Assessment of substances under the Canadian Environmental Protection Act, 1999

The Canadian Environmental Protection Act, 1999 (CEPA) respects pollution prevention and the protection of the environment and human health in order to contribute to sustainable development. Under CEPA, the federal Ministers of the Environment and of Health are required to identify and determine which existing substances already in the environment pose a risk to human health or to the environment. (The Domestic Substances List (DSL) is the sole standard against which a substance is judged to be "new" to Canada.)

CEPA specifies a number of ways in which existing substances can be identified for assessment. These are:

• categorization of substances on the Domestic Substances List (Section 73);
• review of decisions of other jurisdictions (Section 75); and
• addition to the Priority Substances List (Section 76).

In determining whether a substance is "toxic" under CEPA, the likelihood and magnitude of releases into the environment and the harm it may cause to human health or ecosystems are taken into account. CEPA provides the framework for the identification, prioritization and assessment of existing substances and for the control or management of those considered to pose a risk. This framework is broad, open, transparent and evidence-based.