Domestic substances list: categorization of existing substances
Since 1994, Canada has been screening all new chemical substances before allowing their use. However, many chemical substances were introduced prior to 1994. Many of these older, or "existing substances" had not been examined for their potential risks by environmental and health scientists in government. Approximately 23 000 existing substances are registered on the domestic substances list (DSL).
The Canadian Environmental Protection Act, 1999 (CEPA) requires that existing substances be sorted or "categorized" by the Government of Canada to determine which need further attention. Categorization is the first step in scientifically assessing all chemical substances on the DSL.
Using information from Canadian industry, academic research and other countries, Government of Canada scientists at Health Canada and Environment and Climate Change Canada worked with partners in applying a set of rigorous tools to each of the approximately 23 000 chemical substances on the DSL. In September 2006, Canada completed this scientific evaluation or "categorization" exercise. The information from categorization is now available and is being used to focus attention on those chemical substances of highest priority for assessment or further research, and those in need of controls to protect human health and the environment.