A brief history of WHMIS and what your organization must do now that the December 2025 amendments are in force.
WHMIS has evolved since it was introduced as law in 1988 — and the most recent set of changes came into full legal force on December 15, 2025. If your organization has not reviewed its Safety Data Sheet library, its workplace labels, and its WHMIS training program in a while, you are likely operating with compliance gaps that expose your workers and your organization to enforcement risk.
This article offers a brief history of WHMIS and the steps a Canadian employer must take to maintain a compliant WHMIS program today.
Where it Started: WHMIS 1988
When WHMIS first became law in 1988, it was genuinely groundbreaking. Canada became one of the first countries in the world to establish a national framework requiring employers to communicate hazard information about workplace chemicals to the workers who handled them. The system operated through three pillars that remain central to WHMIS today: hazardous product labels, Material Safety Data Sheets (MSDS), and worker education and training.
The system worked reasonably well for nearly three decades. With increased global trade workers handling the same chemical in different countries were reading different labels with different symbols. Emergency responders crossing international borders encountered unfamiliar hazard communication formats. The case for global harmonization was compelling.
The First Major Overhaul: WHMIS 2015
In 2015, Canada aligned WHMIS with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), a UN framework for standardizing chemical hazard communication worldwide. The changes, formalized through amendments to the Hazardous Products Act and the new Hazardous Products Regulations published in February 2015, touched every component of the system.
| Component | WHMIS 1988 | WHMIS 2015 |
|---|---|---|
| Hazard symbols | Black symbols inside a hatched border, unique to Canada | GHS red diamond pictograms used internationally. Canada retained the circular biohazard symbol |
| Safety documentation | Material Safety Data Sheet (MSDS) — no standard format, structure varied by supplier | Safety Data Sheet (SDS) — mandatory 16-section format, uniform across all GHS-adopting countries |
| Classification system | Broad classes identified by letter (Class A through F) | GHS hazard classes with numbered severity categories (e.g., Flammable Liquid Category 1, 2, 3, or 4) |
| Regulatory basis | Controlled Products Regulations | Hazardous Products Regulations (HPR) |
| Terminology | 'Controlled products,' 'MSDS' | 'Hazardous products,' 'SDS' |
The transition was phased: suppliers had until June 1, 2017, and employers had until December 1, 2018 to replace all MSDS with compliant SDS. Any organization still holding MSDS documents after that date was non-compliant. WHMIS 2015 became the national standard.
WHMIS Evolves: Current Standard Update In Dec 2022
On December 15, 2022, Health Canada amended the Hazardous Products Act and Hazardous Products Regulations to align Canada with GHS Revisions 7 and 8. Suppliers had a three-year transition period to update their product classifications, labels, and SDS. That window closed December 14, 2025. All hazardous products in Canadian workplaces must now meet the amended requirements.
The amendments affected four areas:
| What changed | Details |
|---|---|
| New hazard class: Chemicals Under Pressure | Covers liquefied and dissolved gases under pressure in non-cylinder containers. Displays both the Flame and Gas Cylinder pictograms together |
| Aerosols class renamed and expanded | 'Flammable Aerosols' became 'Aerosols.' A new Category 3 for non-flammable aerosols was added. Category 3 requires labelling but no pictogram |
| Flammable Gases reclassified | Category 1 split into 1A (pyrophoric and chemically unstable gases) and 1B. Category 1A carries higher hazard communication requirements |
| SDS content expanded | Section 9 now requires additional data: melting point, pH, solubility, vapour pressure, and particle characteristics. Section 14 requires more detailed transport entries |
| Ingredient disclosure tightened | All hazardous ingredients above cut-off levels must now be listed, even if they do not contribute to the product's overall classification |
Employers cannot assume an older SDS remains current — every document in the library needs to be verified against the amended HPR.
The Compliance Picture Post-December 2025
The transition period is over. Non-compliant SDS or labels are now treated as violations under the Hazardous Products Act. One point employers often miss: if a supplier failed to update their SDS by December 14, 2025, the employer is still responsible for replacing that non-compliant document in their workplace library.
What Employers Must Do Now
These are legally required actions — not optional improvements.
| Action | What it means |
|---|---|
| Audit your SDS library | Check every SDS for compliance with the amended HPR, paying particular attention to Sections 9 and 14. Replace any document still formatted to WHMIS 2015 |
| Request updated SDS from suppliers | Suppliers must provide compliant SDS at time of sale. BC, Saskatchewan, and federally regulated employers must seek updates every three years. Alberta, Ontario, and Quebec employers must obtain updates within 90 days |
| Update workplace labels | Secondary containers, decanted products, and in-house labelled materials must reflect the new Chemicals Under Pressure class and revised Aerosols categories. Mislabelled secondary containers are the most frequently cited OHS inspection finding |
| Retrain workers | Any worker trained only on WHMIS 2015 has not been trained on Chemicals Under Pressure or Category 3 Aerosols. Training records must document content covered, date, and attendees |
| Update your written WHMIS program | Review all procedures for SDS procurement, workplace labelling, and training delivery to confirm they reference the amended HPR |
The Bottom Line
WHMIS will continue to evolve as the UN updates the GHS framework. The December 2022 amendments are now fully in force and represent the most significant update to the Canadian system in a decade. If your SDS library, workplace labels, and worker training have not been reviewed against the amended HPR, the time to act is now — before an OHS inspection makes the decision for you.
CanadaSDS is Canada's purpose-built SDS management platform, designed to keep municipalities, school boards, healthcare organizations, and post-secondary institutions compliant across every provincial jurisdiction. Learn how CanadaSDS manages SDS compliance for your organization.
