Approach and results for the prioritization of substances on the Revised In Commerce List

Health Canada developed an approach to prioritize substances on the Revised In Commerce List (R-ICL). This approach was intended to be protective and risk-based, as well as expedient and pragmatic. Available information on hazard and exposure was considered together  to identify substances that were lower or higher priority. The prioritization approach used recommendations received during multi-stakeholder consultations that took place between 2007 and 2011, experience gained during the categorization of the Domestic Substances List (DSL) and subsequent evaluation of priorities, and experience from assessments conducted on new substances notified under the New Substances Notification Regulations (NSNR) (Chemicals and Polymers), or NSNR (Organisms), of the Canadian Environmental Protection Act, 1999 (CEPA). As of 2016, the prioritization process had been applied to approximately 3,500 R-ICL substances, based on information available at the time

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The prioritization approach

1. Substances previously reviewed

The first step of the prioritization process was to identify those substances on the R-ICL that were also on the DSL, and had either undergone categorization, or else were added to the DSL following notification and assessment under the NSNR as part of the New Substances program, which is jointly administered by Health Canada and Environment and Climate Change Canada. Since these substances had already undergone a review for their potential risk to human health or to the environment, they were not considered further in the R-ICL prioritization process.

Substances on the R-ICL that had been notified under the NSNR but not yet added to the DSL were given lower priority in the context of the R-ICL when the toxicological characteristics, quantities and uses in products regulated under the Food and Drugs Act (F&DA) were thought to be comparable to those evaluated during assessment under NSNR and deemed to be of low concern. Conversely, assessments under NSNR , which identified toxicological or ecotoxicological concerns were used to support a decision for higher priority consideration.

2. Substances with certain high health or environmental hazard considerations

The second step of the prioritization process was to identify substances having certain indications of high health or environmental hazard.

Substances associated with hazard flags generally required further evaluation to determine whether they posed a significant risk to human health or the environment when their use patterns and environmental exposure were taken into consideration. These included substances identified:

  • as hazardous by national or international agencies
  • in product monographs as carcinogenic, genotoxic or toxic to reproduction
  • as endocrine disrupters
  • as persistent organic pollutants

If reliable information on current and anticipated use patterns and quantities mitigated these hazards such that the substance was unlikely to pose a significant risk to human health or the environment, the substance was identified as a lower priority.

3. Substances from natural sources

This next step involved a qualitative review of substances considered to be from natural sources. Types of substances in this group included:

  • natural biopolymers
  • plant extracts
  • mineral extracts
  • proteins
  • fats
  • animal extracts
  • waxes
  • carbohydrates

Also included were certain derivatives of these substances (for example, hydrolysates). Examples of products utilizing these substances range from food products, to cosmetics, to natural health products. Expert judgement in chemistry, toxicology and ecotoxicology was applied to identify substances that were considered unlikely to be persistent or bioaccumulative, or to have significant health or environmental impacts resulting from its use as a product regulated under the F&DA. These substances were identified as lower priority in the R-ICL prioritization process.

4. Potential exposure and use patterns

Exposure is a key factor determining the potential of a substance to harm human health or the environment, and, as such can be used as a rapid screening flag to identify substances as higher or lower priority. Health Canada used available information on the quantities and use patterns of a substance to characterize potential exposure of the general population and release to the environment. During this analysis, consideration was also given to whether the quantities and use pattern were likely to change in the future. If potential exposure was considered to be negligible and the substance was unlikely to cause harm to human health or the environment, then the substance was identified as lower priority. For example, substances no longer in commerce, or known to be in commerce only in limited quantities, and/or with limited defined use patterns, were identified as lower priority in the R-ICL prioritization process.

If the potential for environmental release or exposure of the general population was considered to be high, then further consideration, particularly regarding potential toxicological hazards, environmental fate, and use pattern, was required to more fully assess the impact of the substance on human health or the environment. Substances in commerce at high quantities, or whose use pattern is likely to result in significant releases to the environment, were generally considered higher priority.

5. Substance groupings

In order to be both comprehensive and pragmatic, prioritization involved identifying groups of substances that could be reviewed together. Substances were grouped based on similar chemical structure, or in the case of micro-organisms, their taxonomical classification, and/or use pattern. Examples of groupings based on chemical structure include quaternary ammonium compounds, alcohol ethoxylates, and substances that contain certain metals. Examples of groupings based on use pattern include pharmaceuticals with similar mechanism of action, or substances used as fragrances. Grouping substances together enabled more efficient information-gathering, and a consistent handling of substances within a group.

6. Remaining substances

For substances that did not obviously fit within any grouping, substance-specific information regarding the properties, toxicity, ecotoxicity, use pattern, quantities, and releases was gathered, and/or modelled and used to inform a prioritization decision. Search criteria for information gathering on these substances was standardized to ensure that there was a systematic approach to research and consistent effort was applied. This information was used in a weight of evidence and precautionary manner to determine whether the substance required higher priority consideration.

Prioritization results

Health Canada applied this prioritization approach to the approximately 3,500 R-ICL substances as of 2016. As a result, the R-ICL list was separated into 2 broad categories: “higher priority”, or “lower priority”. Substances in the “higher priority” category were identified for some form of follow-up, for example, information gathering activities or risk assessment, to ultimately determine whether these substances pose risks to the environment or human health. Substances in the “lower priority” category were of reduced priority, at least in the context of the R-ICL, such that no immediate follow-up activity was identified at the time prioritization was conducted.

R-ICL prioritization decisions were based on available information found for the substance, including criteria suggesting low risk or because there was no evidence raising concern. These decisions, whether they were related to potential concerns to human health, the environment, or both, were based on preliminary information.

Results from the prioritization of the R-ICL are shown on the R-ICL tracking table.

The results of this prioritization exercise, along with other available information on R-ICL substances, have since been taken into consideration during the identification and selection of assessment priorities for the proposed Plan of Priorities under CEPA.

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