WHMIS 2025: What Changed and What It Means for Your Workplace

"WHMIS 2025" is the name for WHMIS after Canada's 2022 update to the Hazardous Products Regulations, whose three-year transition ended on December 14, 2025. Most of the changes fall on suppliers: a new hazard class, renamed aerosol classes and more detail on safety data sheets. Employers' duties stay the same, but workers now see updated labels and SDSs, so older training may need a refresh.

"WHMIS 2025" is the name for WHMIS after Canada's 2022 update to the Hazardous Products Regulations. The update came into force on December 15, 2022, and suppliers had until December 14, 2025 to bring their labels and safety data sheets (SDSs) in line. Most of the changes land on suppliers. Your duties as an employer haven't changed, but your workers are now seeing new labels and SDS wording, so it's a good time to refresh their training.

Key facts about WHMIS 2025

• What it is: WHMIS (the Workplace Hazardous Materials Information System) is Canada's system for sharing information about hazardous products at work. It lines up with the international Globally Harmonized System (GHS).
• What changed: the federal Hazardous Products Regulations were amended to align with GHS Revision 7 and parts of Revision 8.
• Key dates: published in the Canada Gazette, Part II, on January 4, 2023. In force since December 15, 2022. The three-year transition ended December 14, 2025.
• Who it affects most: suppliers, meaning the companies that make, import or sell hazardous products. They classify products and write labels and SDSs.
• What employers still do: keep labels on products, keep current SDSs where workers can get them, and train workers. In Alberta that's Part 29 of the OHS Code.
• Enforcement: Health Canada says it will focus on compliance promotion until July 19, 2027, then move to its usual risk-based approach.
• Training: the law doesn't set a fixed renewal date. Workplace training has to match the products and information your workers actually see.

What is WHMIS?

WHMIS is how Canadian workplaces communicate chemical and product hazards. It has three main parts: labels on containers, safety data sheets with the detailed information, and worker education and training. Behind all three is hazard classification, where the supplier decides which hazard classes and categories a product falls into.

WHMIS sits on two levels of law. The federal Hazardous Products Act and Hazardous Products Regulations tell suppliers how to classify products and what goes on labels and SDSs. Provincial and territorial OHS laws tell employers what to do at the work site. In Alberta, that's Part 29 of the Occupational Health and Safety Code.

Canada's system is based on the GHS, a United Nations system used around the world. The GHS is revised every so often. When Canada catches up to a new revision, the WHMIS rules change, and training providers usually put the new year in their course names. That's where names like WHMIS 2015 and WHMIS 2025 come from. They aren't separate laws. They're the same system at different points in time.

What changed in WHMIS in 2025?

The changes came from amendments to the Hazardous Products Regulations. They were published in the Canada Gazette, Part II, on January 4, 2023, and came into force on December 15, 2022. They align Canada with the 7th revised edition of the GHS and parts of the 8th. The year 2025 is when the transition ended, which is why the updated system is often called WHMIS 2025.

Hazard class changes

• New class: Chemicals Under Pressure. It is a new physical hazard class.
• Aerosols: the "Flammable Aerosols" class is now just "Aerosols". It has a new Category 3 for non-flammable aerosol products.
• Flammable Gases: Category 1 now has subcategories.
• Pyrophoric Gases: this class was repealed. Those gases are now classified under Flammable Gases, Category 1A.

Safety data sheet changes

• Every hazardous ingredient in a mixture above the cut-off level must be listed, even if it doesn't change how the mixture is classified.
• New information is required in the physical and chemical properties section.
• A combustible dust hazard can now use the alternative statement "May form explosible dust-air mixture".
• Suppliers must document label and SDS changes they make because of significant new data.

Confidential business information

When a supplier keeps an ingredient's exact concentration confidential, it can show a range instead. The amendments let suppliers use narrower ranges within the set bands. Workers get a closer idea of what's in the product.

When did the WHMIS transition end?

The transition ended on December 14, 2025. Health Canada gave everyone three years from December 15, 2022 to move from the old rules to the new ones. During that time, a supplier could follow either the old or the new requirements.

Health Canada has also said it will focus on compliance promotion until July 19, 2027. That date matches the United States deadline for mixtures under its own update. After that, it plans to follow its usual risk-based approach to compliance and enforcement. That's about how the federal government deals with suppliers. It doesn't change what your provincial OHS law asks of you as an employer.

In practice, you'll see old-format and new-format labels side by side for a while. Products bought before the change can still be on your shelves. That mix is exactly why workers need to be able to read both.

Is WHMIS training mandatory in Alberta?

Yes. Section 397 of the Alberta OHS Code says an employer must make sure a worker who works with or near a hazardous product is trained. The training has to cover:

• What goes on a supplier label and a work site label, and what that information means
• What goes on a safety data sheet, and what that information means
• How to safely store, use and handle the hazardous products
• How to safely manufacture the product, if your workers do that
• Other ways products are identified at your site, if you use them
• What to do about fugitive emissions, meaning leaks or escapes
• What to do in an emergency involving the product

The employer has to develop and put these procedures in place with the joint health and safety committee or the health and safety representative, if there is one. The Code also says every hazardous product or its container needs a supplier label or a work site label (section 398). You must also keep the SDS current and readily available to workers who may be exposed (sections 406 and 407).

Do I need new WHMIS training for 2025?

No law says every worker must retake WHMIS because of the 2022 amendments. But the law does say training has to cover the labels and SDSs your workers actually use. Those labels and SDSs now use the updated classes and wording. If your workers last took WHMIS several years ago, they may not recognize a Chemicals Under Pressure hazard or an "Aerosols, Category 3" label.

CCOHS, the Canadian Centre for Occupational Health and Safety, lists the times refresher training is needed. They include when conditions in the workplace change, when new products come in, and when new hazard information becomes available. New supplier labels and SDSs fit that last one. A short refresher that uses the current system is the simplest way to close the gap.

It also helps at audit time. When an auditor interviews your workers, they may ask what a pictogram means or where to find an SDS. Workers who trained on the current system answer with confidence.

How often is WHMIS training required?

Alberta's OHS Code doesn't set a fixed renewal period, and CCOHS notes that most Canadian jurisdictions don't either. Instead, CCOHS recommends that employers review their WHMIS education and training program at least once a year. Review it sooner if work conditions, processes or hazard information change.

So the real answer is: as often as it takes for workers to stay current. Many companies set their own refresher cycle so it doesn't slip. The certificate from our WHMIS 2025 course carries a 36-month validity date. That date is a reminder to refresh, not a limit set by Alberta law. Your own program can call for more frequent training.

Retrain right away, without waiting for a date, when:

• A new hazardous product arrives on site
• A process changes the way a product is used or stored
• A supplier sends significant new hazard information
• A worker can't explain a label or find an SDS
• An incident or near miss involves a hazardous product

What's the difference between WHMIS education and training?

CCOHS splits it in two. Education is the general, portable part: how WHMIS works, the hazard classes, and how to read labels and SDSs. Training is the site-specific part: your products, your procedures and your emergency plans.

The general part moves with the worker. If someone changes employers, they may not need to redo it. The site-specific part never moves. Every employer has to train workers on the products and procedures at their own site.

A good setup uses both. Workers take an online WHMIS 2025 course for the general part. Then a supervisor walks them through the products they'll handle, where the SDSs are kept, and what to do in a spill or exposure. Keep a record of both.

What should employers do now?

1. Check your SDSs. Make sure each one is the current version from the supplier. If a supplier sends significant new data, Alberta's Code gives you no more than 90 days to update the SDS.
2. Walk your storage areas. Look for missing or damaged labels, and for decanted products that need a work site label.
3. Refresh your workers' general WHMIS education so it covers the current hazard classes.
4. Update your site-specific training for any new products or changed procedures.
5. Review your WHMIS program. Once a year is the CCOHS recommendation, and sooner if things change.
6. Keep records of who was trained, on what, and when. Your COR auditor will ask for them.

How WHMIS fits your COR audit

In a COR audit, WHMIS usually shows up in a few places. Auditors look at your training records, your hazard assessments for work with chemicals, and whether SDSs are current and easy to find. They'll also ask workers about it in interviews.

Gaps tend to be simple: an SDS binder that's years out of date, a new hire with no WHMIS record, or a decanted jug with no label. They're easy to fix before the audit and costly to find during it.

Related training

• WHMIS 2025 online course
• Spill Response
• Transportation of Dangerous Goods (TDG)
• All online safety courses