Categorization of Substances on the Domestic Substances List

The first Canadian Environmental Protection Act, enacted in 1988, provided for an in-depth analysis of potential risks to human health and the environment posed by environmental contaminants through the assessment of substances on the Priority Substances List. Under this program, detailed health and environmental assessments were conducted on a total of 69 entries listed on the first (PSL1) and second (PSL2) Priority Substances Lists.

The revised Canadian Environmental Protection Act, 1999 (CEPA 1999) contains new provisions that allow for the faster assessment of a greater number of existing substances in Canada. This new process involves the categorization of the approximately 23 000 substances on the Domestic Substances List (DSL), which will be used to identify substances that will then undergo a screening assessment for potential risks to human health or the environment.

Under Section 73 of CEPA 1999, the Ministers of Health and of the Environment were to categorize the 23 000 substances on the DSL. Health Canada undertook to categorize substances on the DSL to identify those that pose the greatest potential for exposure of the general population in Canada (GPE) as well as those persistent or bioaccumulative substances considered "inherently toxic" to humans (IThuman). Environment Canada undertook to categorize substances on the DSL to identify those that are persistent or bioaccumulative and "inherently toxic" to non-human organisms.

Presented here are the results of the health-related categorization of the DSL under CEPA 1999 as well as associated documentation including:

• Lists of substances from the DSL considered to represent either a high, moderate or low health priority for further action.
• An accompanying document that summarizes the mandate, approaches adopted, results and next steps associated with the health-related components of DSL categorization.
• A list of frequently asked questions and answers related to the health-related components of DSL categorization.

The proposal (Categorization of the Domestic Substances List (DSL) for Greatest Potential for Human Exposure) for priority setting related to Health Canada's mandate to categorize substances on the DSL for greatest potential for human exposure (GPE) was previously made available for public comment