Suppliers, employers and workers all have responsibilities in the Hazardous Products Act. Canadian suppliers are those who sell or import products. When this product is considered a “controlled product” according to the WHMIS legislation, a supplier must label the product or container, and it must provide a material safety data sheet (MSDS) to their customers. The purpose of the labels is to clearly identify the contents of the hazardous material, and the MSDS is to explain what those hazards are.