Approach under the Canadian Environmental Protection Act, 1999 to address polymers on the Domestic Substances List that were identified as priorities during categorization

Environment Canada
Health Canada
December 2014

(PDF Format - 940 KB)

Table of Contents

• 1. Purpose
• 2. Background
• 3. Description of the approach for polymers
  • 3.1. Identification of candidate substances
  • 3.2. Preliminary data collection through the Domestic Substances List Inventory Update (DSL IU) initiative
  • 3.3 Substances for which commercial activity greater than 1000 kg/year was not reported in the DSL IU ­ candidates for polymer rapid screening
  • 3.4. Substances for which commercial activity greater than 1000 kg/yr was reported in the DSL IU
    • 3.4.1 Information gathering to support risk assessment
    • 3.4.2 Evaluation
• 4. References
• Appendix 1: Flowchart for the approach to address polymers
• Appendix 2: List of candidate polymers on the DSL to be considered in the approach
• Appendix 3: List of masked substances to be considered in the approach

1. Purpose

This document describes the approach being used by Environment Canada and Health Canada to address polymers on the Domestic Substances List (DSL) that were identified as priorities during the categorization process.

2. Background

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 to human health.

Upon completion of categorization in September 2006, approximately 4300 substances were identified as priorities for further action. Polymers account for a substantial portion of the substances identified as priorities, and the Government of Canada has developed an approach for conducting screening assessments under the Chemicals Management Plan (CMP) to determine whether these polymers meet 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:

1. have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
2. constitute or may constitute a danger to the environment on which life depends; or
3. constitute or may constitute a danger in Canada to human life or health.

Polymers are a unique class of substances, where the same Chemical Abstracts Service registry number (CAS RN) can be used to describe substances that have different molecular weights, toxicity, and physical and chemical properties. Therefore, a tailored approach was developed to address the complexity of the polymers assessment.

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3. Description of the approach for polymers

The approach draws on existing expertise within Environment Canada and Health Canada, as well as on international work on the regulation of polymers. The initial proposed approach, which was first published as a consultation document in March 2012, was subject to a 60-day public comment period.  While external comments were taken into consideration, the final content and outcome of the approach for polymers remain the responsibility of Health Canada and Environment Canada.

Key elements of the approach are highlighted in the following sections, and a flowchart illustrating the full approach is provided in Appendix 1.

3.1. Identification of candidate substances

Candidate substances for the approach must meet each of the following three criteria:

1. Listed on the DSL and identified by the Government of Canada as a priority, having met environmental and/or human health categorization criteria, or criteria for other human health priorities.
2. Meets the definition of a polymer, as described in subsection 1(1)^Footnote[1] of the New Substances Notification Regulations (Chemicals and Polymers) (Canada 2005).
3. Not previously addressed under CEPA 1999 (for example, Challenge, Substance Groupings Initiative, or other assessment activities, etc.).

Applying these criteria to the 4300 substances results in 603 candidate substances being identified (see Appendices 2 and 3). If a candidate substance is found not to meet the definition of a polymer after data gathering activities, it will be excluded from the polymer approach and assessed as a chemical under other CMP initiatives. The Government of Canada recognizes that a single CAS RN may represent multiple polymers which have the same structural repeating unit(s), but different overall molecular weight. It is, therefore, conceivable that one CAS RN from the candidate list may represent multiple versions of the same polymer, or in some jurisdictions, a chemical. The determination of whether a substance meets the definition of a polymer under the New Substances Notification Regulations (Chemicals and Polymers) [NSNR (Chemicals and Polymers)] (Canada 2005) will be based on data collected during information gathering activities.

The approach described in this document applies to polymers only; monomers will be considered through other assessment activities as needed.

3.2. Preliminary data collection through the DSL Inventory Update (DSL IU) initiative

Information gathering for the 603 candidate substances will occur in stages. Stage one consisted of preliminary information gathering through a section 71 survey as a part of Phase 2 of the DSL IU initiative, launched in December 2012 (Canada 2012). Information submitted in response to the DSL IU informed the Government of Canada as to whether a candidate substance is in commerce in Canada in a quantity above the reporting threshold of 1000 kg per calendar year used for polymers in the DSL IU survey, but did not indicate the actual quantity in commerce. This reporting threshold is equivalent to the threshold for notification of polymers under the New Substances Program. Further stages of information gathering will take place at a later date and will involve the collection of polymer-specific information for the substances identified as being in Canadian commerce, as necessary. This may include exposure-related information, physical and chemical data, and toxicity data.

The next steps in the approach differ, depending on whether or not commercial activity greater than 1000 kg/year was reported in the DSL IU initiative.

3.3 Substances for which commercial activity greater than 1000 kg/year was not reported in the DSL IU – candidates for polymer rapid screening

A candidate polymer will be considered “not in commerce” at the reporting threshold of 1000 kg per calendar year if the DSL IU survey results indicate no report of commercial activity (import or manufacture) above the reporting threshold. For these low volume polymers, the likelihood of exposure in Canada resulting from commercial activity is expected to be low.

Due to the low likelihood of exposure, these polymers are suitable candidates for polymer rapid screening in order to determine if there are potential risks to the environment and the general population.

To determine potential environmental exposure, the following will be considered:

• Water extractability;
• Analogue physical-chemical data (polymers previously assessed under CEPA 1999 or publicly available data);
• Estimated data (model outputs for representative low molecular weight polymers); and
• All available information on use and exposure of the polymer

The use of water extractability in this approach to assess the environmental concerns for polymers is consistent with the assessment approach taken for new polymers under the NSNR (Chemicals and Polymers)(Canada 2005). Although water extractability data are preferred to assess the potential availability of polymers in the environment, analogue physical-chemical data will be considered in the absence of such data. This includes, but is not limited to, data for polymer average molecular weight (Mn), physical state, or adsorption potential. There is a possibility (for certain low molecular weight polymers) that estimated data from computer models may be used in some cases to fill data gaps and assist with a determination of environmental exposure. This type of information will be used with caution, after applying professional judgement to determine the applicability to the type of polymer being examined.

To determine potential exposure to the general population, Health Canada will consider if available information indicates that use of the polymer in Canada that would lead to direct exposure. At low volumes of commercial activity (i.e., equal to or less than 1000 kg/year), significant exposure via environmental media (that is, indirect exposure) is not expected. To evaluate potential exposure from other sources, Health Canada will consult a variety of information resources consistent with those previously used in rapid screening approaches under the CMP (Canada 2013, 2014). Information resources will include Canadian and relevant foreign regulatory databases, national and international assessments, and other publicly available data resources. Potential for direct exposure will be evaluated through the use of a polymer that is sold to or made available to Canadians as part of a mixture, a product, or a manufactured item.

Polymers that are found to have low exposure potential to the environment or the general population during rapid screening will not receive further evaluation. These polymers will be proposed not to meet any of the criteria in section 64 of CEPA 1999, as exposure resulting from these substances is not expected. No further action would be taken on such polymers at this time.

During polymer rapid screening, polymers associated with a potential source of exposure to the general population will undergo a hazard screening. They will be screened against a set of criteria that are indicative of polymers likely to pose a low hazard to human health. The low hazard criteria will include the following, but additional information may also be considered:

1. The polymer must not be classified as carcinogenic, mutagenic, or toxic to reproduction (CMR) by other international agencies;
2. The polymer must be either
   1. a low concern polyester consisting only of monomers listed in Schedule 8 of the NSNR (Chemicals and Polymers); or
   2. a polymer that contains functional groups considered to be non- reactive in environmental and/or biological settings.

Taking into consideration their low volume, polymers that meet the low hazard screening criteria and polymers that are of low ecological concern are considered likely to pose a low risk to the environment and human health. These low risk polymers would be proposed not to meet any of the criteria in section 64 of CEPA 1999. No further action would be taken on such polymers at this time.

Polymers that do not meet the screening criteria for low hazard and for which potential sources of exposure to the environment or the general population have been identified will undergo further information gathering to inform the assessment.

3.4. Substances for which commercial activity greater than 1000 kg/yr was reported in the DSL IU

Polymers that are found to be in commerce through the DSL IU initiative in a quantity above the reporting threshold are more likely to have a potential for exposure. Available information for these polymers will be reviewed and the polymer may be subject to a second stage information gathering initiative.

3.4.1 Information gathering to support risk assessment

Information gathering through Phase 2 of the DSL IU was mandatory for stakeholders that import or manufacture the surveyed polymers at quantities greater than 1000 kg/year, however information on specific amounts imported or manufactured, uses, molecular weight, as well as toxicological effects were not required to be provided at that time. Depending on the nature of the data required, further information collection may take the form of a mandatory section 71 survey or a voluntary approach for those substances identified to be in commerce. The information gathering will be designed to obtain substance information from the importer and/or manufacturer of the polymer(s). Additional consultations on the survey design and data requirements will occur before a mandatory survey is implemented.

Any proposed survey would allow for flexibility in information gathering facilitating efficient information collection. Where applicable, respondents would be asked to provide information similar to that required for Reduced Regulatory Requirement (RRR)^Footnote[2] polymer evaluation. Meeting RRR criteria is generally considered as an indication of low hazard. In addition, respondents would be encouraged to provide any readily available toxicological information.

3.4.2 Evaluation

The remaining polymers in commerce at greater than 1000 kg will be evaluated in screening assessments in order to determine whether they meet any of the criteria in section 64 of CEPA 1999. As with other assessment approaches, polymers subject to screening assessments may be assessed individually, as a group or as a class. In addition, some polymers imported and or manufactured at greater than 1000 kg/year may be assessed through a refined polymer rapid screening approach.

Polymers will be addressed under one assessment approach, regardless of whether multiple forms are possible for the same CAS RN. Professional judgement as well as information on the substance identity and available resources will be used to determine the applicable assessment approach.

For polymers that have various molecular weight ranges under the same substance name, depending upon the available information, it may be considered appropriate to use information on the form with the lowest expected molecular weight as a conservative approach to facilitate the characterization of its properties.

For some polymers, the Government of Canada may conduct an RRR evaluation to determine whether the reported polymer meets the criteria for RRR using information submitted. If the RRR polymer criteria are met, that form of the polymer would be proposed not to meet any of the criteria in section 64 of CEPA 1999 based on anticipated low hazard.

When the risk assessment concludes that a polymer meets one or more of the criteria in section 64 of CEPA 1999, appropriate risk management will be proposed. For a polymer that does not meet any of the criteria in section 64 of CEPA 1999, it would be proposed that the Government of Canada take no further action at this time as the CEPA measure from section 77 of CEPA 1999. If the polymer does not meet any of the criteria in section 64 of CEPA 1999 but is a substance of potential concern, options on how best to monitor changes in the use profiles of these polymers will be investigated.

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4. References

Canada. 1999. Canadian Environmental Protection Act, 1999. S.C., 1999, c. 33, Canada Gazette, Part III, vol. 22, no. 3. Available from:  http://www.gazette.gc.ca/archives/p3/1999/g3-02203.pdf

Canada. 2005. Canadian Environmental Protection Act, 1999: New Substances Notification Regulations (Chemicals and Polymers). P.C. 2005-1484, 31 August 2005, SOR/2005-247. Canada Gazette, Part II, vol. 139, no. 19, p. 1864–1928. Available from: http://www.gazette.gc.ca/archives/p2/2005/2005-09-21/pdf/g2-13919.pdf

Canada, Dept. of the Environment, Dept. of Health. 2006. Guidelines for the Notification and Testing of New Substances: Chemicals and Polymers, Pursuant to Section 69 of the Canadian Environmental Protection Act, 1999––Version 2005 [cited 2011 Jun 2]. Available from: http://www.ec.gc.ca/subsnouvelles-newsubs/default.asp?lang=En&xml=FA59945E-8DD5-D745-8A55-EA6667737FE5

Canada, Dept. of the Environment. 2012. Canadian Environmental Protection Act, 1999: Notice with respect to certain substances on the Domestic Substances List. Canada Gazette, Part I, vol. 146, no. 48, Supplement, p. 2-94. Available from: http://www.gazette.gc.ca/rp-pr/p1/2012/2012-12-15/pdf/g1-14650.pdf

Canada, Dept. of the Environment, Dept. of Health. 2013. Final Screening Assessment of Substances of Low Concern. Available from: http://www.ec.gc.ca/ese-ees/2A7095CD-A88C-4E7E-B089-486086C4CBC4/RSI%20Final%20-%20EN.pdf

Canada, Dept. of the Environment, Dept. of Health. 2014. Rapid Screening Assessment of Substances from Phase One of the Domestic Substances List Inventory Update. Available from: http://www.ec.gc.ca/ese-ees/7340E1B7-1809-4564-8C49-F05875D511CB/FSAR_RSII_EN.pdf

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Appendix 1: Flowchart for the approach to address polymers

Appendix 2: List of candidate polymers on the DSL to be considered in the approach^{Footnote Appendix A Table A2 [a]}

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Appendix 3: List of masked substances to be considered in the approach