The Workplace Hazardous Materials Information System (WHMIS) is a Canada-wide system designed to give employers and workers information about hazardous materials used in the workplace. Under WHMIS, there are three ways in which information on hazardous materials is to be provided:

  1. labels on the containers of hazardous materials;
  2. material safety data sheets to supplement the label with detailed hazard and precautionary information; and
  3. worker education programs.

The supplier of the hazardous material provides the labels and material safety data sheets to the employer. The employer passes the information on to the worker and provides education programs.

WHMIS Classes – There are 6 Classes

The Controlled Products Regulations specifies the criteria used to place materials within each classification. There are six (6) classes although several classes have divisions or subdivisions. Each class has a specific symbol to help people identify the hazard quickly. The classes are:

  • Class A
    • Compressed Gas
  • Class B
    • Flammable and Combustible Material
      • Division 1 Flammable Gas
      • Division 2 Flammable Liquid
      • Division 3 Combustible Liquid
      • Division 4 Flammable solid
      • Division 5 Flammable Aerosol
      • Division 6 Reactive Flammable Material
  • Class C
    • Oxidizing Material
  • Class D
    • Poisonous and Infectious Material
      • Division 1 Materials causing immediate and serious toxic effects
        • Subdivision A Very toxic material
        • Subdivision B Toxic material
      • Division 2 Materials causing other toxic effects
        • Subdivision A Very toxic material
        • Subdivision Toxic material
      • Division 3 Biohazardous Infection Material
  • Class E
    • Corrosive material
  • Class F
    • Dangerously reactive material

The WHMIS Symbols

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Now take a quiz on WHMIS symbols