Across Canadian workplaces, the Workplace Hazardous Materials Information System (WHMIS) is the national standard for classifying, labelling, and providing safety information about hazardous products. It works through three key components: labels that display hazard symbols and precautionary measures, Safety Data Sheets (SDSs) that provide detailed handling and health information, and worker training to ensure employees know how to recognize and safely manage hazardous materials. Together, these components give workers the knowledge and tools they need to protect themselves from chemical hazards on the job.
Why WHMIS 2025 Is Important
Amendments to the Hazardous Products Regulations (HPR) came into force on December 15, 2022, with a 3-year transition period ending December 14, 2025. The changes align Canada’s system with the most recent Globally Harmonized System (GHS) and are meant to improve hazard communication.
Benefits of WHMIS 2025 include:
- More comprehensive hazard information on labels and SDSs.
- Increased clarity and precision in hazard communication.
- Stronger alignment with global standards.
- Better worker protection through accurate and detailed safety instructions.
What’s New in WHMIS 2025
New Hazard Classes
- Flammable gases are now split into two groups: Category 1A for pyrophoric/unstable gases and Category 1B
- Aerosols now include a new group for non-flammable aerosols.
- Chemicals Under Pressure is a brand-new hazard class.
Changes to Safety Data Sheets
- More details are now required, such as the physical state, vapour density, and particle size.
- All hazardous ingredients above cut-off levels must be listed, even if they don’t affect classification.
- New requirement to state if a product releases toxic gas when it contacts water.
Hazard Statements
- Combustible dust products now allow a second option:
- “May form combustible dust concentrations in air,” OR “May form explosible dust-air mixture.”
Documentation of Changes
- Suppliers must now record and date any significant updates made to SDSs or labels.
WHMIS 2015 vs. WHMIS 2025
While WHMIS 2025 builds on WHMIS 2015, there are several notable differences.
Flammable gases, aerosols, and chemicals under pressure have been redefined or added to reflect international best practices. SDSs now require far more detailed physical and chemical data, and ingredient disclosure rules have become stricter. Finally, documentation of SDS and label updates is now mandatory, meaning that every significant change must be recorded and dated.
Employer Responsibilities
Employers must:
- Ensure all workplace products are compliant with WHMIS 2025 by December 14, 2025
- Update SDSs and labels as required.
- Provide workers with updated WHMIS training that covers new hazard classes and categories.
Key Takeaway
WHMIS 2025 is not an entirely new system but a significant and mandatory evolution of WHMIS 2015. By December 14, 2025, all workplaces in Canada must be fully compliant. These updates sharpen hazard communication, expand SDS content, introduce new physical hazard classes, and require better documentation. For employers and workers alike, the end goal is safer workplaces and clearer, more reliable information about the materials we handle every day.
Your Kasa Consulting advisor can help you get there by reviewing your current program, updating SDSs and labels, assisting with supplier communications, and delivering updated worker training. Reach out today to make sure your workplace is ready ahead of the deadline.