Approach to nanoscale forms of substances on the domestic substances list: chapter 2

2. Context

2.1 Chemicals management in Canada

Chemical substances in Canada are regulated under the Canadian Environmental Protection Act, 1999 (the act), which provides the authority to collect information, to assess and to manage risks to the environment and human health. Substances are defined as either existing or new using the Domestic Substances List^Footnote2 (DSL), which determines if a substance is considered in commerce in Canada or is new to the Canadian market. Existing substances are assessed and managed under the act through the Chemicals Management Plan (CMP). Launched in 2006, the CMP builds on previous initiatives to prioritize and take action on substances which may be harmful.^Footnote3 New substances are regulated under the New Substances Notification Regulations (Chemicals and Polymers) (the regulations), which prescribe data requirements needed to conduct a pre-market assessment before a substance can be imported into or manufactured in Canada.^Footnote4

2.2 Nanomaterials

Nanomaterials which are new to the Canadian market must undergo a pre-market evaluation to assess the potential risks to the environment and human health. To date, Environment Canada and Health Canada have conducted a limited number of assessments of new nanomaterials under the current regulatory framework of the regulations. Existing nanomaterials generally have not been considered under the act; therefore, this approach to address nanoscale forms of substances on the DSL is proposed.

For the purposes of this consultation document, nanomaterials are substances that are manufactured at or within the nanoscale (1-100 nanometres, inclusive), or have internal or surface structures at the nanoscale. Substances may also be considered nanomaterials if they are smaller or larger than the nanoscale in any dimension and exhibit one or more nanoscale properties/phenomena. Nanoscale properties/phenomena refer to properties that are attributable to the size of the substance and size effects.^Footnote5 For example, nanoscale gold can act as a catalyst compared to its non-nanoscale form, which is inert. Nanomaterials may also demonstrate different electrical, magnetic or optical properties than their non-nanoscale forms. Often these properties cannot be predicted based on extrapolation from the non-nanoscale form.

Environment Canada and Health Canada do not intend for this approach to target substances at or within the nanoscale that do not demonstrate different properties/phenomena.^Footnote6 For example, organic pigments typically do not exhibit nanoscale properties/phenomena.^Footnote7 These types of substances are already considered under the regulatory regime for assessment and management of chemicals under the act.

2.3 Domestic

As described in the New Substances Program Advisory Note 2014-02, substances, including nanomaterials, not appearing on the DSL are considered new to Canada and may be subject to notification under the Regulations. Substances listed on the DSL do not require notification under the Regulations unless they are subject to the Significant New Activity (SNAc) provisions of the Act, as indicated with an “S flag” on the DSL.^Footnote8

The DSL lists substances by their Chemical Abstracts Service Registry Number (CAS RN). The assignment of CAS RNs is generally based on the chemical composition of a substance. CAS RNs do not distinguish between substances with the same chemical composition but made up of particles of different sizes (for example, non-nanoscale particles versus nanoscale particles), nor do they take into account differences in properties between the nanoscale and the non-nanoscale forms of a substance. The nanoscale forms of substances on the DSL (existing nanomaterials) are, therefore, generally considered to be existing substances and are not notifiable under the regulations.^Footnote9

The potential novel properties of existing nanomaterials generally have not been considered as part of the risk assessments conducted under the act, and as a result, the potential risks to the environment and to Canadians have not been examined. When the DSL was created, the nanoscale forms of substances were not considered in the criteria for the substance nomination process; however, some substances may now be identified as nanomaterials. Consequently, some nanomaterials may already have been in commerce in Canada for several decades while some may only have entered into commerce more recently. Others could be manufactured or imported into Canada in the future. Environment Canada and Health Canada want to ensure that existing nanomaterials are addressed, as some may require further action to determine if they pose any potential risk to the environment or to human health.

2.4 International

In 2013, the Organisation for Economic Co-operation and Development (OECD) Council issued a Recommendation on the Safety Testing and Assessment of Manufactured Nanomaterials:

Consistent with the OECD Recommendation, the approach proposed in this consultation document works within Canada’s current legislative and regulatory regimes to address existing nanomaterials. Nanomaterials that are not covered by a CAS RN on the DSL are subject to the Regulations, and clarifications are made as needed to address nanomaterials (for example, via the publication of New Substances program advisory notes^Footnote11). Similarly, the act provides the necessary legislative authority to gather and examine information on nanoscale forms of substances on the DSL, to inform the risk assessment, as required, and the potential risk management activities with those substances. Other jurisdictions, such as Australia, the United States (U.S.) and the European Union, also address existing nanomaterials under their current legislative and regulatory frameworks. In particular, the United States Environmental Protection Agency regulates nanomaterials under the authority of the Toxic Substances Control Act and is developing an information-gathering rule to require submission of certain information to aid understanding of the potential environmental and health effects of nanomaterials.

Canada has been working at the international level through various initiatives including the Canada-United States Regulatory Cooperation Council (RCC) Nanotechnology Initiative and the OECD Working Party on Manufactured Nanomaterials (WPMN). The aims of such fora are to improve the scientific knowledge of nanomaterials and to use that knowledge to develop consistent risk assessment approaches for nanomaterials. Outcomes and information from these and other international initiatives will be used to inform the proposed approach to existing nanomaterials in Canada.

For example, some knowledge has been gained on the commercial uses of nanomaterials in Canada and the United States under the RCC Nanotechnology Initiative. Targeted consultations were conducted with certain industry stakeholders via a Technical Team on nanomaterial uses currently or soon to be commercially available in Canada and the U.S. This information was summarized in the form of a Nanomaterials Use Matrix. In addition, a classification scheme was developed for nanomaterials based on their chemical composition. This scheme could help to identify which classes of nanomaterials behave differently from their non-nanoscale forms (i.e., those engineered to exploit a nanoscale property/phenomenon).^Footnote12 Furthermore, a significant body of human health and environmental toxicology data on a set of 13 nanomaterials has been gathered under the OECD WPMN Sponsorship Programme.^Footnote13