Priority Substances Assessment Program

The Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the establishment of a Priority Substances List (PSL). Substances on this List are of priority for assessment to determine whether environmental exposure to them poses a risk to the health of Canadians or to the environment. A Priority Substance may be a chemical, a group of chemicals, effluents or wastes. There have been two PSLs; PSL1 (see First Priority Substances List Assessments) and PSL2 (see Second Priority Substances List Assessments), which were established by the Ministers of Health and of the Environment, based on the recommendations of a Ministers' Expert Advisory Panel.

The responsibility for assessing Priority Substances is shared by Health Canada and Environment Canada. Health Canada assesses the risks to human health from environmental exposure to Priority Substances. Environment Canada assesses the risks to the environment and non-human organisms.

For further information on assessing the risks to human health of Priority Substances, see Assessing and Managing the Health Risks of Existing Substances under the renewed Canadian Environmental Protection Act, 1999 (CEPA 1999).