The Workplace Hazardous Materials Information System (WHMIS) requires that chemical suppliers provide employers with information on the hazards of materials produced or used in Canadian workplaces. This is accomplished through product labels and safety data sheets (SDSs) as specified in the Hazardous Products Regulations (HPR), or material safety data sheets (MSDSs) as specified in the now repealed Controlled Product Regulations. Employers may use this information when they prepare workplace (M)SDS and labels, and provide worker training.
A product's (M)SDS must fully disclose all hazardous ingredients in the product, its toxicological properties, any safety precautions workers need to take when using the product, and the first aid treatment required in the case of exposure.
When a supplier or employer wants to be exempt from having to disclose confidential business information (CBI), such as the chemical identity of one or more trade-secret hazardous ingredients, they must file a claim for exemption with Health Canada.
A Hazardous Materials Information Review Act Registry Number, issued by Health Canada, is required to be shown on the (M)SDS and for certain claims, on the label, for that product to be sold on the Canadian market without disclosure of the CBI.