When I wrote the blog post on labelling hazardous household products, I was also planning to discuss the labelling of hazardous materials at the workplace. But as my post was already quite long, I opted not to write it. Then after seeing how much of a splash my article made, I finally decided to write this blog post about the main WHMIS symbols.

Unlike the labelling of hazardous household materials, which are subject to Canadian standards, the labelling of hazardous materials at the workplace is controlled by federal laws and an international classification and labeling system for chemicals: the Globally Harmonized System (GHS). Created in 2002, the GHS is gradually being integrated into the current Workplace Hazardous Materials Information System (WHMIS) in Canada.

Chemicals in the workplace

Legislation:    Requirements of the WHMIS (Canadian labelling standards) and the GHS (international classification)

The classification of chemicals and the pictograms that identify them, which is the topic of this blog post, are in accordance with the WHMIS.

While suppliers of hazardous household products incorporate the appropriate pictogram and mandatory text into the design of their label, the controlled products (as defined in the Hazardous Products Act) must be identified by a supplier’s label which must contain the following information about the product:

  • The name of the product
  • The symbol(s) indicating the hazard that the product represents
  • The risk phrases
  • Necessary precautions
  • First aid to administer
  • A reminder of the existence of a material safety data sheet, when applicable
  • The supplier’s name

Although employers must also follow the laws regarding controlled products, the suppliers are targeted here because they are responsible for labelling their merchandise.


For further information about legislation regarding the labelling of controlled chemicals at the workplace, I recommend consulting one of the following websites:

Controlled Products Regulations

WHMIS – Labelling Requirements

WHMIS – Workplace Hazardous Materials Information System – A passport to health and safety (in French only)