Employer obligations under WHMIS: a practical guide for Canadian organizations

Maintaining SDS libraries, ensuring proper labelling, delivering workplace-specific training, and keeping accurate records — a practical walkthrough of what WHMIS actually requires from Canadian employers.

WHMIS — the Workplace Hazardous Materials Information System — is Canada’s national system for communicating the hazards of chemicals used, stored, and handled in Canadian workplaces. It sets out what suppliers, employers, and workers each need to do to keep hazardous products identified, labelled, and understood. For employers, the obligations are specific, ongoing, and enforceable. This guide covers what they are in practice.

The three pillars every employer program rests on

WHMIS applies to any hazardous product used, stored, handled, or disposed of in a Canadian workplace, and it is built around three pillars: hazard classification, labelling, and Safety Data Sheets. Suppliers classify products, supply compliant labels, and provide an up-to-date SDS for each hazardous product they sell or import. Once those products enter your workplace, the responsibility shifts to you.

What employers must do

Employers who use hazardous products in the workplace must:

• Ensure all hazardous products are properly labelled
• Maintain an accessible, up-to-date SDS for every hazardous product on site
• Educate and train workers on the hazards of products they work with, and on how to read labels and SDS
• Establish workplace-specific procedures for safe handling, use, storage, and emergency response
• Review and update training and SDS on a regular basis

Each of these duties is continuous. A compliant SDS library in January can be non-compliant by June if suppliers issue updates that never reach your binder or database.

Who needs WHMIS training

Any worker who works with, handles, or may be exposed to a hazardous product in a Canadian workplace is required to receive WHMIS training. The scope is intentionally broad: “may be exposed” captures workers who are present where hazardous products are used, stored, or transported, even if they never personally handle them. That commonly includes maintenance staff, cleaners, administrative employees whose offices share a building with a laboratory or workshop, and supervisors who oversee work involving hazardous products.

In practice this reaches virtually every sector. In schools and universities it covers custodial and maintenance staff, science teachers and lab technicians, trades instructors, and facilities personnel — and students in programs such as chemistry labs, welding, or cosmetology typically require training before they begin. In healthcare, nurses, physicians, lab technicians, housekeeping, and facilities workers all work with or near cleaning and disinfecting agents, laboratory chemicals, pharmaceutical compounds, and sterilization materials. In municipalities, public works employees, transit maintenance workers, parks staff, water treatment operators, and building maintenance crews all regularly encounter hazardous products.

Temporary workers, contractors, and new employees all require WHMIS training before they begin working with hazardous products — and it is the employer on whose premises the work happens, not the staffing agency, who is responsible for ensuring everyone has received appropriate site-specific education.

Training must be workplace-specific

A generic online WHMIS course is not enough on its own. Employers are required to supplement general WHMIS education with training specific to the hazardous products actually present in that workplace, the procedures used to control exposure, and the emergency response measures in place. A worker who completed a general online course but has not received site-specific instruction has not fully satisfied the employer’s legal obligation. Keep records that document the content covered, the date, and the attendees.

Who enforces these obligations

WHMIS enforcement is divided between two levels of government. Health Canada enforces at the supplier level under the Hazardous Products Act and Hazardous Products Regulations, covering product classification, label content, and SDS compliance. Once a product enters a workplace, jurisdiction passes to the provincial or territorial occupational health and safety regulator — the Ministry of Labour under the OHSA in Ontario, WorkSafeBC in British Columbia, OHS officers under the OHS Act in Alberta, CNESST in Quebec, and equivalent bodies everywhere else. Federally regulated workplaces — banks, telecommunications, interprovincial transportation — fall under the Labour Program at Employment and Social Development Canada under the Canada Labour Code.

The result: a Canadian employer is accountable to two separate regulatory authorities — Health Canada for the products they purchase and their SDS, and their provincial OHS regulator for how they manage those products and train their workers.

Keeping your SDS library current

How often an SDS must be updated depends on your jurisdiction. Some provinces require an updated SDS within 90 days of significant new hazard information; others require employers to actively seek updated SDS every three years. Either way, when significant new data is released — such as the amendments covered in our WHMIS 2025 compliance update — every employer in every jurisdiction must obtain updated SDS reflecting those changes. Building supplier contact and SDS verification into an annual cycle remains the best practice regardless of where you operate.