Under the Canadian Hazardous Products Act, a chemical must be listed in the Hazardous Ingredients Section of a Material Safety Data Sheet (MSDS) if: 1.it meets the criteria for a controlled product; 2.it is on the Ingredient Disclosure List; 3.there is no toxicological information available; or 4.the supplier has reason to believe it might be hazardous. | Certain chemicals may be exempt from disclosure on an MSDS if they meet specific criteria set out in the Hazardous Materials Information Review Act. These Acts are part of the Workplace Hazardous Materials Information System (WHMIS).