WHMIS 2025 compliance update: what every Canadian employer must do now

The December 2022 amendments to the Hazardous Products Regulations are now fully in force. Here is what changed, why the December 14, 2025 deadline matters, and the five actions every Canadian employer must take.

WHMIS has evolved steadily 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 recently, you are likely operating with compliance gaps that expose your workers and your organization to enforcement risk.

How we got here: from WHMIS 1988 to WHMIS 2015

When WHMIS first became law in 1988, 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 today: hazardous product labels, safety documentation, and worker education and training.

In 2015, Canada aligned WHMIS with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), the UN framework for standardizing chemical hazard communication worldwide. The changes were formalized through amendments to the Hazardous Products Act and the new Hazardous Products Regulations (HPR) published in February 2015. Material Safety Data Sheets became the mandatory 16-section Safety Data Sheet, the old lettered classes gave way to GHS hazard classes with numbered severity categories, and the familiar red diamond pictograms replaced Canada’s hatched-border symbols. Suppliers had until June 1, 2017, and employers had until December 1, 2018, to replace all MSDS with compliant SDS.

What changed on December 15, 2022

On December 15, 2022, Health Canada amended the Hazardous Products Act and the HPR 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 on December 14, 2025. All hazardous products in Canadian workplaces must now meet the amended requirements.

The amendments affected four main areas:

• New hazard class: Chemicals Under Pressure. Covers liquefied and dissolved gases under pressure in non-cylinder containers, displaying both the Flame and Gas Cylinder pictograms together.
• Aerosols class renamed and expanded. “Flammable Aerosols” became “Aerosols,” with a new Category 3 for non-flammable aerosols that requires labelling but no pictogram.
• Flammable Gases reclassified. Category 1 was split into 1A (pyrophoric and chemically unstable gases) and 1B, with Category 1A carrying higher hazard communication requirements.
• SDS content expanded. Section 9 now requires additional data — melting point, pH, solubility, vapour pressure, and particle characteristics — and Section 14 requires more detailed transport entries. Ingredient disclosure was also tightened: all hazardous ingredients above cut-off levels must now be listed, even if they do not contribute to the product’s overall classification.

The compliance picture after December 14, 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. You cannot assume an older SDS remains current — every document needs to be verified against the amended HPR.

What employers must do now

These are legally required actions, not optional improvements.

1. 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.
2. Request updated SDS from suppliers. Suppliers must provide compliant SDS at time of sale. Depending on your jurisdiction, you must either actively seek updates every three years or obtain them within 90 days of significant new information — see our province-by-province SDS compliance guide for where you fall.
3. Update workplace labels. Secondary containers, decanted products, and in-house labelled materials must reflect the new Chemicals Under Pressure class and the revised Aerosols categories. Mislabelled secondary containers are the most frequently cited OHS inspection finding.
4. 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 the content covered, the date, and the attendees.
5. Update your written WHMIS program. Review all procedures for SDS procurement, workplace labelling, and training delivery to confirm they reference the amended HPR. Our guide to employer obligations under WHMIS walks through the full set of duties.

The bottom line

WHMIS will continue to evolve as the UN updates the GHS framework, but 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.