was performed according to generally accepted standards of good scientific practice, and a scientifically validated method was used, the results must be applied. That is, the mixture must not be classified in Reproductive Toxicity — Effects on or via Lactation, even when ingredients classified in Reproductive Toxicity — Effects on or via Lactation are present at or above the established cut-off concentration of 0.1%.

Discussion of subsection 8.7.5(2) of the Hazardous Products Regulations

This provision allows for dual classification within the same hazard class. A mixture may be classified as both Reproductive Toxicity — Category 1 or 2 and Reproductive Toxicity — Effects on or via Lactation. The mixture must be additionally and independently assessed for effects on or via lactation, regardless of whether the mixture has been classified in Category 1 or 2.

Discussion of section 8.7.6 of the Hazardous Products Regulations

For this hazard class, the use of bridging principles is the final step in the tiered approach for the classification of mixtures. When there is no or insufficient data on the ingredients or the mixture as a whole, bridging principles can be applied if there is sufficient data available on similar tested mixtures and on the individual hazardous ingredients within the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

Note that not all of the bridging principles apply to this hazard class. Only dilution, production batches, and substantially similar mixtures are applicable. Increase in concentration of hazardous ingredient, interpolation, and aerosols are not used for this hazard class.

If data on another mixture are used in the application of the bridging principles, the data on that mixture must be conclusive for the mixture as a whole, as discussed above under sections 8.7.3, 8.7.4 and 8.7.5 of the HPR.

Based on bridging principles, a mixture can be classified in Category 1, Category 2, Effects on or via Lactation, Category 1 and Effects on or via Lactation, or Category 2 and Effects on or via Lactation.

Hazard Communication

The symbol, signal words, hazard statements, and precautionary statements for Reproductive Toxicity Category 1 and Category 2 are specified in Section 3 of Annex 3 of the GHS, seventh revised edition, p. 357. Paragraph 3(5)(o) of the HPR specifies that if the hazardous product is classified in the subcategory Reproductive Toxicity — Category 1A or in the subcategory Reproductive Toxicity — Category 1B, the information elements specified for the category Reproductive Toxicity — Category 1 apply.

Note that the symbol and precautionary statements are the same for Category 1 and Category 2; the signal word and hazard statement are different between the 2 categories.

As part of the hazard statement, the specific effect must be specified, if known (that is, impairment of sexual function and fertility or developmental toxicity). However, it may be difficult to differentiate adverse effects on sexual function and fertility compared to developmental toxicity. Where the effect cannot be clearly differentiated, the general hazard statement for Category 1 or 2, as applicable, must be applied (ECHA Guidance, 2017, p. 423).

Also as part of the hazard statement, the route of exposure must be specified if it has been conclusively proven that no other routes of exposure cause the effect. In order to be able to specify the route of exposure, test data need to be available for all 3 relevant routes (oral, dermal and inhalation), and the data must clearly indicate that only one route leads to positive results. It is estimated that such circumstances rarely, if ever, exist (ECHA Guidance, 2017, p. 424)

The hazard and precautionary statements for Reproductive Toxicity — Effects on or via Lactation are specified in Section 3 of Annex 3 of the GHS, seventh revised edition, p. 358. There is no symbol or signal word associated with this classification.

Classification of Reproductive Toxicity for Substances Examples

(OSHA Hazard Classification Guidance 2016, p. 186)

Example 8.7.1:

Available data

Substance X was tested for reproductive toxicity using OECD TG 415. There was a statistically significant decrease in the number of fetuses per litter, a significant decline in the ability of males to impregnate females, and a significant increased incidence of preimplantation embryo deaths. Effects were dose-dependent and without observations of general toxicity.

Classification

Reproductive Toxicity — Category 1B

Rationale

The test result fulfills Item 2 (a) of subsection 8.7.1(1) of the HPR – clear evidence of an adverse effect in experimental animals.

Example 8.7.2:

Available data

Human epidemiological studies describe increased incidence of natural abortion after exposure, abnormal development and malformation of newborns caused by prenatal abuse, and decreased plasma concentrations of luteinizing hormone and testosterone after exposure.

Increased risk of late spontaneous abortions associated with exposure at levels around 88 ppm (range 50-150 ppm).

Evidence of increased incidences of fetal death and delayed ossification, a decrease and unossification of sternebrae, a shift in rib profile, excess ribs, retarded skeletal development, delayed reflex response, learning disability, and early vaginal opening and testes descent at dose levels not toxic to dams from rat and mouse teratogenicity tests.

Classification

Reproductive Toxicity — Category 1A

Rationale

The test result fulfills Item 1 of subsection 8.7.1(1) of the HPR – clear evidence of an adverse effect in humans (supported by adverse effects in experimental animals). Note that the evidence regarding adverse effects in experimental animals is useful, but not necessary, to support classification in Category 1A.

Classification of Reproductive Toxicity for Mixtures Example

(OSHA Hazard Classification Guidance 2016, p. 187)

Example 8.7.3:

Available data

Table 8.26 Classification of Reproductive Toxicity for mixtures based on the concentration of the components.

Component	Concentration (w/w)%	Classification
A	0.05	Reproductive Toxicity — Category 1B
B	97.75	Not Classified
C	2	Reproductive Toxicity — Category 2
D	0.2	Reproductive Toxicity — Effects on or via Lactation

Data for the mixture as a whole is not available.

Classification

Reproductive Toxicity — Category 2 and Reproductive Toxicity — Effects on or via Lactation

Rationale

Component B is not classified for Reproductive Toxicity therefore is not considered when classifying the mixture.

Component A falls below the 0.1% cut-off value for Category 1 and has not been shown to cause reproductive effects below this concentration, therefore it is not considered when classifying.

Component C is ≥ 0.1%, and therefore meets Category 2 criteria for the mixture.

Component D is ≥ 0.1%, and therefore meets Effects on or via Lactation criteria for the mixture.

Subpart 8 Specific Target Organ Toxicity — Single Exposure

Discussion – Specific Target Organ Toxicity Arising From a Single Exposure (STOT-SE)

The Specific Target Organ Toxicity (STOT) classification addresses substances or mixtures that affect target organ systems of the body after either single or repeated exposure by any route (oral, dermal or inhalation) that is relevant for human exposure. The HPR addresses 2 different types of STOT hazards: toxicity that occurs after a single exposure (STOT–SE), and toxicity that occurs after repeated exposures (STOT-RE). STOT-RE is addressed in Subpart 9 of Part 8 of the HPR.

For STOT-SE, substances and mixtures can be classified in more than one hazard category. Subsection 2(2) of the HPR specifies that, if a product, mixture, material or substance meets the criteria for a more severe hazard category of a hazard class (for example, Category 1 for most hazard classes), it must be classified in that category and does not need to be further evaluated against the criteria for another less severe hazard category within the same classification table of the same hazard class.

The STOT-SE hazard class does not follow this rule. As specified in subsections 8.8.1(1) and (2) of the HPR, there are three hazard categories and, for the purposes of classification, a substance or mixture must be evaluated against the criteria for all 3 categories. It is, therefore, possible to have a substance or mixture that is classified in the following category(ies) of this hazard class (see discussion of subsection 8.8.1(1) of the HPR and discussion of subsection 8.8.1(2) of the HPR below):

• STOT-SE — Category 1, Category 2, or Category 3,
• STOT-SE — Category 1 and Category 3, or
• STOT-SE — Category 2 and Category 3.

Subsection 2.2(3) of the HPR specifies that, except in the case of Subparts 1, 4, 7 and 8 of Part 8 (Acute Toxicity, Respiratory or Skin Sensitization, Reproductive Toxicity and STOT-SE, respectively), the first provision that results in a mixture being classified in a category or subcategory of a health hazard class concludes the process of classification with regard to that particular health hazard class. No further evaluation of the mixture in relation to the remaining provisions for the classification of mixtures in that health hazard class is necessary.

For STOT-SE, a supplier must evaluate the data for a mixture against the criteria for all 3 hazard categories and then follow the criteria in the table to subsection 8.8.1(2) of the HPR to determine the resulting classification (see discussion of subsection 8.8.1(2) of the HPR below).

Definitions

Narcotic Effects

Narcotic effects may range from slight dizziness to deep unconsciousness and may be caused by, for example, organic industrial chemicals (such as solvent vapours) which may have unspecific effects on central nervous system (CNS)-membranes, organic chemicals with similarities to and interference with CNS-transmitters (for example, solvents such as butandiol, butyrolactone, methoxyethanol), or chemicals with high specific CNS toxicity or narcotic effects close to near-lethal doses (for example, hydrogen sulphide).

Narcotic effects are typically reversible upon cessation of exposure causing no permanent changes or damages (ECHA Guidance, 2017, section 3.8.2.4.1).

Organ

An organ is a part of the body that carries out one or more special functions. Examples of organs include lungs, liver, eyes, blood and the central nervous system.

Respiratory Tract Irritation

The respiratory tract consists of the air passages from the nose to the air sacs of the lungs, including the pharynx, larynx, trachea, and bronchi.

The generic term "respiratory tract irritation" covers 2 different effects: sensory irritation and local cytotoxic effects. Sensory irritation refers to the local and central reflex interaction of a substance with the autonomic nerve receptors, which are widely distributed in the mucosal tissues of the eyes and upper respiratory tract. Sensory irritation-related effects are fully reversible given that the biological function of the autonomic nerve receptors is to serve as a warning against substances that could damage the airways. Local cytotoxic effects induce tissue changes at the site of contact. Such effects may induce long lasting functional impairment of the respiratory system (ECHA Guidance, 2017, section 3.8.2.3). For the purposes of the HPR, "respiratory tract irritation" is limited to local cytotoxic effects, since "respiratory tract irritation" refers to "localized redness, edema, pruritis or irritant effects in the respiratory tract that impair its function, whether or not accompanied by cough, pain, choking, breathing difficulties or other respiratory symptoms".

Specific target organ toxicity arising from a single exposure versus other health hazard classes

Classification in STOT-SE is assigned only when specific, non-lethal toxic effects on target organs that arise from a single exposure are observed and another health hazard class in the HPR does not address the observed toxicity. For example, substances and mixtures that cause skin corrosion from a single exposure must be classified in Skin Corrosion — Category 1, not in STOT-SE.

STOT-RE is not included in the list of other health hazard classes that must be considered before a classification in STOT-SE is assigned because this hazard class applies to target organ toxicity that arises from a repeated exposure, not a single exposure. Therefore, a substance can be classified in both STOT-SE and STOT-RE, if the respective criteria are met.

Acute Toxicity addresses lethal toxic effects and STOT-SE addresses non-lethal specific target organ toxic effects. Therefore, a substance could be classified in both the Acute Toxicity and STOT-SE hazard classes, if the respective criteria are met. However, the substance must not be assigned to both hazard classes (Acute Toxicity and STOT-SE) for the same effect. In such a case, the most severe hazard class (Acute Toxicity) must be assigned. Classification in STOT-SE is only warranted where there is data available for specific organ toxicity, and the effects are non-lethal.

Examples can be found in the United Nations Sub-Committee of Experts on the GHS's Guidance on the application of GHS criteria to help illustrate this concept. In particular, there are examples for when:

• A substance should be classified in the Acute Toxicity hazard class but not STOT-SE
• A substance should be classified into both STOT-SE, for non-lethal effects, and the Acute Toxicity hazard class for lethal effects

Classification in a category of the class

Classification of substances

Discussion of subsection 8.8.1(1) of the Hazardous Products Regulations

The hazard class STOT-SE has 3 categories. Categories 1 and 2 are very distinct from Category 3.

The data required to evaluate STOT-SE for Category 1 and 2 is based on specific target organ toxicity arising from single exposure in humans or from studies conducted in experimental animals. The data from standard animal (that is, rats or mice) studies, such as acute toxicity studies which include details on clinical observations and/or macroscopic and microscopic examination, are acceptable for classification in STOT-SE. Data from acute toxicity studies conducted in other species are also acceptable provided that these data provide relevant information on toxic effects on target organs/tissues (GHS, seventh revised edition, 2017, paragraph 3.8.2.1.5).

Category 3 covers "transient effects" occurring after a single exposure, specifically respiratory tract irritation and narcotic effects. These are target organ effects for which the available data for a substance does not meet the criteria for Category 1 or 2. They are effects which alter function for a short duration after exposure but are essentially reversible upon cessation of exposure with no permanent damage or changes to the respiratory tract or central nervous system.

STOT-SE ─ Category 1 or Category 2

The dose or concentration at which effects are produced in animal studies needs to be considered to determine relevance for humans. Therefore, concentration value ranges have been established for Category 1 and Category 2. These concentration value ranges are only applied when classifying based on animal data. The comparison to the specified concentration value ranges provides the necessary information to assign classification in the appropriate category.

The concentration value ranges from Table 3.8.1 of the GHS are reproduced in the Table 8.27 below.

There are no corresponding concentration value ranges for human data. Positive human data, regardless of probable dose, predominates over animal data (GHS, seventh revised edition, 2017, paragraph 3.8.2.1.10.2). A substance with well-substantiated human data showing a specific target organ toxic effect after a single exposure at very high doses must be classified in Category 1 even if there are animal data available which do not show toxicity at or below the established concentration value ranges. Similarly, there are no concentration value ranges for STOT-SE — Category 3 since classification in this category is typically based on human data.

Table 8.27 Concentration value ranges for single-dose exposures (GHS, seventh revised edition, 2017, Table 3.8.1)

		Concentration value ranges for:
Route of exposure	Units	Category 1	Category 2
Oral (rat)	mg/kg body weight	C ≤ 300	2000 ≥ C > 300
Dermal (rat or rabbit)	mg/kg body weight	C ≤ 1000	2000 ≥ C > 1000
Inhalation (rat) gas	ppm V/4h	C ≤ 2500	20000 ≥ C > 2500
Inhalation (rat) vapour	mg/litre/4h	C ≤ 10	20 ≥ C > 10
Inhalation (rat) dust/mist/fume	mg/litre/4h	C ≤ 1.0	5.0 ≥ C > 1.0

Note: In the case of inhalation studies with exposure times other than 4 hours, an extrapolation to 4 hours can be performed.

If a substance meets the classification criteria for Category 1 for one route of exposure and Category 2 for another, the substance is only classified in Category 1, as required by subsection 2(2). The relevant route(s) of exposure (oral, dermal and/or inhalation) by which the substance causes specific target organ effects must be disclosed in section 11 of the SDS. In addition, if there is only one relevant route of exposure and it is conclusively proven that no other routes cause the hazard, then the relevant route of exposure (oral, dermal or inhalation) must be specified in the hazard statement provided on the label and in section 2 of the SDS.

Evaluating target organ toxicity

As described in the GHS (seventh revised edition, 2017, paragraph 3.8.2.1.7.3), the following are examples of relevant toxic effects in humans and/or animals considered to support classification in Category 1 or 2:

1. Morbidity resulting from single exposure;
2. Significant functional changes, more than transient in nature, in the respiratory system and in the central or peripheral nervous systems or other organs or other organ systems, including signs of central nervous system depression and effects on special senses (for example, sight, hearing and sense of smell);
3. Any consistent and significant adverse change in clinical biochemistry, hematology, or urinalysis parameters;
4. Significant organ damage noted at necropsy and/or subsequently seen or confirmed at microscopic examination;
5. Multi-focal or diffuse necrosis, fibrosis or granuloma formation in vital organs with regenerative capacity;
6. Morphological changes that are potentially reversible but provide clear evidence of marked organ dysfunction (for example, severe fatty change in the liver). Adaptive changes or changes in organ weights with no evidence of organ dysfunction do not support classification; and
7. Evidence of appreciable cell death (including cell degeneration and reduced cell number) in vital organs incapable of regeneration.

As described in the GHS (seventh revised edition, 2017, paragraph 3.8.2.1.8), the following are examples of effects that may be seen in humans and/or animals that would not support classification in Category 1 or 2:

1. Clinical observations or small changes in bodyweight gain, food consumption or water intake that may have some toxicological importance but that do not, by themselves, indicate "significant" toxicity;
2. Small changes in clinical biochemistry, hematology or urinalysis parameters and/or transient effects, when such changes or effects are of doubtful or of minimal toxicological importance;
3. Changes in organ weights with no evidence of organ dysfunction;
4. Adaptive responses that are not considered toxicologically relevant; and,
5. Substance-induced species-specific mechanisms of toxicity, that is, demonstrated with reasonable certainty to be not relevant for human health (subsection 2(9) of the HPR).

It is important to note that for STOT-SE, the primary target organ(s) must be identified for the evaluation of toxicity; organs in which secondary effects were observed should not be included. For example, in the case of a hepatotoxicant, data on the secondary effects that it produces in the nervous or gastro-intestinal systems should not be included in the evaluation of classification.

STOT-SE — Category 3

Classification in STOT- SE — Category 3 (respiratory tract irritation or narcotic effects) is primarily based on human data, such as occupational case reports. However, animal data can also be included in the assessment.

There must be a clear relationship between exposure and the development of signs of respiratory irritation, with respiratory irritation appearing relatively soon after the start of exposure. Symptoms of function impairment in humans could include cough, pain, choking, and breathing difficulties.

Symptoms observed in humans must be representative of those seen in the general population, rather than only in individuals with hypersensitive airways (for example, asthma patients).

Ambiguous reports of "irritation" must be excluded as the term is commonly used to describe a wide range of sensations. Subjective human observations must be supported by objective measurements of clear respiratory tract irritation (for example, electrophysiological responses or biomarkers of inflammation) (GHS, seventh revised edition, 2017, paragraph 3.8.2.2.1).

Clinical signs of respiratory tract irritation in animals could include dyspnea and rhinitis. Histopathology indicative of respiratory tract irritation in animals could include hyperemia, edema, minimal inflammation and thickened mucous layer (GHS, seventh revised edition, 2017, paragraph 3.8.2.2.1).

Generally, animal data for respiratory tract irritation and/or narcotic effects would be observed from acute inhalation studies where reversible clinical signs of toxicity and histopathology could be used to support classification. However, narcosis could be observed in studies with other routes of exposure (dermal and/or oral) and these observations must also be considered for classification of a substance in STOT-SE — Category 3 (narcotic effects).

Note: A solid substance which causes respiratory tract irritation due to physical or mechanical irritation when inhaled as a dust must not be considered for classification in Category 3 (respiratory irritation) (ECHA Guidance, 2017, section 3.8.2.4.1).

Structure-Activity Relationships

A substance that has not been tested for specific target organ toxicity may, in certain instances, be classified in STOT-SE — Category 1, 2, or 3 on the basis of data from a validated structure activity relationship or extrapolation results from a structural analogue that has previously been classified in STOT-SE. This information, together with substantial support from other important factors such as formation of common significant metabolites could result in classification (GHS, seventh revised edition, 2017, paragraph 3.8.2.1.10.3). The potential use of (Q)SAR models for predicting effects relevant to STOT-SE — Category 1 and 2 is currently quite limited and may only be applicable in specific cases. However, they may be useful for STOT-SE — Category 3 where there are some well established relationships between physicochemical properties or chemical structure and narcosis and respiratory tract irritation. For instance, substances such as aldehydes, unsaturated carbonic esters and reactive inorganic compounds are generally found to be respiratory tract irritants (ECHA Guidance, 2017, section 3.8.2.1.2).

Discussion of subsection 8.8.1(2) of the Hazardous Products Regulations

Since a substance is assessed for effects on other specific target organs (Category 1 or 2) and specific effects on the central nervous system and respiratory tract (Category 3) separately, 2 classifications may result. Table 8.28 - Decision on classification of substances provides the appropriate classification of a substance using the results from the initial evaluations for the CNS and respiratory tract and, toxic effects on other specific target organs. If effects are observed in the CNS and/or respiratory tract which meet classification criteria in Category 1 or 2, further classification of any transient effects in these same organ systems meeting Category 3 criteria for the same endpoint is not necessary. If classification in Category 1 or 2 is based on effects observed in a target organ(s) other than the CNS or respiratory tract, any transient effects in the CNS or respiratory tract must also be considered for a possible Category 3 classification in addition to the established Category 1 or 2.

Examination of Table 8.28 - Decision on classification of substancesshows that if a substance meets the criteria:

• for Category 1 only, it must be classified as Category 1
• for Category 2 only, it must be classified as Category 2
• for both Category 1 and Category 2, it must be classified as Category 1; or
• for Category 3, it can be classified either as:
  • Category 3 alone, or
  • as part of classification with either Category 1 or Category 2 (that is, final classification would be Category 1 and Category 3, or Category 2 and Category 3, depending on the other classification that applies to the substance).

Table 8.28 Decision on classification of substances

Toxic Effects on the Central Nervous System and Respiratory Tract	Toxic Effects on Other Specific Target Organs	Overall STOT-SE Classification
None	Category 1	Category 1
Category 1	None	Category 1
Category 1	Category 1	Category 1
None	Category 2	Category 2
Category 2	None	Category 2
Category 1	Category 2	Category 1
Category 2	Category 1	Category 1
Category 2	Category 2	Category 2
Category 3 (transient respiratory tract irritation or narcotic effects)	None	Category 3
Category 3 (transient respiratory tract irritation or narcotic effects)	Category 1	Category 1 and Category 3
Category 3 (transient respiratory tract irritation or narcotic effects)	Category 2	Category 2 and Category 3

Classification of mixtures

Discussion of section 8.8.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for STOT-SE, which means that the procedures described in sections 8.8.3 to 8.8.5 of the HPR must be followed in the order in which these sections appear in the HPR. As specified in section 8.8.3 of the HPR, if there are test data for the mixture as a whole, these data may be used to classify the mixture. Section 8.8.4 of the HPR specifies which bridging principles may be applied to the STOT-SE hazard class. Finally, section 8.8.5 of the HPR specifies that classification of mixtures for STOT-SE is based on the evaluation of available test data for the individual ingredients of the mixture and includes the use of concentration cut-off values for the ingredients classified in this hazard class.

Discussion of section 8.8.3 of the Hazardous Products Regulations

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is the same as for substances, and is carried out according to section 8.8.1 of the HPR. The discussion sections of this guidance corresponding to section 8.8.1 of the HPR, as well as the discussion section relating to the classification of substances in general (Part 2), are relevant to the classification of mixtures if there is data available for the mixture as a whole. The data available on the mixture as a whole must be compared to the classification criteria within each category. If the data available meets the criteria in section 8.8.1 of the HPR, then the mixture must be classified in the category for which the criteria are met. Care should be exercised in evaluating data on mixtures, that the dose, duration, observation or analysis do not render the results inconclusive (GHS, seventh revised edition, 2017, section 3.8.3.2).

Discussion of section 8.8.4 of the Hazardous Products Regulations

For this hazard class, the use of bridging principles is the second step in the tiered approach for the classification of mixtures.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in subsections 2.3(1) to 2.3(8) of the HPR.

All of the bridging principles are applicable to the STOT-SE hazard class, namely: dilution, production batches, increase in concentration of hazardous ingredient, interpolation, substantially similar mixtures, and aerosols.

Discussion of subsection 8.8.5(1) of the Hazardous Products Regulations

Following application of 8.8.3 and 8.8.4 of the HPR, if a classification for the mixture as a whole cannot be determined, data available for the ingredients of the mixture are considered as the final step in the tiered approach for the classification of mixtures in this hazard class.

Since Category 1 and 2 address different hazards than Category 3, the hazard assessment for these categories must be done independently.

For mixtures, a concentration limit of ≥1% has been established when determining Category 1 or Category 2 classification. If at least one ingredient present in the mixture at a concentration of ≥ 1% is classified as STOT-SE — Category 1 or 2, then the mixture is classified as STOT-SE — Category 1 or 2, as applicable.

As outlined below, for classification in Category 1 or 2 of STOT-SE, the additive approach is not applied. That is, the concentrations of individual ingredients that fall into STOT- SE — Category 1 or 2 are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 1% concentration cut-off. However, for classification in Category 3 according to subparagraphs 8.8.5(1)(c)(ii), 8.8.5(1)(d)(i) and 8.8.5(1)(d)(ii) of the HPR, the additive approach is employed (see paragraph starting with "For Category 3 only, the additive approach must be applied"). According to subparagraph 8.8.5(1)(c)(i) of the HPR, if a mixture contains at least one ingredient that is classified as STOT-SE — Category 3 and the ingredient is present at a concentration equal to or greater than the concentration at which the effect is elicited, the mixture must be classified as STOT-SE — Category 3.

When classifying mixtures based on ingredient information, ingredients which demonstrate potentiation or synergistic interactions when combined must be considered (subsection 2.4(1) of the HPR). Ingredients that are present in the mixture at < 1% concentration and cause specific target organ toxicity when combined with potentiating ingredients must also be considered for classification.

A concentration limit of ≥ 20% has been established for determining classification in STOT-SE — Category 3. If the mixture contains an ingredient which meets classification criteria for STOT-SE ─ Category 3 at a concentration ≥ 20%, then the mixture must be classified as STOT-SE — Category 3.

For Category 3 only, the additive approach must be applied. Concentrations of the ingredients meeting the criteria for STOT-SE — Category 3 for the same hazard (respiratory tract irritation or narcotic effects) are summed up separately, that is, concentrations of ingredients that cause narcotic effects should not be added to the concentrations of ingredients that only cause respiratory tract irritation effects. Similarly concentrations of ingredients that cause respiratory tract irritation effects should not be added to the concentrations of ingredients that cause only narcotic effects. If either sum is ≥ 20%, then the mixture must be classified as Category 3 for that hazard.

Note: A mixture could be classified as Category 3 (respiratory tract irritation) or Category 3 (narcotic effects) or both.

Note: There are exceptions to the concentration limits established in 8.8.5(1) for classifying mixtures. Although concentration limits have been established in 8.8.5(1), when an ingredient presents the hazard at a concentration which is below the concentration limit, and the mixture contains the ingredient at or above that concentration, the mixture must be classified in the category for which it meets the criteria. Refer to the discussion of subsection 2.5(1) of the HPR in Part 2 of this guidance for details.

Discussion of subsection 8.8.5(2) of the Hazardous Products Regulations

Subsection 2.2(3) specifies that, once the mixture is classified, the provisions that follow do not apply. Classification of mixtures for STOT-SE, in accordance with subsection 8.8.5(2), is one of the exceptions to this provision. If criteria are met for classification in Category 1 or 2 and classification in Category 3, under subsection 8.8.5(1), the mixture must be classified in Category 1 and 3, or Category 2 and 3, as appropriate. The principles described in the discussion to subsection 8.8.1(2) above, for classifying substances in both Category 1 or 2 and Category 3, would apply.

Hazard communication

The symbols, signal words, hazard statements, and precautionary statements for STOT-SE Categories 1, 2 and 3 are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017, pp. 359-361.

Note: As part of the hazard statement, the route(s) of exposure must be specified if it has been conclusively proven that no other routes of exposure cause the effect. In order to be able to specify the route of exposure, test data need to be available for all 3 relevant routes (oral, dermal and inhalation) and the data must clearly indicate that only one route leads to positive results.

For both substances and mixtures, the hazard statement must include all organs affected, if known. Therefore, if the mixture is classified on the basis of information available for its ingredients, the target organs affected by the ingredients must be identified. This information must be provided on the SDS and label.

Classification of STOT-SE for substances examples

Example 8.8.1: Use of valid human evidence supported by animal data (ECHA Guidance, 2017, section 3.8.5.1.2)

Available data

1. Human data: There are well documented case reports of severe neurotoxic effects
2. Animal data: Severe neurotoxic effects (paralysis) were observed after single exposure to doses < 200 mg/kg bw. Rat oral LD₅₀ = 3000 – 3900 mg/kg bw

Classification

STOT-SE ─ Category 1

Rationale

The classification criteria are fulfilled based on human evidence as well as on results of animal studies at non-lethal doses.

Example 8.8.2: Use of valid animal data (ECHA Guidance, 2017, section 3.8.5.1.4)

Available data

1. Human data: not available
2. Animal data: In valid animal experiments, narcotic effects (transient effect on nervous system) at ≥ 8 mg/l were observed.

Classification

STOT-SE ─ Category 3 (Narcotic effects).

Rationale

The classification criteria for Category 3 (Narcotic Effects) are fulfilled based on well documented results in animal experiments.

Example 8.8.3: Use of valid animal data where same effect after single exposure leads to Acute Toxicity classification (ECHA Guidance, 2017, section 3.8.5.2.1)

Available data

• Human data: not available
• Animal data: In a study in rats, severe damage in liver (macroscopic examination) and mortality in 6/10 animals were observed after a single exposure to 2,000 mg/kg bw.

Classification

No classification in STOT-SE.

Rationale

Though a specific organ is damaged, the substance must be classified in Acute Toxicity (Category 4), since lethality due to the liver impairment was observed. It is assumed that the LD₅₀ is ≤ 2,000 mg/kg bw. There must not be a "double" classification for the same effect/mechanism causing lethality by impairment of a specific organ.

Classification of STOT-SE for mixtures example

Application of additivity approach

Example 8.8.4:

Available data

No test data with respect to STOT-SE are available for the mixture as a whole.

Bridging principles cannot be applied, since no respective test data on a similar mixture are available.

Table 8.29 Classification of STOT-SE for mixtures based on the ingredients.

Ingredient	Concentration (%w/w)	Classification
1	0.5	Not Classified
2	3.5	STOT-SE — Category 3 (Respiratory tract irritation)
3	15	STOT-SE — Category 3 (Narcotic effects)
4	15	STOT-SE — Category 3 (Narcotic effects)
5	66	Not Classified

Classification

STOT-SE — Category 3 (Narcotic effects)

Rationale

The sum of ingredients (weight/weight %) classified as Category 3 (Narcotic effects) is 15% + 15% = 30%, which is ≥ 20%. Therefore, the mixture is classified as Category 3 (Narcotic effects).

The sum of ingredients (weight/weight %) classified as Category 3 (Respiratory tract irritation) is 3.5%, which is < 20%. Therefore, the mixture is not classified in Category 3 (Respiratory tract irritation).

Subpart 9 Specific Target Organ Toxicity — Repeated Exposure

Discussion – Specific Target Organ Toxicity Arising From Repeated Exposure (STOT-RE)

The Specific Target Organ Toxicity (STOT) classification addresses substances and mixtures that affect target organ systems of the body after either single or repeated exposure by any route (oral, dermal or inhalation) that is relevant for human exposure. The HPR addresses 2 different types of STOT hazards: toxicity that occurs after a single exposure (STOT–SE), and toxicity that occurs after repeated exposures (STOT-RE) to a substance or mixture. STOT-SE is addressed in Subpart 8 of Part 8 of the HPR.

Organ

An organ is a part of the body that carries out one or more special functions. Examples of organs include lungs, liver, eyes, blood and the central nervous system.

Specific target organ toxicity arising from repeated exposure

STOT-RE includes specific toxic effects on target organs that arise from repeated exposure to a substance or mixture, including those that can impair function of the body or any of its parts, both reversible or irreversible, immediate or delayed. Classification in STOT-RE is assigned only when specific toxic effects on target organs that arise from repeated exposure are observed and another health hazard class in the HPR does not address the observed toxicity. For example, a substance or mixture that causes skin sensitization following repeated exposure must be classified as a Skin Sensitizer — Category 1, 1A or 1B, as appropriate, rather than in STOT-RE. However, studies that support the classification of a substance or mixture in another health hazard class must be considered in the assessment of classification for STOT-RE if they also provide evidence of specific target organ toxicity following repeated exposure.

STOT-SE is not included in the list of other health hazard classes that must be considered before a classification in STOT-RE is assigned because this hazard class applies to target organ toxicity that arises from a single exposure, not a repeated exposure. Therefore, a substance can be classified in both STOT-RE and STOT-SE, if the respective criteria are met.

An example can be found in the United Nations Sub-Committee of Experts on the GHS's Guidance on the application of GHS criteria to help illustrate this concept. In particular, there is an example for when:

• A substance should be classified into STOT-RE, STOT-SE, and the Acute Toxicity hazard class

Classification in a Category of the Class

Classification of Substances

Discussion of section 8.9.1 of the Hazardous Products Regulations

The hazard class STOT-RE has 2 categories. The data required to evaluate STOT-RE for Category 1 and 2 comes either from repeated exposure in humans or from studies conducted in experimental animals. Toxicity can occur by any route that is relevant for humans (oral, dermal or inhalation). If a substance meets the classification criteria for Category 1 for one route of exposure and Category 2 for another, the substance must only be classified in Category 1, as required by subsection 2(2) of the HPR. The relevant route(s) of exposure by which the substance causes specific target organ effects must be disclosed in section 11 of the SDS. In addition, if there is only one relevant route of exposure and it is conclusively proven that no other routes cause the hazard, then the relevant route of exposure (oral, dermal or inhalation) must be specified in the hazard statement provided on the label and in section 2 of the SDS.

For the classification of substances and mixtures in STOT-RE — Category 1 and 2, data from standard animal (that is, rats or mice) studies, including 28-day, 90-day or lifetime (up to 2 years) studies that include hematological, clinico-chemical, and detailed macroscopic and microscopic examination, are considered. Data from repeat dose studies conducted in other animal species are also acceptable provided that these data provide relevant information on toxic effects on target organs/tissues.

Concentration value ranges

The dose or concentration at which effects are produced in animal studies needs to be considered to determine relevance for humans. Therefore, concentration value ranges have been established. These concentration value ranges are only applied when classifying based on animal data. The comparison to the specified concentration value ranges provides the necessary information to assign classification in the appropriate category.

The concentration value ranges from Tables 3.9.1 and 3.9.2 of the GHS, which are based on a standard 90-day study conducted in rats, are reproduced in Table 8.30 below. Extrapolation, similar to Haber's rule for inhalation, can be done for studies of longer or shorter duration. This extrapolation for a 28-day study is also shown in Table 8.30. Haber's rule for inhalation states that the effective dose is directly proportional to the exposure concentration and the duration of exposure.

The assessment must be done on a case-by-case basis; for example, for a 28-day study, the concentration value ranges must be increased by a factor of three (GHS, seventh revised edition, 2017, paragraph 3.9.2.9.5). Note that adjusting the concentration value ranges for very short study durations can lead to very high concentration value ranges which are not appropriate. For example, for a four-day exposure, a guidance value of 2250 mg/kg bw/day for classification in STOT-RE — Category 2 could potentially be produced. This is above the upper LD₅₀ value for Acute Toxicity — Oral — Category 4 of 2000 mg/kg bw. It does not make sense to have a guidance value for repeated dose toxicity that is above the guidance value for mortality after acute exposure.

To address this problem, a pragmatic approach is proposed. For studies with exposure durations shorter than nine days (that is, 10% of the 90 days to which the default general guidance value applies), the guidance value used should be no greater than 10 times the default guidance value. For example, the effects in an oral range-finding study of nine days or less should be compared with a guidance value of 1000 mg/kg bw/day for STOT-RE Category 2 (ECHA Guidance, 2017, p. 464).

There are no corresponding concentration value ranges for human data. Positive human data, regardless of probable dose, predominates over animal data. A substance with well-substantiated human data showing a specific target organ toxic effect after repeated exposure at very high doses must be classified in Category 1 even if there are animal data available which do not show toxicity at or below the established concentration value ranges.

Table 8.30 Concentration value ranges for repeat-dose exposures (adapted from: GHS, seventh revised edition, 2017, Tables 3.9.1 and 3.9.2)

		Concentration value ranges for:
		Category 1		Category 2
Route of exposure	Units	90 day study	28 day study	90 day study	28 day study
Oral (rat)	mg/kg bw/d	≤ 10	≤ 30	10 < C ≤ 100	30 < C ≤ 300
Dermal (rat or rabbit)	mg/kg bw/d	≤ 20	≤ 60	20 < C ≤ 200	60 < C ≤ 600
Inhalation (rat) gas	ppm V/6h/d	≤ 50	≤ 150	50 < C ≤ 250	150 < C ≤ 750
Inhalation (rat) vapour	mg/litre/6h/d	≤ 0.2	≤ 0.6	0.2 < C ≤ 1.0	0.6 < C ≤ 3.0
Inhalation (rat) dust/mist/fume	mg/litre/6h/d	≤ 0.02	≤ 0.06	0.02 < C ≤ 0.2	0.06 < C ≤ 0.6

bw = body weight; h = hour; d = day; C= dose/concentration

Test substances in repeat-dose animal studies are often administered in the feed or water, and the dosages are typically expressed in ppm or mg test substance/kg (feed) or mg (test substance)/litre (drinking water). Since the guidance values are expressed in mg/kg bw, a conversion from the reported value to mg/kg bw is necessary to determine whether classification criteria have been met. Occasionally, enough information is provided in the study to perform the conversion. Where the study provides insufficient detail to perform the conversion, Table 8.31 can be used to approximate the dose in mg/kg bw.

Table 8.31 Conversion to mg/kg bw (adapted from: Table V of Registry of Toxic Effects of Chemical Substances, U.S Department of Health and Human Services, National Institute for Occupational Safety and Health, July 1997)

Animal	Weight (g)	Food consumed (g/day)	Water consumed (ml/day)	Conversion- 1ppm in food in mg/kg bw/d	Conversion- 1ppm (mg/l) in water in mg/kg bw/d
Mouse	25	3	5	0.12	0.20
Rat (male)	250	15	25	0.06	0.10
Rat (female)	200	10	20	0.05	0.10
Rat (unspecified)	200	15	25	0.08	0.12
Rabbit	2000	60	330	0.03	0.16

Evaluating target organ toxicity

As described in the GHS (GHS, seventh revised edition, 2017, paragraph 3.9.2.7.3), the following are examples of relevant toxic effects in humans and/or animals considered to support classification:

1. Morbidity or death resulting from repeated or long-term exposure;
2. Significant functional changes in the central or peripheral nervous systems or other organ systems, including signs of central nervous system depression and effects on special senses (for example, sight, hearing and sense of smell);
3. Any consistent and significant adverse change in clinical biochemistry, hematology, or urinalysis parameters;
4. Significant organ damage noted at necropsy and/or subsequently seen or confirmed at microscopic examination;
5. Multi-focal or diffuse necrosis, fibrosis or granuloma formation in vital organs with regenerative capacity;
6. Morphological changes that are potentially reversible but provide clear evidence of marked organ dysfunction (for example, severe fatty change in the liver). Adaptive changes or changes in organ weights with no evidence of organ dysfunction do not support classification; and
7. Evidence of appreciable cell death (including cell degeneration and reduced cell number) in vital organs incapable of regeneration.

As described in the GHS (GHS, seventh revised edition, 2017, section 3.9.2.8), the following are examples of effects which may be seen in humans and/or animals that would not support classification:

1. Clinical observations or small changes in bodyweight gain, food consumption or water intake that may have some toxicological importance but that do not, by themselves, indicate "significant" toxicity;
2. Small changes in clinical biochemistry, hematology or urinalysis parameters and/or transient effects, when such changes or effects are of doubtful or of minimal toxicological importance;
3. Changes in organ weights with no evidence of organ dysfunction;
4. Adaptive responses that are not considered toxicologically relevant; and,
5. Substance-induced species-specific mechanisms of toxicity, that is, demonstrated with reasonable certainty to be not relevant for human health (subsection 2(9) of the HPR).

A substance that has not been tested for specific target organ toxicity may in certain instances, where appropriate, be classified in STOT–RE Category 1 or 2 on the basis of data from a validated structure activity relationship or extrapolation results from a structural analogue that has previously been classified, together with substantial support from consideration of other important factors such as formation of common significant metabolites (GHS, seventh revised edition, 2017, paragraph 3.9.2.10.3).

It is important to note that the primary target organ(s) must be identified for the evaluation of toxicity for STOT-RE; organs in which secondary effects were observed should not be included. For example, in the case of a hepatotoxicant, data on the secondary effects that it produces in the nervous or gastro-intestinal systems should not be included in the evaluation of classification.

Classification of Mixtures

Discussion of section 8.9.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for STOT-RE, which means that the procedures described in sections 8.9.3 to 8.9.5 of the HPR must be followed in the order in which these sections appear in the HPR. As specified in section 8.9.3 of the HPR, if there are test data for the mixture as a whole, these data may be used to classify the mixture. Section 8.9.4 of the HPR specifies which bridging principles may be applied to the STOT-RE hazard class. Finally, according to section 8.9.5 of the HPR, if there are no test data available for the mixture as a whole and bridging principles cannot be applied, then the classification of mixtures for STOT-RE is based on the evaluation of available test data for the individual ingredients of the mixture using concentration cut-off values for the ingredients classified in this hazard class.

Discussion of section 8.9.3 of the Hazardous Products Regulations

The first step in the tiered approach for the classification of mixtures uses data of the types referred to subparagraphs 2.1(a)(i) to (iv) of the HPR when available for the mixture as a whole. In this case, the classification procedure is the same as for substances, and is carried out according to section 8.9.1 of the HPR. The discussion sections of the guidance corresponding to section 8.9.1 of the HPR, as well as the discussion section relating to the classification of substances in general (Part 2), are relevant to the classification of mixtures if there is data available for the mixture as a whole. The data available on the mixture as a whole must be compared to the classification criteria within each category. If the data available meets the criteria in section 8.9.1 of the HPR, then the mixture must be classified in the category for which the criteria are met. Care should be exercised in evaluating data on mixtures, that the dose, duration, observation or analysis, do not render the results inconclusive (GHS, seventh revised edition, 2017, section 3.9.3.2).

Discussion of section 8.9.4 of the Hazardous Products Regulations

For this hazard class, the use of bridging principles is the second step in the tiered approach for the classification of mixtures.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there are sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

All of the bridging principles are applicable to the STOT-RE hazard class, namely: dilution, production batches, increase in concentration of hazardous ingredient, interpolation, substantially similar mixtures, and aerosols.

Discussion of section 8.9.5 of the Hazardous Products Regulations

Following application of sections 8.9.3 and 8.9.4 of the HPR, if a classification for the mixture as a whole cannot be determined, data available for the ingredients of the mixture are considered as the final step in the tiered approach for the classification of mixtures in this hazard class.

For mixtures, a concentration limit of ≥1% has been established when determining Category 1 or Category 2 classification for STOT-RE. If the mixture contains at least one ingredient which meets classification criteria for STOT-RE (Category 1 or 2) and is present in the mixture at a concentration ≥1%, then the mixture must be classified as STOT-RE — Category 1 or 2, as applicable.

As outlined below, for classification in Category 1 or 2 of STOT-RE, the additive approach is not applied. That is, the concentrations of individual ingredients that fall into STOT- RE — Category 1 or 2 are not to be added together, and the sum of the concentrations of those ingredients is not to be compared to the 1% concentration cut-off.

When classifying mixtures based on ingredient information, ingredients which demonstrate potentiation or synergistic interactions when combined need to be considered (subsection 2.4(1) of the HPR). Therefore, ingredients that are present in the mixture at < 1% and cause specific target organ toxicity when combined with potentiating ingredients must also be considered for classification.

Note: There are exceptions to the concentration limits established in section 8.9.5 of the HPR for classifying mixtures. Although concentration limits have been established in section 8.9.5 of the HPR, when an ingredient presents the hazard at a concentration which is below the concentration limit, and the mixture contains the ingredient at or above that concentration, the mixture must be classified in the category for which it meets the criteria. Refer to the discussion of section 2.5 of the HPR in Part 2 of the guidance for details.

Hazard Communication

The symbol, signal words, hazard statements, and precautionary statements for STOT-RE — Categories 1 and 2 are provided in Section 3 of Annex 3 of the GHS, seventh revised edition, 2017, pp. 362-363.

Note: As part of the hazard statement, the route(s) of exposure must be specified if it has been conclusively proven that no other routes of exposure cause the effect. In order to be able to specify the route of exposure, test data need to be available for all three relevant routes (oral, dermal and inhalation) and the data must clearly indicate that only one route leads to positive results.

For both substances and mixtures, the hazard statement must include all organs affected, if known. For example, if the mixture is classified on the basis of information available for its ingredients, the target organs affected by the ingredients must be identified. This information must be provided on the SDS and label.

Classification of STOT-RE for Substances Examples

Example 8.9.1: Evaluation/classification and allocation of hazard statements with respect to specific target organs and route of exposure (ECHA Guidance, 2017, paragraph 3.9.5.1.2)

Available data

1. Human data: no information available
2. Animal data:
   • LD₅₀ oral, rat 132 (males) and 176 (females) mg/kg: Acute Toxicity (Oral) — Category 3
   • LD₅₀ dermal 424 (males) and 983 (females) mg/kg: Acute Toxicity (Dermal) — Category 3
   • 4 hour LC₅₀ rat 0.69 mg/l: Acute Toxicity (Inhalation) — Category 2
   • Corrosive in animal experiments: Skin Corrosion — Category 1

STOT-RE oral: 28 day rat oral (gavage) study: doses 0; 1; 10; 50 mg/kg bw/d

• 1 mg/kg: No Observable Effect Level
• 10 mg/kg: Lowest Observable Effect Level
  • Increased liver weight but not statistically significant
  • Hepatic and splenic changes
  • Diminished red blood cell counts in females, no other changes in blood chemistry
  • Histopathology: in 2/10 males and 3/10 females swelling of parenchymal cells and increased polymorphism of the hepatocyte nuclei and the nuclear cells
• 50 mg/kg:
  • Mortality (3/8 males; 3/8 females); hepato- and nephrotoxicity responsible for mortality; no distinct hepato- and nephrotoxicity described for survivors
  • Hematology: decrease in red blood cell count ca. 20% and 21% in hemoglobin both in males and females; decrease in hematocrit 11%.

STOT-RE inhalation: 4 week inhalation study (vapour) rats: doses 0.5; 5; and 25 mg/m³/6h/d

• 0.5 mg/m³: No Observed Adverse Effect Concentration (NOAEC) for local effects in the respiratory tract
• 5 mg/m³ and 25 mg/m³: minimal–slight focal squamous metaplasia and inflammation in the larynx
• 25 mg/m³: NOAEC for systemic effects including hematology, clinical chemistry, histopathology and neuropathology examinations

Assessment

STOT-RE Oral: There is a steep dose response in the 28-day oral study. It can be concluded that at 10 mg/kg moderate but no "significant/ severe" toxicity could be expected. Severe effects are expected at 50 mg/kg.

STOT-RE Inhalation: There were no systemic effects observed up to the highest concentration tested. Since the substance is classified as corrosive to the skin, irritation of the respiratory tract by the vapour (a local effect) is expected and was observed at a minimal to slight degree at 5 and 25 mg/m³. It is assumed that the irritation would increase with higher concentrations. The corrosive/irritation potential is covered by the classification as Skin Corrosion — Category 1. Thus, no classification as STOT-RE with respect to the inhalation route would result.

Classification

STOT-RE — Category 2

Rationale

For a 28-day study, the GHS concentration value range for Category 2, adjusted according to Haber's rule, is 30-300 mg/kg/day. Significant effects were observed in the oral 28-day study for this substance at 50 mg/kg. These significant effects are not expected below 30 mg/kg/day, the adjusted concentration value limit for Category 1. Therefore, the substance must be classified in STOT-RE — Category 2 for the oral route, with the liver and kidneys as the target organs.

Classification for the inhalation route is not warranted, since at the highest concentration tested (25 mg/m³), only minimal to slight local effects were observed.

Labelling and SDS

The substance is classified as STOT-RE via the oral route, but not the inhalation route. In addition, specific toxicity has not been conclusively excluded for the dermal route (it can be expected due to high dermal absorption and classification as Acute Toxicity - Dermal — Category 3). Therefore, the hazard statement for STOT-RE must be applied without specifying a route. The hazard statement would be the following: "May cause damage to liver and kidneys through prolonged or repeated exposure".

Example 8.9.2: Evaluation/classification for mechanisms not relevant to humans (ECHA Guidance, 2017, paragraph 3.9.5.2.1)

Available data

1. Human data: no information available
2. Animal data: The only available data relate to a number of oral dose studies (up to 90 days duration) in rodents. In rats, the liver, thyroid and kidneys are the target organs for repeated dose toxicity. For the liver, increases in weight and changes in enzyme activity are seen in rats at exposure levels of 36 mg/kg/day or more. These effects are considered part of an adaptive response to an increase in metabolic demand. At higher exposure levels (around 360 mg/kg/day), single cell necrosis was observed in rats.

   Increased thyroid weight was observed in a 90-day study only at the highest exposure level tested, 625 mg/kg/day. Histopathologically, lesions such as hyperplasia have been observed down to the lowest exposure levels tested (for example, 0.4 mg/kg/day) with an exposure related increase in severity. However, the severity only ranged from "mild" to "moderate" even with an increase in exposure of three orders of magnitude. The thyroid changes (increased weight, and follicular hypertrophy and hyperplasia) are considered to occur as a result of repeated stimulation of this organ caused by the well-characterized negative feedback control effect arising from plasma T4 depletion. This repeated stimulation is related to an increase in the activity of hepatic UDPG-transferase. Humans, unlike rodents, possess a T4 binding protein that greatly reduces susceptibility to plasma T4 depletion and thyroid stimulation.

   No adverse renal effects were seen in male and female rats at 0.4 mg/kg/day in a 90-day study. Inner medullary tubular dilatation in the kidneys was seen at 4 mg/kg/day in females only. These lesions were slight, with changes increasing only marginally in severity and incidence at higher dose levels (up to 420 mg/kg/day for females). An exposure-related increase in the incidence and severity of a mixed population of interstitial inflammatory cells, tubular regeneration and minimal degenerative changes in the tubular epithelium was seen in treated males and females at 10 mg/kg/day or more. At 10 mg/kg/day, the severity of these changes was graded as 'trace', and even at the highest exposure level (625 mg/kg/day) the severity was only 'mild'. Mechanistic studies indicate deposition of β2μ globulin in proximal convoluted tubules, and this may be the primary mechanism for renal toxicity in male rats.

Classification

No classification for STOT-RE

Rationale

Effects on the liver justifying the classification (necrosis) are observed at a dose (360 mg/kg/day) that is above the concentration value ranges (10-100 mg/kg/day). Effects observed on the thyroid are specific for the rat and do not justify classification. Data regarding effects on the kidneys at doses around the concentration value ranges are not detailed enough to justify classification in any category.

Classification of STOT-RE for Mixtures Examples

Example 8.9.3: Data are available for the complete mixture (ECHA Guidance, 2017, paragraph 3.9.5.3.1)

Available data

A mixture has been tested in a valid 90-day oral study. At 90 mg/kg/day, severe liver damage (necrosis) was observed, and at 30 mg/kg/day, slight to moderate liver impairment was seen. The No Observed Adverse Effect Level was 9 mg/kg/day.

Classification

STOT-RE — Category 2

Rationale

Data is available from a valid, appropriate animal study for the complete mixture. Therefore, the criteria for substances are applied. Severe effects observed at 90 mg/kg/day in a 90-day study falls within the concentration value ranges for STOT-RE — Category 2 (10-100 mg/kg/day).

Example 8.9.4: Data are available for the ingredients of a mixture

Available data

No test data with respect to STOT-RE are available for the mixture as a whole. Bridging principles cannot be applied since no respective test data on a similar mixture are available. The classification of the mixture must then be based on the ingredients:

Table 8.32 Classification of STOT-RE for mixtures based on the ingredients.

Ingredient	Concentration (%w/w)	Classification
1	39	Not Classified
2	0.5	STOT-RE — Category 2
3	49.5	Not Classified
4	0.6	STOT-RE — Category 2

Classification

No classification for STOT-RE

Rationale

No ingredient is classified in Category 1. Therefore, the mixture cannot be classified in Category 1.

For STOT-RE, the additivity approach does not apply. No individual ingredient with a STOT-RE classification is present in the mixture at ≥ 1.0%.

There are no data indicating that either ingredient 2 or ingredient 4 demonstrate specific target organ effects after repeat exposure at the concentration at which they are present in the mixture. Therefore, subsection 2.5(1) of the HPR does not apply.

Notes:

If ingredient 2 and/or ingredient 4 is potentiated or demonstrates synergistic properties when combined with another ingredient in the mixture, a STOT-RE — Category 2 may result, in accordance with subsection 2.4(1) of the HPR.

Subpart 10 Aspiration Hazard

Discussion

Aspiration is the entry of liquid or solid materials through the mouth or nose into the trachea and lower respiratory system. Aspiration is initiated at the moment of inspiration, in the time required to take one breath, as the causative substance or mixture lodges in the throat (GHS, seventh revised edition, 2017, paragraph 3.10.1.3). Aspiration can also occur as the substance or mixture is vomited following ingestion (GHS, seventh revised edition, 2017, paragraph 3.10.1.4). The substance or mixture is swallowed, the swallowing leads to vomiting, and the resulting mixture of gastric juices and the substance or mixture enters the lungs (DGUV- Information, Fachbereich Holz und Metall, FB HM-049, Issue 11/2013).

Classification in the Category of the Class

Classification of Substances

Discussion of section 8.10.1 of the Hazardous Products Regulations

Classification is based on human evidence of aspiration toxicity or on the viscosity of a liquid substance (the viscosity of solids and substances suspended in the gas phase are not considered). Although the definition of aspiration toxicity includes the entry of solids into the lower respiratory system, classification according to item 1(b) of the criteria is intended to apply to liquid substances and mixtures only (GHS, seventh revised edition, 2017, paragraph 3.10.1.5.4).

Classification based on viscosity refers to kinematic viscosity. The conversion between dynamic and kinematic viscosity is:

Kinematic Viscosity (mm²/s) = Dynamic viscosity (mPa.s) / Density (g/cm³)

Viscosity depends on temperature. In the case of a liquid, viscosity generally becomes lower as the temperature increases. Therefore, if the kinematic viscosity for a liquid is 20.5 mm²/s at room temperature, the liquid must be classified in Aspiration Hazard — Category 1 based on the assumption that at 40°C (a higher temperature), the viscosity would be even lower. However, the temperature dependency of viscosity of liquids is generally not linear. Therefore, it is preferable to confirm the viscosity of the substance at 40°C (GHS Classification Guidance for the Japanese Government 2013 Revised Edition).

Classification of Aerosol/Mist Products

Aerosol and mist products need to be considered for classification unless it can be shown that the performance of the container would not allow the product to pool in the mouth. Aerosol and mist products are usually dispensed in containers such as self-pressurized containers, and trigger and pump sprayers. The key to classifying these products with regard to aspiration hazard is determining whether a pool of product may be formed in the mouth, which then may be aspirated. If the mist or aerosol from a pressurized container is in a finely divided form, a pool may not be formed. On the other hand, if a pressurized container dispenses product in a stream, a pool may be formed. Additionally, the mist produced by trigger and pump sprayers is coarse and therefore, a pool may be formed. Classification must also be considered when the pump mechanism can be removed and contents would be available to swallow (GHS, seventh revised edition, 2017, paragraph 3.10.1.5.5).

Animal Evidence

While a methodology for determining an aspiration hazard in animals has been developed, it has not been standardized (GHS, seventh revised edition, 2017, paragraph 3.10.1.5.2). Aspiration Hazard — Category 2, which exists under the GHS, has not been adopted in the HPR. Therefore, animal data are not considered for classification. If positive experimental evidence with animals is the only aspiration data available, then the substance is not classified.

Classification of Mixtures

Discussion of section 8.10.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for aspiration hazard, which means that the procedures described in sections 8.10.3 to 8.10.5 of the HPR must be followed in the order in which these sections appear in the HPR.

Discussion of section 8.10.3 of the Hazardous Products Regulations

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to in subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is the same as for substances, and is carried out according to section 8.10.1 of the HPR. The discussion of section 8.10.1 of the HPR, as well as the discussion section relating to the classification of substances in general (Part 2), are relevant to the classification of mixtures if there is data available for the mixture as a whole. If the available data meets the criteria in section 8.10.1 of the HPR, then the mixture must be classified in Aspiration Hazard — Category 1.

Discussion of section 8.10.4 of the Hazardous Products Regulations

For this hazard class, the use of bridging principles is the second step in the tiered approach for the classification of mixtures.

When there is no or insufficient data on the mixture as a whole, bridging principles can be applied if there is sufficient data available on similar tested mixtures and on the individual hazardous ingredients in the mixture to adequately assess the hazards of the mixture. The bridging principles are discussed in more detail in section 2.3 of Part 2 of this guidance.

All of the bridging principles, except for aerosols (subsection 2.3(8) of the HPR), are applicable to the Aspiration Hazard class, namely: dilution (note that the dilution principle does not apply if the concentration of aspiration toxicant(s) in the mixture is less than 10%), production batches, increase in concentration of hazardous ingredient, interpolation, and substantially similar mixtures.

Discussion of section 8.10.5 of the Hazardous Products Regulations

Following the application of sections 8.10.3 and 8.10.4 of the HPR, if a classification for the mixture as a whole cannot be determined, data available for the ingredients are considered as the final step in the tiered approach for the classification of mixtures in this hazard class.

This section considers "relevant ingredients" as ingredients that are present in concentrations of ≥ 1% unless, pursuant to subsection 2.5(1) of the HPR, there are data available that show that an ingredient present at < 1% poses an aspiration hazard at that concentration. The concentrations of all the relevant ingredients in Category 1 are added together (additivity approach) (see examples 1 and 2 of "Classification of Aspiration Hazard for Mixtures"). The sum of all the Aspiration Hazard — Category 1 ingredients must be ≥ 10.0% and the mixture must have a kinematic viscosity ≤ 20.5 mm²/s at 40°C for the mixture to be classified in this hazard class.

Special consideration has been given to mixtures which separate into two or more distinct layers. In these cases, the entire mixture is classified in Aspiration Hazard — Category 1 if in any distinct layer the sum of the concentration of ingredients in Category 1 is ≥ 10.0% and that layer has a kinematic viscosity ≤ 20.5 mm²/s, measured at 40°C.

Hazard Communication

The symbol, signal word, hazard statement, and precautionary statements for Aspiration Hazard — Category 1 are specified in Section 3 of Annex 3 of the GHS, seventh revised edition, p. 364. The GHS Aspiration Hazard — Category 2 has not been adopted in the HPR.

Classification of Aspiration Hazard for Substances Example

A review of the medical literature on chemical aspiration revealed that some hydrocarbons (petroleum distillates) and certain chlorinated hydrocarbons have been shown to pose an aspiration hazard in humans (GHS, seventh revised edition, 2017, paragraph 3.10.1.5.1).

Examples of substances included in Aspiration Hazard — Category 1 are certain aliphatic, acyclic and aromatic hydrocarbons, turpentine and pine oil.

Example 8.10.1:

Available data

Substance X is a hydrocarbon with a kinematic viscosity of 0.76 mm²/s at 25°C. Human case reports indicate "may cause chemical pneumonia if swallowed".

Classification

Aspiration Hazard — Category 1

Rationale

The kinematic viscosity test result meets the criterion in Item 1(b) of the table to section 8.10.1 of the HPR, as it can be assumed that at a higher temperature of 40°C, the viscosity would only be lower.

Available human data provides supporting evidence for classification.

Classification of Aspiration Hazard for Mixtures Examples

Example 8.10.2:

Available data

Human data for a mixture as a whole is not available and bridging principles cannot be applied. Therefore, classification is based on the ingredients in the mixture. The mixture is not a liquid hydrocarbon. The mixture has a kinematic viscosity of 17 mm²/s at 40°C.

Table 8.33 Classification of Aspiration Hazard for mixtures based on the concentration of the components.

Component	Concentration (w/w)%	Classification
A	1.5	Aspiration Hazard — Category 1
B	9.5	Aspiration Hazard — Category 1
C	8	Not Classified
D	15	Not Classified
E	66	Not Classified

Classification

Aspiration Hazard — Category 1

Rationale

Components C, D and E are not classified as aspiration hazards and therefore are not considered.

Components A and B are present at 1.5% and 9.5%, respectively, which are greater than the 1% cut-off concentration for a relevant ingredient.

Applying the additivity approach, the sum of Category 1 ingredients (Components A and B) is 11%. This value exceeds the concentration cut-off of 10%, as set out in paragraph 8.10.5 (a) of the HPR, and the kinematic viscosity of the mixture is ≤ 20.5 mm²/s at 40°C.

Example 8.10.3:

Available data

Human data for a mixture as a whole is not available and bridging principles cannot be applied. Therefore, classification is based on the ingredients in the mixture. The mixture is not a liquid hydrocarbon.

Table 8.34 Classification of Aspiration Hazard for mixtures based on the concentration of the components

Component	Concentration (w/w)%	Classification
A	0.9	Aspiration Hazard — Category 1
B	9.2	Aspiration Hazard — Category 1
C	8.9	Not Classified
D	15	Not Classified
E	66	Not Classified

Classification

Not classified

Rationale

Components C, D and E are not classified as aspiration hazards and therefore are not considered.

The concentration of Component A is less than 1%, and there is no evidence that it poses an aspiration hazard at or below its concentration in the mixture, therefore it is not considered in the summation.

Component B is present at 9.2%, which is greater than the 1% cut-off concentration for a relevant ingredient but is not ≥ 10% as set out in paragraph 8.10.5 (a) of the HPR.

Subpart 11 Biohazardous Infectious Materials

Biohazardous Infectious Materials (BIM) is not a health hazard class in the GHS, but it has been retained in the HPR to maintain the previous level of worker protection (see discussion of GHS Implementation in Canada and WHMIS in the Introduction).

Discussion of section 8.11 of the Hazardous Products Regulations

Biohazardous infectious materials are materials that contain one or more of the following and that cause or are likely to cause infection in humans or animals:

• Microorganisms (for example, bacteria, fungi, protozoa)
• Nucleic acid (for example, viruses, retroviruses) and
• Protein (for example, prions).

To classify a material as a biohazardous infectious material, the supplier must have information that the material contains a microorganism, nucleic acid, or protein that causes or is a probable cause of infection in humans or animals. If the supplier does not know or is uncertain as to whether a material contains such a microorganism, nucleic acid or protein, the material should not be classified in the BIM hazard class.

Distribution of diagnostic samples (such as blood, feces, sputum, urine, organs, or body tissue) for which the infectious status is unknown need not be classified in the BIM hazard class. However, if the infectious status is known, such as blood containing HIV, then the product is classified. Note, however that a number of exceptions apply specifically to products classified in this hazard class.

Classification in the Category of the Class

Classification of substances

Discussion of section 8.11.1 of the Hazardous Products Regulations

Other Applicable Definitions

The following definition of "Risk Group Classification" appears in subsection 1(1) of the HPR and is also discussed in Part 1 of this guidance.

Discussion – Risk Group Classification

Under the Human Pathogens and Toxins Act (HPTA), human pathogens are divided into four risk groups. Only three of these risk groups are relevant to classification under the HPR. Criteria for determining the risk group of a pathogen is based upon characteristics, such as:

• Pathogenicity – capacity to cause disease in humans/animals (hosts)
• Virulence – severity of disease in an infected host
• Infectious dose – amount of pathogen or number of organisms required to cause an infection in the host
• Mode of transmission – path travelled to infect person/animals (for example, direct contact, aerosolized droplets)
• Route of infection – route of entry into the host (for example, ingestion, inhalation)
• Host range – number of species that pathogen can infect
• Availability of effective preventive measures (for example, vaccines)
• Availability of effective treatment (for example, antibiotics, antivirals)
• Survival in the environment – stability of the pathogen outside the host.

The following terms are used in this Part, but their formal definitions appear in subsection 3(1) of the HPTA:

• Risk Group 2
• Risk Group 3
• Risk Group 4

Discussion – Risk Group 2

Risk Group 2 pathogens represent a moderate individual risk and a low community risk. They are listed in Schedule 2 of the HPTA and include:

• bacteria such as Bordetella pertussis (causes whooping cough) and Salmonella spp;
• viruses such as those that cause Hepatitis A, B, C, D and E;
• protozoa such as Plasmodium falciparum (causes malaria); and

Discussion – Risk Group 3

Risk Group 3 pathogens represent a high individual risk and a low community risk. They are listed in Schedule 3 of the HPTA and include:

• bacteria such as Mycobacterium tuberculosis (causes tuberculosis)
• viruses such as Human Immunodeficiency Virus (causes HIV/AIDS)
• fungi such as Blastomyces dermatitidis (causes blastomycosis – a lung infection) and
• prions such as Bovine Spongiform (causes mad cow disease).

Note: No protozoa are listed in Schedule 3 of the HPTA.

Discussion – Risk Group 4

Risk Group 4 pathogens represent a high individual risk and a high community risk. They are listed in Schedule 4 of the HPTA and only include viruses such as:

• Ebolavirus and Marburgvirus.

A substance is classified in BIM — Category 1 if it meets Risk Group 2, 3, or 4, as defined in subsection 3(1) of the HPTA. In practice, this means that a substance could meet the definition of Risk Group 2, 3 or 4 but may not be listed on either Schedule 2, 3 or 4 of the HPTA. If the material is not listed on any of these Schedules in the HPTA, it must be classified based on available data that shows that the material causes or has the probability of causing infection or toxicity and infection in humans or animals.

Classification of Mixtures

Discussion of section 8.11.2 of the Hazardous Products Regulations

Section 8.11.2 of the HPR indicates that there are no special rules, such as bridging principles, for classifying a mixture containing biohazardous infectious material as one of its ingredients. If a mixture contains at least one ingredient that meets the Biohazardous Infectious Material — Category 1 classification criteria, then the mixture must also be classified in Biohazardous Infectious Material — Category 1.

A concentration cut-off for BIM has not been established in the HPR, as these materials present a hazard even in miniscule amounts for which a definite number cannot be assigned.

Hazard Communication

The symbol and signal word required on the label for the BIM hazard class are found in Part 5 of Schedule 5 of the HPR. A hazard statement is also required, as indicated in Part 5 of Schedule 5 of the HPR; however, the specific wording of the hazard statement has not been prescribed. The supplier must provide a hazard statement that uses wording that describes the nature of the hazard. Specific precautionary statements have not been specified either, but appropriate precautionary statements relating to general, prevention, response, storage and disposal are required under subparagraph 3(1)(d)(ii) of the HPR.

For biohazardous infectious materials, a nine-heading appendix, which follows the format set out in Schedule 2 of the HPR - Information elements on safety data sheet - Biohazardous Infectious Materials, is required in addition to the 16-heading SDS detailed in Schedule 1 of the HPR – Information elements on a safety data sheet. This appendix must be provided immediately after the 16-heading SDS. Further information on this can be found in Part 4 of this guidance.

Exemptions

There are three exemptions, in subsections 5(2), 5(3) and 5(5) of the HPR, that pertain to labelling and SDS requirements for laboratory samples of hazardous products that are classified only in the BIM hazard class. These exemptions are discussed in Part 5 of this guidance.

Subpart 12 Health Hazards Not Otherwise Classified

Health Hazards Not Otherwise Classified (HHNOC) is not a GHS health hazard class.

Discussion of section 8.12 of the Hazardous Products Regulations

The HHNOC hazard class is intended to capture health hazards which are not already covered by any of the other health hazard classes discussed in Part 8 of the HPR.

This hazard class includes adverse health effects that

• could occur through acute or repeated exposure to the substance or mixture, and
• may or may not be lethal.

However, it does not include health hazards which fall into a GHS hazard category that has not been adopted in the HPR. For example, a substance or mixture that would fall under GHS Acute Toxicity — Category 5 or GHS Skin Irritation — Category 3 should not be classified in HHNOC.

Classification in the Category of the Class

Classification of Substances

Discussion of section 8.12.1 of the Hazardous Products Regulations

A substance is classified in HHNOC — Category 1 based on available human or animal data.

Classification of Mixtures

Discussion of section 8.12.2 of the Hazardous Products Regulations

There is a "tiered" approach for classifying mixtures for health hazards not otherwise classified, which means that the procedures described in sections 8.12.3 and 8.12.4 of the HPR must be followed in the order in which these sections appear in the HPR.

It is important to note that the bridging principles do not apply for this hazard class.

Discussion of section 8.12.3 of the Hazardous Products Regulations

Data available for mixture as a whole

As the first step in the tiered approach for the classification of mixtures, if data of the types referred to in subparagraphs 2.1(a)(i) to (iv) of the HPR are available for the mixture as a whole, the classification procedure is the same as for substances, and is carried out according to section 8.12.1 of the HPR. The discussion of section 8.12.1 of the HPR, as well as the discussion section relating to the classification of substances in general (Part 2), are relevant to the classification of mixtures if there is data available for the mixture as a whole. If the data available meets the criteria in section 8.12.3 of the HPR, then the mixture must be classified in HHNOC — Category 1.

Discussion of section 8.12.4 of the Hazardous Products Regulations

As a final step, when there is no data for the mixture as a whole, then classification of the mixture must be based on available information for the ingredients in the mixture.

For classification of mixtures using data on ingredient(s), a mixture is classified in HHNOC — Category 1, if it contains at least one ingredient at a concentration of greater than or equal to 1.0% that is classified in HHNOC — Category 1.

Note: There are exceptions to the concentration limits established in section 8.12.4 of the HPR for classifying mixtures. Although concentration limits have been established in 8.12.4 of the HPR, when an ingredient presents the hazard at a concentration which is below the concentration limit, and the mixture contains the ingredient at or above that concentration, the mixture must be classified in the category for which it meets the criteria. Refer to section 2.5 of the HPR and its discussion for details.

Hazard Communication

For substances and mixtures that meet the criteria to be classified in HHNOC — Category 1, the following information elements are required to be provided on the label, as specified in paragraph 3(1)(d) of the HPR:

• an appropriate hazard pictogram (that is, a hazard pictogram from Schedule 3 of the HPR that is applicable to the hazard)
• the signal word "Danger"
• hazard statement(s) that are appropriate to the hazard (that is, statements that describe the nature of the hazard) and
• appropriate precautionary statements.

As specified in item 2(b) of Schedule 1 of the HPR, these information elements must also be provided on the SDS.

Under item 2(a) of the SDS, the hazard classification (for example, HHNOC — Category 1) or a description of the hazard identified is required.

Classification of a Health Hazard Not Otherwise Classified for Mixtures Example

Example 8.12.1:

Available data

Data for the mixture as a whole is not available. Therefore, classification is based on data for the ingredients of the mixture, as follows:

Table 8.35 Classification of a health hazard not otherwise classified for mixtures based on the ingredients.

Ingredient	Concentration (w/w)%	Classification
A	0.6	HHNOC — Category 1
B	96.9	Not Classified
C	2	Not Classified
D	0.5	HHNOC — Category 1

Classification

Not Classified

Rationale

Ingredients B and C are not classified as HHNOC therefore are not considered when classifying the mixture.

Ingredients A and D are both classified in HHNOC — Category 1. Their combined concentration is 1.1% (> 1.0%). However, the additive approach does not apply to this hazard class. Neither ingredient A nor D is in the mixture above the established concentration cut-off of 1.0%. There are no data indicating that either ingredient A or D presents a health hazard not otherwise classified at the concentration at which they are present in the mixture. Therefore, subsection 2.5(1) of the HPR does not apply. Thus, the mixture is not classified in HHNOC — Category 1.

References for this section of the guide (Hazardous Products Regulations – Part 8 Health Hazard Classes)

• DGUV- Information, Fachbereich Holz und Metall, FB HM-049, Issue 11/2013
• ECHA Guidance on the Application of the CLP Criteria, Guidance to Regulation (EC) No 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, Version 5.0, July 2017
• GHS Classification Guidance for the Japanese Government 2013 Revised Edition
• Hazardous Products Act, R.S.C., 1985, c.H-3
• Hazardous Products Regulations, SOR/2015-17
• Human Pathogens and Toxins Act, S.C. 2009, c. 24
• OSHA Hazard Classification Guidance for Manufacturers, Importers, and Employers, 2016
• UN Globally Harmonised System of Classification and Labelling of Chemicals (GHS), seventh revised edition, 2017

Appendix A: Hazardous Materials Information Review Act: Mechanism to protect confidential business information

The Workplace Hazardous Materials Information System (WHMIS) requires that suppliers provide employers with the necessary information for the safe use of hazardous products in Canadian workplaces. This goal is accomplished through safety data sheets (SDS) and product labels, as legislated under the Hazardous Products Act (HPA) and its associated Hazardous Products Regulations (HPR). If a product is classified as a hazardous product and is not excluded from the scope of the HPA, but certain information required to be disclosed on the SDS or label is considered confidential business information (CBI) by a supplier or employer, a claim may be filed with Health Canada under the Hazardous Materials Information Review Act (HMIRA) and its Hazardous Materials Information Review Regulations (HMIRR) to exempt this information from disclosure. Both suppliers and employers may apply for an exemption from disclosure.

Legislative and Regulatory Framework

The circumstances in which exemptions from disclosing CBI are permitted along with the mechanism to file a claim for exemption are outlined in various Acts and Regulations.

The HPA requires certain information to be disclosed on an SDS and label subject to exemptions for CBI that may be claimed under the HMIRA.

The HMIRA prescribes the types of information that may be eligible for a claim for exemption, and defines the structure and function of the claims process. The HMIRA also requires Health Canada to determine the validity of claims for exemption, and permits Health Canada to assess the compliance of the SDS and label, or a portion of these, to which a claim relates.

The HMIRR includes the criteria that must be considered when the validity of a claim for exemption is assessed by Health Canada, and establishes the fees that apply to the filing or refiling of a claim.

Section 5.7 of the HPR prescribes the information that must be disclosed on the supplier SDS and label which are the subject of a claim for exemption under the HMIRA.

In their WHMIS legislation(s), the federal, provincial and territorial (FPT) occupational health and safety (OHS) agencies all designate Health Canada to oversee, review and issue decisions on claims for CBI disclosure exemption. Employers seeking to protect CBI therefore file their claim with Health Canada in accordance with their jurisdiction's regulations' reference to the HMIRA, and there is no requirement to notify any FPT OHS agencies. Disclosure requirements of the HPR are also mirrored by each of the FPT OHS legislations.

The Canada Labour Code (CLC)prescribes safety requirements for federally regulated workplaces, and it is directly referred to in the HMIRA. The rules are generally the same as those set out by all of the other FPT OHS agencies.

The Accord Act prescribes safety requirements for specific offshore regulated workplaces, and it is directly referred to in the HMIRA. The rules are generally the same as those set out by all of the other FPT OHS agencies.

Interpretation

Amendments were made to the HMIRA in the Budget Implementation Act 2019, No. 1. These amendments received Royal Assent on June 21, 2019 and came into force on March 18, 2020. The amendments give the Minister of Health the authority to review a claim for exemption and the accompanying SDS and label.

CBI is defined in subsection 10(1) of the HMIRA.

Hazardous Materials Information Review Act

This appendix addresses the following aspects of the CBI claim for exemption process:

1. Filing a Claim for Exemption
2. Review of Claim for Exemption
3. Review of Safety Data Sheet or Label
4. Exemption Periods
5. Suspension, Cancellation and Reinstatement of Exemption
6. Publication of Claims for Exemption Information
7. Confidentiality
8. Offence and Punishment

A: Filing a Claim for Exemption

If information required to be disclosed on the SDS or label is considered by a claimant to be CBI, a claim may be filed with Health Canada to exempt that information from the disclosure requirements of the HPA and the HPR. The information that may be exempted differs based on whether the claim is filed by a supplier or an employer. Note that only information required to be disclosed by the HPA, the HPR, the CLC or the Accord Act is eligible for an exemption from disclosure. Products which are not subject to the HPA, or ingredients which are not hazardous, cannot be part of a claim for exemption under the HMIRA.

Supplier Claims

Subsection 11(1) of the HMIRA specifies the information that can be exempted from disclosure for suppliers. A supplier may seek an exemption from disclosing information that has economic value because it is confidential. The intent of the supplier claim is to allow suppliers to protect the exact formulation or other information that, if disclosed, would disadvantage the supplier. The CBI must not be publicly available and reasonable measures must have been taken to ensure that the CBI remains not publicly available. In addition, the CBI must have actual or potential economic value and its disclosure would result in a material financial loss to the person or material financial gain to their competitors. The information eligible for exemption is called the "subject" of the claim. The subjects are separated into two broad categories: those to exempt information linked to products that are a material or a substance, and those to exempt elements of products that are a mixture.

For hazardous products that are a material or a substance, a supplier may seek an exemption from disclosing the identity of the substance or material (chemical name, Chemical Abstracts Service (CAS) registry number, or any other unique identifier of the material or substance), and the name of any impurities, stabilizing solvents or stabilizing additives that are present with the material or substance and that are required to be disclosed on an SDS.

For hazardous products that are a mixture, a supplier may seek an exemption from disclosing the identity of any of the ingredients that are required to be on the SDS (chemical name, CAS registry number, or any other unique identifier) and/or the concentrations of one or more ingredients that are required to be on the SDS. The actual concentration or actual concentration range can be protected through the use of a prescribed concentration range under section 4.4.1 or 4.5 of the HPR, or a range that falls entirely within any one of those ranges. However, there are circumstances which would require a claim for exemption to be filed in order to protect the actual concentration or actual concentration range. For further information see the discussions on sections 4.4.1 and 4.5 of the HPR in this guidance.

If a supplier has filed a claim to protect the identity of a material or substance, or of an ingredient in a mixture, the supplier is required to disclose a generic chemical name (GCN) on the SDS, instead of disclosing the chemical name and CAS registry number of the ingredient (or any impurities, stabilizing solvents or additives in the case of a material or substance), as required by subsection 5.7(5) of the HPR. The GCN chosen should convey as much of the chemical characteristics of the material, substance, ingredient, impurity, stabilizing solvent or additive as possible, without disclosing its identity. Additional guidance on the creation of a suitable GCN can be found in Appendix B.

Where a supplier has filed a claim for an exemption from disclosing the actual concentration or actual concentration range of one or more ingredients, suppliers are encouraged to provide a replacement concentration range on the SDS, provided the actual concentration or actual concentration range is contained within the replacement range.

A supplier may also file a claim for an exemption from disclosing the name of a toxicological study that would identify a CBI hazardous ingredient. In accordance with section 6.1 of the HPR, a supplier "must disclose, as soon as feasible, the source of information for any toxicological data used in the preparation of a safety data sheet on the request of an inspector, any person or government to which the hazardous product is sold or any user of a hazardous product". However, section 6.1 of the HPR specifies that it is subject to the application of the HMIRA, such that the requested information could be withheld if a claim had been made under the HMIRA to exempt that information from disclosure.

Example:

Table 9.1: Product composition

Ingredient	CAS Number	% (w/w)
Methanol	67-56-1	20%
Trichloroisocyanuric Acid	87-90-1	0.1%
Water	7732-18-5	79.9%

Table 9.2: SDS Section 3- Composition/Information on ingredients

Ingredient	CAS Number	% (w/w)
Alcohol Table 9.2 Footnote *	Proprietary Table 9.2 Footnote *	20%
Trichloroisocyanuric Acid	87-90-1	0.1%
*HMIRA registry number: 3333 – Filing Date January 1, 2021

Note that water does not require disclosure on the SDS as it does not meet any health hazard classification criteria.

Employer Claims

Subsection 11(2) of the HMIRA specifies the information that can be exempted from disclosure for employers. Employer claims are very similar to supplier claims. The main difference is that the intent of the employer claim is to allow employers to keep confidential information that must appear on an SDS or a label where that SDS or label is intended to be used, stored or handled in their workplace. If the employer were to sell the same product to another person, rather than just using it in their workplace, they would become a "supplier" as defined in the HPA, and a separate supplier claim would need to be filed with Health Canada under the HMIRA in order to exempt the CBI from disclosure under the HPA. In the case of an employer claim, the claimant seeks to protect specific information on the product that, if disclosed, would disadvantage the employer. The CBI must not be publicly available and reasonable measures must have been taken to ensure that the CBI remains not publicly available. In addition, the CBI must have actual or potential economic value and its disclosure would result in a material financial loss to the person or material financial gain to their competitors. With that intent, the HMIRA allows employers to claim for the same exemptions as suppliers. In addition, employers may also file a claim to protect the identity of the hazardous product or supplier, as follows:

• The product identifier of the hazardous product (chemical name, common name, generic name, trade-name or brand name)
• Information about the hazardous product, other than the product identifier, that constitutes a means of identification
• Information that could be used to identify the supplier of the hazardous product

In these cases, the employer must replace the claimed information with the following:

• For claims regarding the product identifier, a code name or code number in lieu of the product identifier, as well as the information required under subsection 5.7(3) and 5.7(4) of the HPR, or if that information is not available, the information required to be provided by the laws of the province (subsection 5.7(9) of the HPR);
• For claims regarding the identity of the supplier, the information required under subsection 5.7(3) and 5.7(4) of the HPR, or if that information is not available, the information required to be provided by the laws of the province (subsection 5.7(10) of the HPR);
• For claims under subsection 11(2) of the HMIRA, the information required under subsection 5.7(3) and 5.7(4) of the HPR or if that information is not available, an emergency telephone number of the employer that will enable a health professional to obtain certain information (subsection 5.7(11) of the HPR).

Example:

Original Product

Table 9.3: Example of SDS Section 1 of the original product

Super Sanitizer
Use: Sanitization
Supplier: Brand Name Company 100 James Bay Street, Mytown, Ont 123-456-7890
Emergency Phone Number: 1-800-XXX-XXXX

Table 9.4: Example of SDS Section 3 of the original product

Ingredient	CAS Number	% (w/w)
Methanol	67-56-1	20%
Trichloroisocyanuric Acid	87-90-1	0.1%

Employer Redacted Product

Table 9.5: Example of SDS Section 1 of the redacted product

Employer Sanitizing product Table 9.5 Footnote *
Use: Sanitization
Supplier: Employer's Company Table 9.5 Footnote * 13 Fedstreet Yourtown, Ont 123-000-1234
Emergency Phone Number: 1-800-YYY-YYYY
*HMIRA RN: 4444 – Filing Date January 1, 2022

Table 9.6: Example of SDS Section 3 of the redacted product

Ingredient	CAS Number	% (w/w)
Methanol	67-56-1	20%
Trichloroisocyanuric Acid	87-90-1	0.1%

Application for a Claim for Exemption

The information required for a claim for exemption includes:

• Claimant contact information
• Subject matter of the claim for exemption and supporting information, as applicable
• Product information, including a description of the full composition
• SDS and/or label for the hazardous product in both official languages, and
• Payment information (Refer to the fee structure and payment information on the WHMIS webpage for more information)

Subsection 8(1) of the HMIRR further details the required content of a claim.

Health Canada has developed a form to be completed by claimants or a third party agent that captures all information required by the HMIRA and HMIRR to file a claim. The Claim for Exemption under the Hazardous Materials Information Review Act - Application Form can be found on online or by e-mailing whmis.claim-demande.simdut@hc-sc.gc.ca. For guidance on completing the form, see the Guide for using the claim for exemption online application form for workplace hazardous products.

Full Composition

In accordance with subparagraph 8(1)(g)(iv) of the HMIRR, a claim for exemption must contain the chemical name and, if any, the CAS registry number and any other unique identifier of all materials, substances, ingredients, impurities, stabilizing additives and stabilizing solvents in the hazardous product and their actual concentrations or actual concentration ranges. As such, the full composition of the product is required. Information may be requested from the claimant, in accordance with subsection 16(2) of the HMIRA, to clarify the composition of the product. For further information, including examples of additional information that may be requested, see the discussion on subsection 16(2) of the HMIRA in this guidance.

SDS and Label

The wording in subsection 11(4) of the HMIRA is that the "claim for exemption shall be accompanied by the safety data sheet or label to which the claim relates". Since a supplier can only file a CBI claim for information required to appear on the SDS, a supplier claim must be accompanied by the SDS. In contrast, an employer can file a CBI claim for information required to appear on the label and/or the SDS, so one or both documents must be submitted with the claim depending on if the claim relates to the label and/or the SDS. The SDS (and label) must not be missing any required information. The product identifier, composition information, and any GCNs that must appear on the SDS must also match the information submitted in the application. Information claimed as CBI must not appear on the SDS or label.

In addition, claimants can provide any and all relevant toxicological studies that were used to support the development of the SDS and label content. All proprietary (that is, not publicly available) data that the claimant wishes to have Health Canada consider is requested to be submitted at the time of filing of the application.

Please note that claimants who submitted SDSs and labels based on the former HPR prior to the end of the transition period may be required, at Health Canada's request, to provide a revised SDS and/or label based on the amended HPR following the end of the transition period.

HMIRA Registry Number

Once a complete application package, including fees, is received by Health Canada, an HMIRA registry number is assigned, and a determination of claim validity is issued. If an application does not have all the necessary information, the missing information may result in delays. Once the HMIRA registry number is issued, the claimant is granted an interim exemption from disclosing the CBI until all judicial reviews and appeals are exhausted, subject to any suspension or cancellations. If a claim, or a portion of a claim, is valid after all judicial reviews and appeals are exhausted, then the claimant is granted a three-year exemption period, subject to any suspension or cancellations.

Section 5.7 of the HPR states that information that is exempt from disclosure under the HMIRA must be replaced with the following information:

• Where an HMIRA registry number has been assigned, the supplier is required to provide on the SDS and label a statement that a claim was filed, the date that the claim was filed and the HMIRA registry number, until the time specified under subsection 5.7(3) of the HPR (see subsection 5.7(3) of the HPR). For example, "HMIRA claim for exemption (RN XXXX) filed on dd/mm/yyyy".
• Where a claim, or portion of a claim, is valid after the period specified in subsection 5.7(4) of the HPR, the supplier is required to provide on the safety data sheet and label a statement that an exemption has been granted, the date of the determination granting the exemption and the HMIRA registry number (see subsection 5.7(4) of the HPR). For example, "HMIRA claim for exemption (RN XXXX) granted on dd/mm/yyyy".

Change in Ownership

An HMIRA registry number is issued to a given hazardous product. A change in the ownership of the hazardous product means a change in the claimant. Health Canada requires written notification of the change in ownership. Please contact Health Canada for further guidance on providing written notification. Upon receipt of such notification, the existing exemption (product with HMIRA registry number) is transferred to the new owner.

Change in Product Identifier

Note that if a product identifier is changed, either by reason of change in ownership or for any other reason, a new claim for exemption must be filed.

B: Review of Claim for Exemption

Claim Validity

Health Canada will review each submitted claim, or a portion thereof, and determine its validity.

The requirements to determine claim validity are set out in section 3 of the HMIRR. Health Canada must consider the following criteria:

• whether the information is not publicly available
• whether the claimant has taken measures that are reasonable in the circumstances to ensure that the information remains not publicly available
• whether the information has actual or potential economic value to the claimant or to the claimant's competitors because it is not publicly available and its disclosure would result in a material financial loss to the claimant or a material financial gain to the claimant's competitors

To determine if a claim, or a portion thereof, is valid, Health Canada must also consider whether the money expended and the other business resources employed by the claimant to develop the information are substantial in the circumstances. For example, the money and business resources expended to develop the ingredient identity or concentration in the product. However, this information cannot be used for the purpose of determining that such a claim for exemption is not valid. That is, an exemption would not be denied on the grounds that insufficient expenses were incurred to develop the information.

The outcome of this portion of the claim review is either a finding that the claim is valid, partially valid, or invalid. Additional information may be required.

If additional information is required to determine the validity of the claim, or a portion thereof, Health Canada may, pursuant to subsection 12(2) of the HMIRA, request additional information that it considers necessary from the claimant. Claimants are required to provide the requested information in the manner and within the period specified by Health Canada, in accordance with subsection 12(2) of the HMIRA.

Once Health Canada has determined the validity of the claim, or a portion thereof, the claimant will be notified in writing of the determination and the reasons for it.

For valid and partially valid claims, the "decision granted date", which is the date of the determination granting the exemption, must be disclosed on the SDS and label, where applicable (see subsection 5.7(4) of the HPR). For an employer claim, other information must be included if the "decision granted date" is not available. For claims relating to the product identifier or supplier identity, the information required to be provided under the laws of the province must be provided (see subsections 5.7(9) and 5.7(10) of the HPR). For claims for exemption under subsection 11(2) of the HMIRA, an emergency telephone number of the employer that will enable a health professional to obtain certain information must be provided (see subsection 5.7(11) of the HPR).

Example:

Table 9.7: Example of SDS Section 3

Ingredient	CAS Number	% (w/w)
Alcohol Table 9.7 Footnote *	Proprietary Table 9.7 Footnote *	20%
Trichloroisocyanuric Acid	87-90-1	0.1%
* HMIRA RN: 3333 – Decision Granted Date April 1, 2021

If a claim does not meet the criteria laid out in section 3 of the HMIRR, it will be determined to be invalid by Health Canada. In cases where the exemption is sought for more than one ingredient or subject, such as identity and concentration, the claim will be determined to be partially valid if some of the ingredients or concentrations meet the criteria, but others do not.

In accordance with subsection 14(1) of the HMIRA, if Health Canada determines that a claim for exemption is partially valid or invalid, Health Canada may order the claimant to:

• comply with the HPA, CLC or Accord Act in respect of the portion of the claim that was not valid, or
• to remove information specified in the order from the SDS or label.

The claimant is required to comply with the order in the manner and within the time specified in the order. Failure to comply with the order within the specified timeframe may result in the suspension or cancellation of the exemption. For further information, see the discussion on Suspension, Cancellation and Reinstatement of Claims for Exemption.

An example of an invalid claim may include:

• Evidence that information that is the subject of a claim is available in a public domain. In this case, Health Canada may order the disclosure of the information that is the subject of the invalid claim and/or the removal of the HMIRA registry number, as applicable. Health Canada may request evidence that demonstrates that the order has been satisfied, such as an updated SDS and/or label, and upon its receipt, may confirm that the claimant has been deemed compliant.

C: Review of Safety Data Sheet or Label

SDS and Label Compliance

In accordance with section 15 of the HMIRA, it does not constitute a failure to comply with the provisions of the HPA, provisions of the CLC, or provisions of the Accord Act if the information that is not provided on an SDS or label accompanying a claim for exemption is the subject of the claim, for the purpose of:

• Any review of the SDS or label by Health Canada to determine compliance under subsection 16(1) of the HMIRA
• The issuing of an order under subsection 18(1) of the HMIRA
• The suspension or cancellation of a claim under paragraph 21(b) of the HMIRA.

Health Canada may review the compliance of the SDS or label accompanying any claim, or any portion of the SDS or label.

The review of the SDS or label, or a portion of the SDS or label, is based on the scientific review of physical and toxicological data and is done in accordance with the requirements of the HPA, HPR, CLC or Accord Act. Refer to sections in this guidance that discuss the HPA and HPR for more information on these requirements.

If the claimant has proprietary data (that is, not publicly available) that they want Health Canada to consider, it is requested that claimants submit these studies at the time of filing (that is, with the application package).

If additional information is required to determine the compliance of the SDS or label, or any portion of the SDS or label, with the HPA, HPR, CLC or Accord Act, Health Canada may request additional information from the claimant that it considers necessary to make that determination. Pursuant to subsection 16(2) of the HMIRA, claimants are required to provide the additional information in the manner and within the period specified in the request made by Health Canada. If the additional information requested is not available to the claimant, Health Canada may proceed with its evaluation but would do so by assuming the worst case scenario.

The following are examples of additional information that could be requested from the claimant:

Generic CAS numbers:

A generic CAS number refers to a group of related but different chemicals with different toxicological profiles. The hazard properties may vary with the form of the chemical, the molecular weight, or the number of repeating units.

For example, silica has a generic CAS number (7631-86-9) that refers to all types of silica found. There are also eleven specific CAS numbers for silica, which may be mineral, biogenic or synthetic in origin. Silica can also be crystalline or amorphous in form.

When a generic CAS is provided in the product composition, Health Canada may contact the claimant to identify if there is a more specific identity for that ingredient than what is represented by the generic CAS number.

Complex mixtures:

A "complex mixture" is defined in section 5.6 of the HPR as a mixture that has a commonly known generic name and that is:

1. naturally occurring;
2. a fraction of a naturally occurring mixture that results from a separation process; or
3. a modification of a naturally occurring mixture or a modification of a fraction of a naturally occurring mixture that results from a chemical modification process.

For example, commercial xylene is a mixture of three isomers, the ratio depending on the source, with m-xylene predominating. It also contains ethylbenzene (6-20%), and smaller amounts of toluene, trimethylbenzene, phenol, thiophene, pyridine and non-aromatic hydrocarbons.

When a complex mixture appears to be part of the product based on the composition information provided by the claimant, Health Canada may contact the claimant to establish if the components of the mixture were added separately or as a complex mixture. If the components were not added separately, Health Canada may only assess the complex mixture, as opposed to individual components.

Contact information of a Canadian regulated party

In the event that a claimant is located outside of Canada, the contact information of a Canadian regulated party may be requested for follow-up purposes

If, based on its review, Health Canada is likely to determine that the SDS and/or label does not comply with provisions of the HPA, the HPR, the CLC, and/or the Accord Act, a consultation period is initiated with the claimant by sharing an "SDS and label compliance review consultation document". This document communicates points that form the basis for a likely finding of SDS and/or label non-compliance and invites the claimant to provide comments. The due date for feedback regarding information communicated in the consultation document must be adhered to by the claimant in order for any additional information to be taken into consideration prior to the issuance of a final decision on SDS and/or label compliance. Where required, an extension may be granted by Health Canada if requested prior to the communicated deadline and if appropriate justification is provided.

A final decision on the compliance of the SDS and, if applicable, the label, with the provisions of the HPA, the HPR, the CLC and/or the Accord Act, will be communicated to the claimant in writing and will include reasons for the determination.

In the case where an SDS and/or label non-compliance with the HPA, the HPR, the CLC and/or the Accord Act is identified, the claimant is normally given an opportunity to first comply voluntarily. Where the risk to worker health and safety warrants it, Health Canada may pursue other options, in lieu of voluntary compliance, to seek to obtain necessary corrective measures more rapidly.

When a claimant does not voluntarily make the corrections required to the SDS and/or label in the time specified, Health Canada may issue an order for the claimant to do so. To comply with the order, the claimant is required to submit an SDS and, if applicable, label amended in accordance with the order, and the SDS and/or label must be submitted within the time specified in the order.

Until the order is complied with, suppliers are prohibited from importing or selling a hazardous product intended for use, handling or storage in Canada, or in the case of an employer's claim, the use of the product in the workplace is prohibited, if the product's SDS and/or label does not comply with the HPR. This is until such time as the SDS and/or label has been amended to be in compliance with the HPA and its regulations or, if applicable, the provisions of the CLC or the provisions of the Accord Act.

Contravening or failing to comply with any provision of the HMIRA and its related regulations or any order made under the HMIRA may result in further compliance and enforcement actions.

D: Exemption Periods

After a claim for exemption is assigned an HMIRA registry number, the claimant is temporarily exempted from disclosing the subject of the claim on the SDS or label, in accordance with subsection 19(1) of the HMIRA. If the claim for exemption is found to be valid, the calculation for the exemption period is as follows:

• Where a decision on the claim validity was made prior to March 18, 2020 and the decision was published in the Canada Gazette prior to that date, the expiry date of a valid claim is 3 years from the expiry of the 45-day appeal period after the decision was published in the Canada Gazette.
• Where a decision on the claim validity was issued prior to March 18, 2020 but was not published in the Canada Gazette prior to that date, the expiry date of a valid claim is 3 years from the day after all judicial reviews and appeals are exhausted.
• Where a decision on the claim validity was made on or after March 18, 2020, the expiry date of a valid claim is 3 years from the day after all judicial reviews and appeals are exhausted.

Should a claimant choose not to re-apply upon expiry of the exemption period, the registry number associated with the product claim is no longer valid and cannot be used or referenced. There are two options for expired exemptions:

• Disclose the CBI and replace any GCNs with true chemical names and CAS registry numbers (if applicable) and concentrations where applicable, and remove the HMIRA registry number and the date of decision from the SDS and, where applicable, from labels; or
• Withdraw the product from the Canadian market or, in the case of an employer claim, from the workplace.

E: Suspension, Cancellation and Reinstatement of Exemption

Under the circumstances described in sections 21 and 22 of the HMIRA, Health Canada may suspend or cancel an exemption.

After a claim for exemption filed under the HMIRA is registered, and until all judicial reviews and appeals are exhausted, Health Canada may suspend or cancel the exemption in the following circumstances:

• the claim, or any portion of it, is not valid
• the SDS or label does not comply with the HPA, CLC or the Accord Act
• the claimant does not comply with a request for additional information under subsection 12(2) or 16(2) of the HMIRA
• the claimant contravenes the HPA, CLC or the Accord Act or
• the claimant contravenes an order under section 14 or 18 of the HMIRA

If the claim for exemption was determined to be valid and all judicial reviews and appeals have been exhausted, Health Canada may suspend or cancel the exemption in the following circumstances:

• Health Canada has reasonable grounds to believe that the claim for exemption included false or misleading information
• the claimant contravenes the HPA, CLC or the Accord Act; or
• the claimant contravenes an order under section 14 or 18 of the HMIRA

Health Canada will notify the claimant in writing if an exemption has been suspended or cancelled and will provide the reasons for the suspension or cancellation. In accordance with subsection 23(1) of the HMIRA, the suspension or cancellation takes effect on the day of the written notification from Health Canada. The claimant has 10 days after they are notified to provide Health Canada with reasons why the claimant believes the suspension or cancellation is unfounded.

In accordance with sections 24 and 25 of the HMIRA, if the claimant demonstrates that the suspension or cancellation was unfounded, Health Canada will reinstate the exemption. In addition, if the reasons for the suspension no longer exist, Health Canada will reinstate a suspended exemption.

F: Publication of Claims for Exemption Information

Once a registry number has been issued for a claim for exemption filed under the HMIRA, information regarding the claim will be published on Canada.ca, such as the claimant name, product identifier, registry number and date of filing. When a decision is issued in respect of the claim, the website will be updated to reflect the results of the decision. In addition, if an order is issued, this information will also be published on the website.

The following information will be published about each registered claim for exemption filed under the HMIRA:

• Case number
• Claimant name
• Claim validity status
• Claim validity decision date
• Date of claim status
• Date of filing
• Date of the order (if issued)
• Date resolved
• Decision date
• Expiry date of exemption period
• List of non-compliances / corrective measures
• Non-compliances identified on SDS or label
• Product ID
• Registry number
• SDS and/or label compliance review decision date (as applicable)
• Status of the claim / claim status
• Status of the order
• Type of claim (whether "Original" or "Refile")
• Validity of the claim

G: Confidentiality

Sections 27 to 29 of the HMIRA provide that the Minister may disclose CBI obtained by Health Canada under the HMIRA without the consent of the claimant under certain circumstances.

Section 27 of the HMIRA allows the Minister to disclose CBI obtained in a claim for exemption by a supplier or employer under the HMIRA if the disclosure is necessary to address serious and imminent danger to human health, safety or the environment. The HMIRA does not provide a definition of "serious and imminent danger to human health or safety or to the environment". The decision to disclose CBI to address serious and imminent danger must be evaluated on a case-by-case basis, and may be informed by a number of factors including:

• A recommendation based on a scientific assessment done by Health Canada – for example, assessment of a filed claim for exemption, analysis of available studies and any additional information received.
• A recommendation based on information about a product or ingredient – for example, from a manufacturer, patient or healthcare institution, international regulatory agency, reports published in medical/scientific literature, or from an inspection performed by Health Canada or another regulator.
• The seriousness of the adverse health consequence or potential adverse health consequence – a serious adverse health consequence includes any untoward occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, or is a congenital anomaly/birth defect.
• The vulnerability of the patient population and/or sub-population that are exposed to the particular hazardous product. Vulnerable populations may include, but are not limited to: children, the elderly, pregnant and lactating women, and immunocompromised patients.
• The extent of the population's exposure to the hazardous product and the potential public health impact of the exposure.

Subsection 28(1) of the HMIRA allows the Minister to disclose CBI obtained in a claim for exemption by a supplier or employer under the HMIRA to a government or a person from whom they seek advice if the purpose is to protect human health or safety or the environment from a significant risk. The government or person must also agree in writing to maintain confidentiality of the information they received and to use it only for the purposes for which the CBI was initially disclosed. In accordance with subsection 28(2) of the HMIRA, the Minister must notify the person to whose business or affairs the information relates before disclosing the information under these circumstances.

Section 29 of the HMIRA allows the Minister to disclose CBI obtained in a claim for exemption by a supplier or employer under the HMIRA to any physician or prescribed medical professional who requests that information for the purpose of making a medical diagnosis of, or rendering medical treatment to, a person in an emergency.

Note that the Minister is not required to receive consent prior to disclosing information for the purposes outlined in sections 27 and 29 of the HMIRA, but must notify the person to whose business or affairs the information relates no later than the next business day after the day on which the information was disclosed in accordance with subsection 30(1) of the HMIRA.

In accordance with section 31 of the HMIRA, any person or government to whom CBI was disclosed to for any reason permitted by the HMIRA (section 27, 28 or 29) must also keep the information confidential. They must not knowingly disclose the CBI to other parties unless it is for the purpose for which the CBI was initially disclosed.

H: Offence and Punishment

The potential consequences of contravening or failing to comply with any provision of the HMIRA and its related regulations or any order made under that Act are provided in section 49 of the HMIRA.

A person who contravenes or fails to comply with any provision of the HMIRA and its regulations or any order made under that Act may be imprisoned for up to six months and/or liable to a fine of up to one hundred thousand dollars in the case of a summary conviction. In the event of proceedings by way of indictment, imprisonment could increase to up to two years and/or a fine of up to one million dollars.

Furthermore, failure to comply with the provisions of the HPA or its regulations or any order made under that Act is an offence under that Act, and the extent of punishment is provided in section 28 of the HPA. A person who contravenes a provision of the HPA, its regulations, or an order under that Act may, in the case of a summary conviction, be imprisoned for not more than six months and/or liable to a fine of up to two hundred and fifty thousand dollars for a first offense and may be imprisoned not more than eighteen months and/or liable to a fine of up to five hundred thousand dollars for a subsequent offence. In the event of proceedings by way of conviction on indictment, a person may be imprisoned for not more than two years and/or liable to a fine of not more than five million dollars.

References for this section of the guide (HMIRA: Mechanism to protect confidential business information)

• 29 CFR 1910.1200, Hazard Communication
• Hazardous Materials Information Review Act, R.S.C. 1985, c. 24 (3rd Supp.), Part III
• Hazardous Materials Information Review Regulations, SOR/88-456
• Hazardous Products Act, R.S.C., 1985, c. H-3
• Hazardous Products Regulations, SOR/2015

Appendix B: Developing a generic chemical name

Introduction

A supplier or employer may seek an exemption from the requirement to disclose the name of a confidential ingredient on a safety data sheet (SDS) by filing a claim for exemption with Health Canada under the Hazardous Materials Information Review Act (HMIRA). In such cases, the claimant must disclose a generic chemical name (GCN) on the SDS in lieu of the chemical name, under subsection 5.7 (5) of the Hazardous Products Regulations (HPR). The GCN also must be submitted to Health Canada as part of the claim for exemption filed under the HMIRA.

In addition, a GCN may be used on the label for a laboratory sample exempted by subsection 5(5) or 5(6) of the HPR without filing a claim under the HMIRA. Please refer to Part 5 of this guidance for more information. A GCN may also be used for a non-hazardous ingredient (not required for disclosure on an SDS) so long as the SDS makes clear that the ingredient is not hazardous under the Hazardous Products Act (HPA) or HPR.

Guidance for the derivation of a GCN

A GCN is a chemical name that is less specific than the true chemical name but no more general than is necessary to protect the confidential business information (CBI). A GCN should be unique and unambiguous, and a claimant should be able to explain or justify to Health Canada, upon request, the extent of the name modification that is necessary to protect the CBI. The GCN, like all other information in the SDS, is subject to the prohibition in section 14.2 of the HPA, and as such, must not convey false or misleading information about the nature of the chemical identity.

Strategy for developing a GCN

Several sources for a chemical name can be used as the starting point to develop a GCN. Most chemical names are derived using systematic nomenclature such as the one developed by the International Union of Pure and Applied Chemistry (IUPAC) or from the Chemical Abstracts Service (CAS). Several sources are available to obtain systematic chemical names, such as ChemID through the National Library of Health (1), the CRC Handbook of Chemistry and Physics (2) and the Merck Index (3).

One method of developing a GCN is to use the approach set out by the Masked Name Regulations under the Canadian Environmental Protection Act, 1999. This method is useful in that it is systematic and its application to develop a GCN as required under the HPR and HMIRA is considered acceptable by Health Canada.

A less systematic method is to mask the identity, position or number of functional groups on the chemical molecule. For example:

• The position and/or number and/or type of constituents can be masked
• The parent structure and its primary functional group can be masked
• The presence and number of other functional groups can be masked
• Any combination of the above mentioned options

IUPAC has published documents on class names (4) which can be used to replace the parent structure and functional groups on the molecule.

The GCN should retain some aspect of the chemical structure, as well as one or more functional groups or radicals. For example, a salt should be identified and not masked if there are hazards very specific to its metal cation that are required to be disclosed on the SDS or label.

Examples of GCNs

1. CAS Name: Sodium dimethylbenzene sulphonate (CAS no: 1300-72-7)

   

   Figure 31 - Text description

   The chemical structure of Sodium dimethylbenzene sulphonate

   The GCN could be developed by starting with the CAS name and masking the following:

   • Na+: the presence of the cation, or salt
   • The two CH₃ groups (alkyl groups): the specific constituents, the number of constituent groups, position of the constituent groups (positions "5" and "6" on the benzene ring), or even the presence of the constituent groups
   • Benzene ring (aryl group): the parent compound

   Possible GCNs include: dimethylbenzene sulphonate (salt)

   • dialkylbenzenesulphonate sodium salt dialkylarylsulphonate sodium salt dialkylarylsulphonate (salt) alkylarylsulphonate (salt)
   • substituted arylsulphonate (salt) dimethylbenzene inorganic acid, sodium salt

2. CAS Name: Hexanoic acid, 2-ethyl-, zinc salt (CAS no: 136-53-8): 2(2-(C2H5)C6H10O2)Zn

   

   Figure 32 - Text description

   Figure 32. Hexanoic acid, 2-ethyl-, zinc salt
   Figure 32. – Alternative text
   The chemical structure of Hexanoic acid, 2-ethyl-, zinc salt

   The name Hexanoic acid, 2-ethyl-, zinc salt could be used to start, or zinc bis(2-ethylhexanoate), where the bis indicates two ethylhexanoate components could be used, and the following could be masked:

   • Zn2+: the presence of the cation, or salt
   • The ethyl (C2H5) group (alkyl group): the specific constituent, position of the constituent group (the "2" position), or even the presence of the constituent groups
   • Hexanoic acid (carboxylic acid group): the parent compound

   Possible GCNs include:

   • salt of an alkyl substituted carboxylic acid
   • alkylcarboxylic acid, zinc salt.

   Keeping the identity of zinc salt would allow the linking of hazards to the organic functional group and structural features of the compound.

Common errors in developing a GCN

1. Terms for product/chemical use

   Terms such as dye, surfactant (even if qualified with the type such as anionic, cationic, or nonionic), catalyst, binder, colorant, emulsifier, inhibitor, or organic solvent are descriptors of product use and do not provide sufficient information on the chemical itself.

2. Pseudo chemical names or misleading names

   Syllables or masked syllables from the conventional chemical nomenclature may misrepresent a chemical structure. This includes using prefix and suffix syllables in the GCN, when these radicals or functional groups are not present in the molecule.

   Juxtaposing a series of simple chemical terms such as "oxo-alcohol ether sulfate" or using creative phrases such as "oxygenated ketone" could cause confusion when considering the chemical functionality.

   

   Figure 33 - Text description

   The order of the components of the name should usually relate to the actual chemical name. For example:

   "alkylaryl halide" for chloromethylbenzene would be confusing as it indicates the halide is on the aryl (benzene) group (in this case, the GCN would be more correctly arylalkylhalide or haloalkylarene).

   Where the precise structure of the reaction product is known, developing a GCN based on precursor or starting ingredient(s) of a reaction would be too ambiguous.

3. Long descriptive phrases or a list of atoms.

   Long descriptive phrases may be too general. For example, referral to a specific chemical ingredient as a "long chain hydrocarbon containing sulphur and nitrogen" gives no indication of whether the hydrocarbon is saturated, unsaturated, branched or linear; does not indicate whether the sulphur and nitrogen only have hydrogen attached to them or something more complex; and does not indicate whether sulphur or nitrogen is the main functional group, such as an amide or imide, or sulfonate or sulfoxide.

References for this section of the guide

1. ChemID, National Library of Medicine, National Institute of Health. Available at: http://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp
2. CRC Handbook of Chemistry and Physics, 96th Edition, Published by CRC Press, Editor(s):William M. Haynes, 2015
3. The Merck Index, 15th Edition, Royal Society of Chemistry, 2013
4. International Union of Pure and Applied Chemistry, (1995) Glossary of Class Names of Organic Compounds and Reactive Intermediates Based on Structure. Pure &App/. Chem., Vol. 67, Nos 819, pp. 1307-1375.