Domestic Substances List
Categorization and Screening Program

One of the new initiatives in the Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the Minister of the Environment and the Minister of Health to “categorize” (Section 73, CEPA 1999) and then if necessary, conduct screening assessments (Section 74, CEPA 1999) of substances listed on the Domestic Substances List (DSL) to determine whether they are “toxic” or capable of becoming “toxic” as defined in the Act. Under the Act, a substance is “toxic” if it is entering or may enter the environment in a quantity or concentration or under conditions that;

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

The DSL includes substances that were, between January 1, 1984, and December 31, 1986, in Canadian commerce, used for manufacturing purposes, or manufactured in or imported into Canada in a quantity of 100 kg or more in any calendar year. The purpose of the List was to define what was 'New to Canada' and it has been amended from time to time following assessment under the New Substances Notification Regulations and currently contains approximately 23,000 substances. Types of substances on the DSL include simple organic chemicals, pigments, organometallic compounds, surfactants, polymers, metal elements, metal salts and other inorganic substances, products of biotechnology as well as substances that are of “Unknown or Variable Composition, complex reaction products, or Biological materials” (referred to as UVCBs). Although "new substances" are also included on the DSL only those substances which have not or will not be evaluated as a new substance will be examined under the DSL Categorization and Screening exercise.