Rapid Screening of Substances of Lower Concern Results of the Screening Assessment Environment Canada Health Canada April 2013

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Table of Contents

• Synopsis
• Introduction
• Scope of the Rapid Screening Approach
• Summary of the Rapid Screening Approach – Ecological Considerations
• Assessment of Potential to Cause Ecological Harm
• Summary of Results from Ecological Considerations
• Summary of Ecological Uncertainties
• Summary of the Rapid Screening Approach – Human Health Considerations
• Assessment of Potential to Cause Harm to Human Health
• Uncertainties in the Evaluation of Risk to Human Health
• Further Activities
• Conclusion
• References
• Appendices

Synopsis

Based on the results from the categorization of substances on the Domestic Substances List (DSL) a subset of 1066 substances was identified for application of a rapid screening approach. These substances included those that met categorization criteria as being inherently toxic (ecological) and either persistent or bioaccumulative (but not both), in addition to being in commerce in low quantities (maximum use in Canada of 1000 kg per year based on 1986 data) and are therefore expected to be of lower concern.

In considering this group of substances, this rapid screening approach involves four main steps in identifying substances that warrant further evaluation of their potential to cause harm. The first step consists of determining if substances are currently being addressed under other assessment activities. The second step involves applying different ecological exposure scenarios using assumptions that are protective of the environment. The third step involves a process to identify whether or not a substance appears on any of a wide range of different lists or in information sources relating to ecological hazard or exposure. This flags substances that have been identified by domestic or international initiatives as being of greater concern due to their hazard properties, or which may now be in commerce at greater quantities than had been considered to be the case based on the available information.

Substances not identified as requiring further assessment due to ecological concerns are evaluated in the fourth step to determine whether a given substance is of potential concern from a human health perspective. A key element of characterization of potential risk for human health is determination of potential for exposure to the general population. Substances assumed to be in commerce in Canada at ≤ 1000 kg are considered to result in potential exposure to the general population if there is evidence of direct exposure (e.g., exposure from products, food additives). Otherwise it is concluded that the substance is unlikely to cause harm to human health at current levels of exposure.

In total, 472 substances were identified through the four steps of the rapid screening approach as requiring further assessment, including some that are currently being addressed under other assessment activities. A further 61 substances were withdrawn from this process for a variety of additional reasons (such as that they had since been deleted from the DSL or that they no longer met the low volume criteria for rapid screening).

For the remaining 533 substances, the screening assessment, conducted pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999), indicated that the historical or current (for those substances included in the 2009 DSL Inventory Update) use patterns and quantities are unlikely to result in ecological or human health concerns in Canada. All 533 substances had estimated exposure values below the level of concern. Furthermore, evaluation of a wide range of information sources did not identify additional ecological flags. From a human health perspective, exposure to the general population to the 533 substances is expected to be negligible and therefore the substances are unlikely to cause harm to human health at current levels of exposure.

Based on the results of this screening assessment, it is concluded that the 533 substances listed in appendix C are not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity, that constitute or may constitute a danger to the environment on which life depends, or that constitute or may constitute a danger in Canada to human life or health. It is therefore concluded that these 533 substances do not meet the criteria as set out in section 64 of CEPA 1999.

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Introduction

The Canadian Environmental Protection Act, 1999 (CEPA 1999) (Canada 1999) requires the Minister of the Environment and the Minister of Health to conduct screening assessments of substances that have met the categorization criteria set out in the Act to determine whether these substances present or may present a risk to the environment or human health^[1].

Following the categorization of substances on the Domestic Substances List (DSL), the Government of Canada has identified a subset of the substances that are persistent and inherently toxic to non-human organisms (PiT(eco)), or are bioaccumulative and inherently toxic to non-human organisms (BiT(eco)) based on categorization, and that are believed to be in commerce in Canada at a maximum of 1000 kg per year across the country. None of these substances met categorization criteria with respect to human health.

The Government of Canada has developed a rapid screening approach to conduct screening assessments under section 74 for substances that have a low likelihood of meeting the criteria set out in section 64 of CEPA 1999.Under section 64, a substance is considered “toxic” if it is entering or may enter the environment in a quantity or concentration or under conditions that:

The rapid screening approach originally considered 1066 substances, and a draft screening assessment was published for a 60-day public comment period in March 2007. A second draft was published in June 2011 for a second 60-day public comment period given that substantial revisions had been made to the screening approach since 2007. While external comments were taken into consideration, the content and outcome of this screening assessment remain the responsibility of Environment Canada and Health Canada.

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Scope of the Rapid Screening Approach

Substances identified for rapid screening under this approach are those nominated to the DSL (based on quantities imported, manufactured or otherwise in commerce in Canada in 1986) at total quantities ≤ 1000 kg across the country. Since quantities were reported as ranges, the quantity representing the upper boundary of the reported range was used. If the sum from all notifiers exceeded 1000 kg, the substance was not considered as a candidate for this approach. Therefore, substances reported in the range 0-100 kg by 10 or fewer companies are included, as well as substances reported in the range 100-1000 kg by a single company.

The substances being assessed have also been identified as PiT(eco) or BiT(eco) through the categorization process. Those substances that were identified by categorization as being PBiT (substances that are persistent and bioaccumulative and inherently toxic) are excluded from consideration under this approach, due to particular concerns identified for substances having this combination of properties.

Substances that meet the above criteria, but that have already been assessed and managed under CEPA 1999, are not included.

One substance included in the original 2007 draft assessment has been classified as a reproductive toxicant by the European Commission (CAS^[2] RN 14816-18-3) in 2007. This substance is not expected to result in general population exposure, but was removed from the rapid screening approach so that commercial status can be confirmed prior to an assessment decision.

Four substances from the list of substances addressed in the 2007 draft assessment have since been deleted from the DSL and listed on the Non-Domestic Substances List (NDSL), as further searching has indicated that they were not manufactured or imported into Canada during the reporting period for the DSL (1984-1986). As these substances are no longer listed on the DSL (Canada 2008, 2009a), they are subject to the New Substances Notification Regulations, and are excluded from further assessment as existing substances. They are CAS Registry Numbers (CAS RN) 84-77-5, 620-40-6, 1191-15-7 and 16853-85-3.

During the public comment period on the 2007 draft screening assessment report, one company indicated that they are using more than 1000 kg per year of substance CAS RN 32610-77-8.This new use pattern information has resulted in removing this substance from the current assessment as it no longer meets the pre-established quantity limit.

In addition, new information on quantities of certain substances in commerce during the 2008 calendar year was received in response to a Section 71 survey notice issued on October 3, 2009, as part of the first phase of the DSL Inventory Update initiative (Canada 2009b). The survey, which covered approximately 500 chemical substances, included 59 substances from this rapid screening approach. Of these, data submitted by industry stakeholders indicated that 16 substances were manufactured and/or imported in quantities greater than 1000 kg in 2008.Therefore, these 16 substances do not meet the pre-established quantity limit and have been removed from rapid screening. These 16 substances are CAS RNs: 523-31-9, 1345-04-6, 2452-01-9, 3896-11-5, 7446-26-6, 10025-91-9, 13189-00-9, 14059-33-7, 14726-36-4, 25155-23-1, 33908-66-6, 36437-37-3, 53894-23-8, 61617-00-3, 68988-45-4, and 113706-15-3 (see Appendix B, Substances Identified as No Longer Meeting Scope of Rapid Screening Approach).

Additionally, confirmation of DSL quantity data has led to updates in some quantity information used for the exposure scenarios in step 2 of the Rapid Screening approach. As a result, 30 additional substances which were considered in the original draft screening assessment have been removed from this assessment and will be included in future screening assessments (see Appendix B, Substances Identified for Inclusion in Future Rapid Screening Approach), as the DSL Inventory Update data is anticipated to change the proposed status for these substances.

In addition, the re-examination of DSL nomination data for nine substances indicates that the proposed conclusion of ‘requires further assessment’ for these substances is anticipated to change, and they have been removed from this initiative (see Appendix B, Substances Identified for Inclusion in Future Rapid Screening Approach).

This document reports the final results of the screening assessment conducted following a rapid screening exercise of the 1005 substances that are still candidates for this assessment approach.

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Summary of the Rapid Screening Approach – Ecological Considerations

The ecological component of the rapid screening approach uses a series of both qualitative and conservative quantitative steps to efficiently evaluate the likelihood that a substance may cause ecological harm. At each of the steps shown in Figure 1, substances for which there may be potential to cause ecological harm are identified as requiring further screening assessment beyond the rapid screening approach. For those substances that proceed through all steps of the approach without being thus identified, it is concluded that they are unlikely to cause ecological harm and, as such, do not meet the criteria set out in paragraphs 64(a) or (b) of CEPA 1999.

The first step consists of determining if substances are already being addressed under other assessment activities or no longer meet the scope of the rapid screening approach. These substances do not proceed to step 2.

The second step involves applying different scenarios or fate models to estimate environmental exposure. First, two generic aquatic exposure scenarios are considered to identify potential concerns near the point of discharge of a substance to the environment. A regional multi-media model named RAIDAR (Risk Assessment, IDentification And Ranking) is also applied to identify potential concerns in different environmental media, as well as in food chains.

The third step involves a mechanical process to identify whether or not a substance appears on different lists or in information sources relating to hazard or exposure (including quantity in commerce). This flags substances that have been identified by domestic or international initiatives as being of greater concern due to their hazard properties, or which may now be in commerce at greater quantities than originally reported.

Figure 1: Overview of rapid screening approach

Depending on the nature of the information sources, substances flagged by the mechanical process may be concluded as requiring further assessment beyond rapid screening, or may be further evaluated within rapid screening using a “manual process”. The latter involves case-by-case evaluation to decide, for example, whether the specific information in the source that flagged the substance is relevant to the situation in Canada. This may also involve collection and review of information from other sources that are not as amenable to evaluation using a mechanical approach. The manual process involves evaluation of the weight and relevance of information obtained from the full range of sources identified.

A detailed description of the approach is contained in a separate document (Environment Canada 2007a).

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Assessment of Potential to Cause Ecological Harm

In this section, an overview of the results obtained at each step of rapid screening of the substances covered under this rapid screening approach is provided.

Step 1 – Current Assessment Activity

The first step of the approach identified substances that are subject to current assessment activity or that have high hazard flags.

Of the 1005 substances considered at Step 1, 196 substances have been included in groups of substances undergoing assessment under the Chemicals Management Plan (Canada 2011). These include 172 Aromatic Azo- and Benzidine-based substances, 2 boron-containing substances, 7 cobalt-containing substances, 4 phthalate substances, 8 selenium-containing substances, and 1 substituted diphenylamine substance (see Appendix B, Substances Identified as Subject to Other Assessment Activity). These substances are being assessed under that initiative and therefore are no longer considered in this rapid screening approach.

Another two substances were removed at this step. Two substances undergoing rapid screening were found to be structurally similar to substances that were categorized as PBiT. These two substances have CAS RNs 519-73-3 and 62625-30-3 (see Appendix B, Substances Identified as Subject to Other Assessment Activity).Recognizing that PBiT substances are not considered under this rapid screening approach, these two substances were identified as requiring further assessment.

As a result of these exclusions, 809 substances remain eligible for evaluation under rapid screening approach.

Step 2 – Exposure Estimation

In this final assessment, quantity information used in the exposure scenarios was revised as appropriate based on submissions obtained through the DSL Inventory Update initiative (2009), which included 59 rapid screening substances, as well as other confirmation of DSL data.

Generic aquatic scenarios

Two generic exposure scenarios are used to evaluate the potential for releases of a substance to the aquatic environment to cause harm. The first scenario (industrial point-source) considers the release of 5% of the substance from an industrial facility that is involved in manufacturing the substance and/or using it in the preparation of products. A loss of 5% from manufacturing and handling was chosen based on conservative (i.e., protective of the environment) estimates for loss from cleaning of container residues (3%), transfer lines (1%) and process equipment (1%) (US EPA 1992). The second scenario (residential releases to municipal waste-water) considers the down-the-drain release of 100% of the substance that is contained in a consumer product, through multiple point-sources (i.e., municipal waste-water discharges).The basis and assumptions of these conservative exposure scenarios are described in detail in the rapid screening approach document (Environment Canada 2007a).

The industrial releases scenario flagged 146 substances as being of potential concern. The residential releases scenario flagged 77 substances; however these were all flagged by the industrial release scenario as well. These 146 substances (or 18% of the 809 evaluated) were identified by these scenarios as requiring further assessment (see Appendix B, Substances Requiring Further Assessment Identified through the Ecological Approach).

The detailed spreadsheet associated with this report (Environment Canada 2011a) includes the calculations and results from application of these scenarios to each substance.

RAIDAR

The multimedia fugacity-based RAIDAR model accounts for the combined consideration of a substance’s physical/chemical and hazard properties and allows evaluation of potential for harm to organisms in different environmental media as well as in food chains. It also accounts for release of a substance over a larger geographic area through its full life-cycle. The approach and its application to a number of substances on the DSL are described in detail in a report produced by the Canadian Environmental Modelling Centre (CEMC 2007a). The salient features and limitations of RAIDAR in the context of rapid screening are also discussed in Environment Canada 2007a.

As discussed in the above mentioned reports, RAIDAR and similar models are not applicable to all categories of substances encountered on the DSL. Of the 14 chemical categories described in CEMC 2007a, RAIDAR has been applied to substances in five categories – conventional organics; dissociating organic acids; dissociating organic bases; gases; and in volatile organics. Therefore, of the 809 substances evaluated in Step 2, 355 (or 44%) have been modelled using RAIDAR.

As described in Environment Canada 2007a, the Level III fugacity model scenario that assumes 33% release of the substance to each of air, water and soil has been selected for interpretation of RAIDAR results in rapid screening. The outputs from RAIDAR of greatest relevance to this work include the media of concern, the critical emission rate (Ec) and the risk assessment factor (RAF).The Ec is the minimum quantity of a substance that would have to be released to a unit world (a region of fixed dimensions) in one year in order for the most sensitive organism in that world to be exposed to a concentration that could cause a harmful effect. The RAF is the ratio of the actual emission rate to the critical emission rate for the substance. In rapid screening, the quantity of the substance believed to be in commerce is conservatively assumed to be the actual emission rate (i.e., it is assumed that 100% of the substance is released to the environment over its life-cycle).

A spreadsheet associated with the CEMC report includes all input values and results from application of RAIDAR to these substances (CEMC 2007b)^[3]. As with other models, results from RAIDAR depend on the quality and quantity of the available substance-specific data. The CEMC report discusses some specific issues relating to uncertainties in input data. A separate document (Environment Canada 2007b) discusses how the results of RAIDAR were interpreted with these considerations.

In order to identify which substances are unlikely to have the potential to cause ecological harm, it is necessary to select a cut-off value for the RAF.A value of 0.001 was selected, which is equivalent to an uncertainty factor of 1000 (see Figure 2).Selection of this conservative value allows for up to a 1000-fold error in the model results owing to uncertainties in the quantity of the substance in commerce and other model inputs, such as physical-chemical properties. The ability of RAIDAR to discriminate potential for ecological harm based on the characteristics of substances is discussed further in Environment Canada 2007b.

Based on the described model scenario and the selected RAF cut-off value, 20 of the 355 substances that were evaluated using RAIDAR were identified as requiring further assessment, as shown in Figure 2. (There was also an additional substance (CAS 58-39-9) that exceeded the RAF cut-off value, but which was identified for further evaluation through the Manual Process due to receipt of more recent industrial data.) Of these, 16 had also been identified by the generic aquatic scenarios discussed above. Therefore, an additional 4 substances were identified as requiring further assessment.

A total of 150 substances were identified as requiring further assessment based on combined results of generic aquatic scenarios and RAIDAR (substances are included in the list in Appendix B, Substances Requiring Further Assessment Identified through the Ecological Approach).

Figure 2 : Risk Assessment Factor (RAF) results for PiT and BiT substances in commerce at ≤ 1000 kg/year in Canada based on the RAIDAR model (The dashed line represents the RAF cut-off value of 0.001.)

Step 3 – Mechanical Filters and Manual Process

The different sources of information used as mechanical filters are divided in three categories: 1) exposure – quantities, releases and industrial information; 2) hazardous substances lists or substance profiles; and 3) miscellaneous properties and hazards databases. As described in the rapid screening approach document (Environment Canada 2007a), each of the information sources has been allocated a weighting that reflects its relevance to the context of this evaluation. Some sources (such as the High Production Volume (HPV) databases for the US and the OECD) are considered of sufficient relevance that substances that they include are immediately identified under rapid screening as requiring further assessment. Others, that are either considered of lesser relevance or for which more detailed evaluation of substance-specific data contained in the information source is possible, are directed to the manual process stage for a decision to be made based on the weight of the full range of available information.

Appendix A shows the number of substances that have been flagged by each of the mechanical filters for the 1066 substances that were considered for this rapid screening approach. As seen in Appendix A, some mechanical filters have flagged more substances than others. Of the 659 substances being assessed in this step, nineteen of the substances appear on one or more of the six international lists of High Production Volume (HPV) chemicals. As this demonstrates that these substances are in use in high quantities in at least some countries, the assumption that they are currently used in very low quantities in Canada is less certain. For two of the 19 substances that are on an HPV list, recent Canadian data has already been collected, therefore these two substances are further evaluated at the manual process stage. The remaining 17 substances on HPV lists have been identified as requiring further assessment, which will include collection of current information on quantities in commerce in Canada. A total of 335 substances were flagged by mechanical filters, leading to their evaluation at the manual process stage.

Substance-by-substance evaluation at the manual process stage is based on consideration of the weight of available information as to whether the substance may currently be in use in Canada in quantities greater than had been assumed, or if the substance has hazard properties or characteristics that may not have been adequately addressed using the exposure scenarios in step 2.This may involve looking at temporal trends in the quantity of a substance in commerce in other countries.

As a result of this further evaluation, 41 substances were identified as requiring further screening assessment (substances are included in the list in Appendix B, Substances Requiring Further Assessment Identified through the Ecological Approach).A summary of the basis for the decision on each of the 335 substances evaluated using the manual process is presented in the detailed results spreadsheet (Environment Canada 2011a).

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Summary of Results from Ecological Considerations

The results obtained at each step of the screening approach are summarized in Figure 3.A simplified spreadsheet that provides the outcome of each step of the approach for each of the substances may be found in Environment Canada 2011b.

In total, 208 (404 when including substances in the groups being assessed under the Chemicals Management Plan) of the substances evaluated using the ecological rapid screening approach were identified as requiring further screening assessment. A list of these substances is provided in Appendix B (Substances Requiring Further Assessment Identified through the Ecological Approach).The other substances were assessed and concluded to be unlikely to cause ecological harm. The substances were subsequently evaluated using the human health rapid screening approach.

Figure 3: Summary of rapid screening results - ecological considerations

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Summary of Ecological Uncertainties

It is recognized that conclusions resulting from the use of rapid screening have associated uncertainties. However, the use of a wide range of filters (relating to both use quantity and ecological hazard concerns identified for a substance), as well as the use of different conservative exposure scenarios give confidence that substances identified as not requiring further assessment are unlikely to be of ecological concern.The high fraction of these lower concern substances that have been identified by rapid screening as requiring further assessment due to potential ecological concerns (40%) is a reflection of the conservative basis of the approach.

A primary uncertainty in this approach is that the substances identified for rapid screening under this assessment are those nominated to the DSL (based on quantities imported, manufactured or otherwise in commerce in Canada in 1986) at total quantities ≤ 1000 kg across the country. Information sources consulted at step 3 (mechanical filters and manual process) of rapid screening were used to verify whether assumptions regarding current quantities in commerce were appropriate. More recent information has been collected for 59 substances under the first stage of DSL Inventory Update, and has been taken into account in finalising this assessment. Additional DSL Inventory Update information on these substances in the future will verify quantities and reduce uncertainty in the assessment outcome. Accordingly, substances may be subject to further assessment based on new information when available.

Values for physical/chemical and hazard properties derived during categorization of the DSL were used as input for the RAIDAR modelling work. As recognized in documentation associated with categorization, there are uncertainties in these values, in particular, with those that have been estimated using different modelling approaches. Extreme values that were estimated by models were replaced by limiting values of physical/chemical properties or alternatively-derived toxicity values, prior to using them as input for RAIDAR modelling as part of rapid screening (CEMC 2007a).A supplementary document (Environment Canada 2007b) further discusses some of these factors in the context of rapid screening.

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Summary of the Rapid Screening Approach – Human Health Considerations

A process was used to determine if substances within the rapid screening approach of substances of lower concern warranted further assessment from a human health perspective (Figure 4). None of these substances met categorization criteria with respect to human health and none of the substances identified for consideration with this approach were identified as posing a high hazard to human health based on classifications by other national or international agencies for carcinogenicity, genotoxicity, developmental toxicity or reproductive toxicity.

Figure 4: Overview of Rapid Screening Approach - Human Health Considerations

A key element of characterization of potential risk to human health is determination of potential for exposure to the general population. Substances assumed to be in commerce in Canada at ≤ 1000 kg were considered to result in potential exposure to the general population if there was evidence of direct exposure (e.g., exposure from products, food additives, etc.). Otherwise, exposure to the general population was considered to be negligible and it can be concluded that that substance is unlikely to cause harm to human health at current levels of exposure and, as such, does not, at this time, meet the criterion set out in paragraph 64(c) of CEPA 1999.

Given the assumed quantities in commerce in Canada (≤ 1000 kg) of these substances, indirect exposure to the general population from environmental media (air, water, soil) is not expected to be significant. Release of a substance to specific environmental media (i.e., air, water, soil) depends on factors such as where the substance is released, physical/chemical properties, etc. Conservative modelling estimates using a fugacity based modelling tool for applicable substances ChemCan 2003, indicate that assuming 100% release of a substance (i.e., the maximum possible release for these substances of 1000 kg) to either air, water or soil, potential exposures would be predicted to be less than 10^-6 mg/kg bw/day (i.e., <1 ng/kg bw/day). This represents a negligible exposure potential from indirect sources for these substances.

Depending on the use of the substance, direct exposure to the general population is also possible. Considerations for determination of direct exposure potential are described below and outlined in Figure 5.

Figure 5: Considerations for the determination of direct human exposure potential to chemical substances through direct use

The term “direct use” refers to the use of a chemical substance that is directly, or as part of a mixture, a product, or a manufactured item, sold to or made available to Canadians for their use.

The term "direct use" does not include exposures from chemical products used by workers in an industrial setting or other workplace.

A user is considered to be anyone from the general public who has access to a product that is advertised, imported or sold in Canada^[4].

To determine if a substance is used in or present in a product used by Canadians, the following resources were consulted:

• Information from a mandatory s.71 survey of information collected under the Canadian Environmental Protection Act (where available); e.g. Phase One of the Domestic Substances List Inventory Update (Canada 2009b)
• Health Canada’s Cosmetic Notification System (CNS 2010)
• Health Canada list of Food Additives (Division 16 of the Food and Drug Regulations) (Canada 1978) [Accessed November 2010]
• Health Canada’s Natural Health Products Ingredients Database (NHPID2010)
• Health Canada’s Licensed Natural Health Products Database (LNHPD 2010)
• Health Canada’s Drug Product Database (DPD 2010)
• Everything Added to Food in the United States Database (EAFUS 2010)
• Household Products Database (HPD 2010)
• Hazardous Substances Data Bank (HSDB c1993-2008)
• Pest Management Regulatory Agency Product Information Database (PMRA 2010a)
• Pest Management Regulatory Agency List of Formulants (PMRA 2010b)
• National and international assessments and databases
• Other publicly available resources

Based on the information identified from these resources, together with other available information on the substance, the following considerations were used to determine potential for direct exposure:

1. Substances to which direct exposures to the general population are not expected include, but are not limited to, substances:
   a. used only as intermediates in the manufacturing process,
   b. used only for industrial use, or
   c. used only for research purposes
   
2. Substances with potential for direct exposure to the general population include those that are present, either intentionally or unintentionally, in products or manufactured items that are commonly used by Canadians. These include, but are not limited to, substances used in:
   • products intended for use by children, including manufactured items such as plastic or wooden toys
   • personal care products,
   • commercial paints and inks,
   • commercial adhesives,
   • hobby activities or Do-It-Yourself products,
   • clothing, fabric and other textiles, including bedding and furniture
   • cleaning products,
   • food additives, or
   • fragrances
     
3. Information on potential for the substance to migrate from products

Considerations for determining whether a substance is migrating out of the final product include the type of product that the substance is present in, the substance’s functional use in that product, as well as the substance’s physical-chemical properties. For example, direct exposure would not be expected to occur for a substance used as a curing agent in a polymer as the substance would be reacted into the stable matrices of the cured polymer and would therefore not typically be available for migration.

If this information is not known for a substance, it was assumed that the substance may be migrating out of the final product, which may lead to direct exposure for users.

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Assessment of Potential to Cause Harm to Human Health

Of the 601 substances examined from a human health perspective, 68 substances were identified as having the potential to result in exposure to the general population and therefore further assessment of exposure and hazard potential of these substances will be completed to determine if they meet the criteria set out in section 64 of CEPA 1999. Substances with potential for exposure to the general population and therefore requiring further assessment are included in Appendix B (Substances Requiring Further Assessment Identified through the Human Health Approach).

Exposure to the general population was considered to be negligible for the remaining 533 substances. As exposure to the general population is considered negligible, it is concluded that the substances are unlikely to cause harm to human health at current levels of exposure and so do not meet the criterion set out in paragraph 64(c) of CEPA 1999. The list of the substances that do not meet the criteria set out in section 64 of CEPA 1999 is provided in Appendix C.

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Uncertainties in the Evaluation of Risk to Human Health

As stated in the summary of ecological uncertainties, a primary uncertainty in this approach is that the substances identified for rapid screening under this assessment are those nominated to the DSL (based on quantities imported, manufactured or otherwise in commerce in Canada in 1986) at total quantities ≤ 1000 kg across the country. If substances are present at higher quantities at the present time, they may warrant further assessment for indirect exposure potential to the general population. However, up-to-date information was used to identify potential sources of direct exposure. The recent information that has been collected for 59 substances under the first stage of DSL Inventory Update has been taken into account in finalising this assessment and reduces uncertainty for those substances. Additional DSL Inventory Update information on these substances in the future will verify quantities and reduce uncertainty in the assessment outcome. Accordingly, substances may be subject to further assessment based on new information when available.

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Further Activities

It is important to recognize that the Government of Canada identifies substances for assessment based on a number of different considerations. Substances for which it is concluded, based on the outcome of the rapid screening approach and other considerations, that they do not meet the criteria in section 64 of CEPA 1999 remain subject to re-assessment if information is identified that indicates that further evaluation of the substance is warranted. Examples of the types of information that may trigger further evaluation of a substance include, but are not limited to:

• Evidence of higher quantities in commerce.Since the rapid screening approach is driven, in part, by information on the quantity in use, updated information to suggest that higher quantities of a substance are now in use could indicate that a substance should be subject to further evaluation.
• Evidence of higher releases. The exposure scenarios used assumptions that are expected to be conservative for most substances. Updated information indicating that the assumed conditions are not protective for a particular substance owing to its routine handling and use could indicate that a substance should be the subject of further evaluation.
• Evidence of ecological or human exposure.Biomonitoring/monitoring data demonstrating the detectable presence of a substance in environmental media or humans could indicate that a substance should be the subject for further evaluation
• Evidence of other possible ecological risk.Information that was not considered in the rapid screening approach, but that could be of significance in establishing an ecological risk for a substance, could indicate that a substance should be subject to additional assessment.
• Evidence that a substance is highly persistent and bioaccumulative. Since substances categorized as PBiTs are not candidates for the rapid screening approach, any information to suggest that the substance is PBiT could trigger further evaluation of the substance.
• Evidence that a substance is highly hazardous.Information that indicates that the substance is highly hazardous could indicate that a substance should be subject to further evaluation.
• Identification as part of a category/group undergoing assessment. If the substance is part of a group that is prioritized for a category assessment at some time in the future, the substance may be subject to this further evaluation.
• Evidence of changes in use pattern.Information indicating new uses associated with the substance with potential for direct exposure to the general population could indicate that a substance should be subject to further evaluation.

Information of these types may be identified from a number of different sources, including:

• direct submission of information by stakeholders;
• research, monitoring and DSL update activities taking place under the Chemicals Management Plan;
• other assessment or regulatory activities in Canada or in foreign or international fora.

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Conclusion

Based on the results of this screening assessment, it is concluded that the 533 substances listed in Appendix C are not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity, that constitute or may constitute a danger to the environment on which life depends, or that constitute or may constitute a danger in Canada to human life or health.

It is therefore concluded that the 533 substances listed in Appendix C do not meet the criteria as set out in section 64 of CEPA 1999.

These substances have been or will be included in the previous (2009) or upcoming Domestic Substances List inventory update initiatives to verify the assumptions made regarding volumes in use in Canada.

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References

Canada. 1978. Food and Drug Regulations, C.R.C., c. 870, s. B.16.100.

Canada. 1999. Canadian Environmental Protection Act, 1999. S.C., 1999, c. 33.

Canada. 2008. Canadian Environmental Protection Act, 1999: Order 2007-66-11-01 Amending the Domestic Substances List, Canada Gazette, Part II, Vol. 142, No. 13, 25 June 2008, SOR/2008-184.

Canada. 2009a. Canadian Environmental Protection Act, 1999: Order 2008-66-04-01 Amending the Domestic Substances List,Canada Gazette, Part II, Vol. 143, No. 26, 23 December, 2009, SOR/2009-337.

Canada. 2009b. Canadian Environmental Protection Act, 1999: Notice with respect to certain inanimate substances (chemicals) on the Domestic Substances List, Canada Gazette, Part I, Vol. 143, No. 40, 3 October, 2009.

Canada. 2011. Canadian Environmental Protection Act, 1999: Announcement of planned actions to assess and manage, where appropriate, the risks posed by certain substances to the health of Canadians and the environment, Vol. 145, No. 41, 8 October, 2011.

CEMC. 2007a. Risk Prioritization for a Subset of Domestic Substances List Chemicals Using the RAIDAR Model. Report prepared by the Canadian Environmental Modelling Centre, Trent University, ON, for the Existing Substances Division, Environment Canada, Gatineau, QC, Canada.

CEMC. 2007b. Spreadsheet of results associated with the report “Risk Prioritization for a Subset of Domestic Substances List Chemicals Using the RAIDAR Model”. Prepared by the Canadian Environmental Modelling Centre, Trent University, ON, for the Existing Substances Division, Environment Canada, Gatineau, QC, Canada.

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Appendices

• Appendix A: Number of Substances Flagged by each Mechanical Filter (results from 1066 substances considered for rapid screening)
• Appendix B: Substances Identified as Requiring Further Assessment
• Appendix C: Substances Identified as Not Meeting the Criteria Under Section 64of CEPA 1999

Footnotes

^[1] A determination of whether one or more of the criteria of section 64 are met is based upon an assessment of potential risks to the environment and/or to human health associated with exposures in the general environment. For humans, this includes, but is not limited to, exposures from ambient and indoor air, drinking water, foodstuffs, and the use of consumer products. A conclusion under CEPA 1999 is not relevant to, nor does it preclude, an assessment against the hazard criteria specified in the Controlled Products Regulations, which is part of the regulatory framework for the Workplace Hazardous Materials Information System.
^[2] The Chemical Abstracts Service Registry Number (CAS RN) is the property of the American Chemical Society and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the government when the information and the reports are required by law or administrative policy, is not permitted without the prior, written permission of the American Chemical Society.
^[3] It should be noted, however, that when the RAF was initially calculated, it was assumed that the quantity in commerce for all substances was 316 kg (the geometric mean of 100 kg and 1000 kg), and it is this value that appears in the spreadsheet (CEMC 2007b).The detailed results spreadsheet for rapid screening (Environment Canada 2008a) provides an RAF value for each modelled substance that has been recalculated based on the actual quantity reported to be in commerce in Canada.
^[4] Health Canada Website