Hazard Classifications (Classes and Categories)

When a material is listed as a hazardous product, the manufacturer must treat the product according to WHMIS regulations. Part of this regulation is to classify it according to a hazard class.

WHMIS 2015 has many hazard classes. The class describes the different types of hazards. For example, Flammable Solids is a hazard class. Each hazard class is further split into categories or subcategories (Types A, B, C, D, E and F). For example, Category 1 is always more hazardous than Category 2 or 3.

The hazard class and category are a guide to the:

  1. Type of hazard
  2. Degree of hazard
  3. Precautions to follow

Gasoline is a Flammable Liquid – Category 2, can easily catch fire, and as a precaution you should keep away from heat, hot surfaces, sparks, etc.


Note: Some products present more than one hazard and can belong to more than one hazard class.

Stop and Think Activity:

What hazards are in your work area?