WHMIS Symbols and Their Meanings

Flame

Flammable products: they can catch fire easily, or give off flammable gas.

Flame over circle

Oxidizers: they can cause or worsen a fire.

Exploding bomb

Explosion or reactivity hazard: some self-reactive products and organic peroxides.

Gas cylinder

Gases under pressure: the container may explode if heated.

Corrosion

Corrodes metal, or causes severe skin burns and eye damage.

Skull and crossbones

Acute toxicity: can be fatal or toxic even in small amounts.

Exclamation mark

Less severe health effects: irritation, allergic skin reaction, dizziness.

Health hazard

Serious long-term effects: cancer, organ damage, breathing sensitization.

Biohazardous infectious materials

Organisms or toxins that can cause disease (WHMIS only).

Want it on the wall? Download our free printable WHMIS symbols poster, then test yourself with the WHMIS symbols quiz.

Flame

The flame means a fire hazard. It covers flammable gases, aerosols, liquids and solids, pyrophoric products (they catch fire on contact with air), self-heating products, products that give off flammable gas in contact with water, and some self-reactive products and organic peroxides. Keep these away from heat, sparks and open flames, and store them as the label and SDS say.

Flame over circle

The flame over a circle means an oxidizer. Oxidizing gases, liquids and solids give off oxygen, so they can start a fire or make one burn hotter and faster. Never store them next to flammable or combustible materials.

Gas cylinder

The gas cylinder means gases under pressure: compressed, liquefied, refrigerated liquefied or dissolved gases. The container can burst if it is heated or damaged, and refrigerated gases can cause cold burns. Secure cylinders upright and keep them away from heat.

Corrosion

The corrosion symbol shows liquid eating into a hand and a metal bar. It means the product can cause severe skin burns and eye damage, or is corrosive to metals. Wear the gloves, goggles or face shield the SDS lists, and know where the eyewash station is.

Exploding bomb

The exploding bomb means an explosion or reactivity hazard. In WHMIS it is used for the most reactive self-reactive substances and organic peroxides, which can explode if heated, shocked or contaminated. (Explosives themselves are regulated under the Explosives Act, not WHMIS.)

Skull and crossbones

The skull and crossbones means acute toxicity: the product can be fatal or toxic after a single short exposure, by swallowing, skin contact or breathing it in. Follow the label exactly, and know the first-aid steps in section 4 of the SDS before you use it.

Health hazard

The health hazard symbol (a person with a star on the chest) means serious or long-term health effects. It covers products that may cause cancer, genetic damage, harm to fertility or an unborn child, organ damage, breathing sensitization (asthma-like reactions), or lung damage if swallowed and then inhaled (aspiration hazard). The harm can show up years later, so use the PPE and controls every time.

Exclamation mark

The exclamation mark means less severe health effects: skin or eye irritation, skin allergies, being harmful if swallowed or inhaled, or breathing irritation, drowsiness or dizziness. "Less severe" does not mean safe. Read the label and avoid repeated contact.

Biohazardous infectious materials

This symbol is unique to WHMIS (it is not a GHS symbol). It is drawn inside a black circle instead of a red diamond, and it marks micro-organisms, nucleic acids or proteins that can cause disease in people or animals, such as some lab cultures. Workers who handle these need specific procedures, PPE and often bloodborne pathogens training.

A few hazard classes have no symbol at all, for example combustible dusts and simple asphyxiants. Their labels use a signal word ("Danger" or "Warning") and hazard statements instead, which is why reading the whole label matters.

No. You will often read that there are "10 WHMIS symbols" because the global GHS system also has an environment pictogram (a dead tree and fish). Environmental hazards are not part of WHMIS, so that symbol is not required on Canadian workplace labels, but you may still see it on products sold internationally. For WHMIS, learn the 9 symbols above.

Before WHMIS 2015, Canada used 8 symbols inside a circle on labels with a hatched border (WHMIS 1988). WHMIS 2015 replaced them with the red-diamond GHS pictograms, and the changeover ended for most workplaces on December 1, 2018. If you still find a product with an old circle symbol, ask your supervisor: it should have a current WHMIS 2015 label and SDS.

In December 2022 Health Canada also amended the Hazardous Products Regulations (for example, adding a "chemicals under pressure" hazard class), with a transition for suppliers that ended in December 2025. The 9 pictograms did not change.

WHMIS symbols are for products in the workplace. When dangerous goods are shipped, they use Transportation of Dangerous Goods (TDG) labels and placards instead: coloured diamonds with a class number at the bottom (for example, red with a "3" for flammable liquids). Some symbols look alike, but the systems have different rules. If you handle, ship or receive dangerous goods, you need TDG training as well as WHMIS.

• Supplier labels: on the product as it arrives, with the pictograms, signal word, hazard and precautionary statements, and the supplier’s details.
• Workplace labels: when a product is moved into another container or made on site. They must show the product name, safe-handling information and a reference to the SDS. Pictograms are often included.
• Safety Data Sheets: section 2 (hazard identification) shows the same pictograms as the label. Read our guide to the 16 SDS sections.

Yes. Every province requires employers to train workers who work with or near hazardous products: in British Columbia under Part 5 of the OHS Regulation, in Ontario under Regulation 860, and in Alberta under Part 29 of the OHS Code. Training has two parts: general WHMIS education (symbols, labels and SDSs) and site-specific training on the products at your workplace. Many provinces, including B.C. and Ontario, also require employers to review WHMIS training at least once a year.

Not sure if your training is still current? See how long WHMIS is good for. Want the full list of hazard types behind the symbols? See WHMIS hazard classes.

Our online WHMIS course covers the general part in about 90 minutes, in several languages, with unlimited free exam retakes and an instant certificate.