WHMIS Hazard Classes and Pictograms 3 — Questions and Answers
Question 1: The skull and crossbones pictogram under WHMIS 2015 is applied to acute toxicity of which severity categories?
- Categories 1, 2, and 3 only (Correct answer)
- Categories 1 through 5
- Only Category 1 (most lethal)
- Categories 4 and 5 only
Correct answer: Categories 1, 2, and 3 only
The skull and crossbones pictogram covers acute toxicity Categories 1–3; Category 4 uses the less severe exclamation mark instead.
Question 2: Which WHMIS pictogram is used to signal long-term health hazards such as carcinogenicity, mutagenicity, and reproductive toxicity?
- Exclamation mark
- Skull and crossbones
- Health hazard (silhouette with starburst) (Correct answer)
- Biohazard symbol
Correct answer: Health hazard (silhouette with starburst)
The health hazard pictogram (a human silhouette with a starburst on the chest) covers chronic hazards including cancer, genetic damage, and reproductive effects.
Question 3: The exclamation mark pictogram in WHMIS is typically associated with which level of health hazard?
- Immediately fatal toxicity
- Carcinogenic and mutagenic effects
- Moderate hazards including skin/eye irritation and harmful effects (Correct answer)
- Explosive or reactive properties
Correct answer: Moderate hazards including skin/eye irritation and harmful effects
The exclamation mark signals moderate but real hazards such as skin sensitization, eye/skin irritation, and harmful (Category 4) acute toxicity.
Question 4: Which WHMIS pictogram is required on containers of biohazardous infectious materials?
- Skull and crossbones
- Biohazard symbol (overlapping circles/trefoil shape) (Correct answer)
- Health hazard silhouette
- Exclamation mark
Correct answer: Biohazard symbol (overlapping circles/trefoil shape)
The internationally recognized biohazard symbol is used exclusively for biohazardous infectious materials in WHMIS.
Question 5: A chemical capable of causing an allergic skin reaction (skin sensitization) upon repeated contact would display which WHMIS pictogram?
- Corrosion
- Skull and crossbones
- Exclamation mark (Correct answer)
- Health hazard
Correct answer: Exclamation mark
Skin sensitization (allergic contact dermatitis) is covered by the exclamation mark pictogram, not the health hazard pictogram.
Question 6: Which WHMIS hazard class exists in Canadian law but has no equivalent category in the international GHS system?
- Flammable liquids
- Oxidizing gases
- Biohazardous infectious materials (Correct answer)
- Corrosive to metals
Correct answer: Biohazardous infectious materials
Biohazardous infectious materials is a WHMIS-specific hazard class added to address biological hazards in Canadian workplaces, with no GHS counterpart.
Question 7: A solvent that causes liver damage after repeated workplace exposures falls under which WHMIS hazard classification?
- Acute toxicity (Category 1)
- Specific target organ toxicity – repeated exposure (STOT-RE) (Correct answer)
- Biohazardous infectious materials
- Corrosion (skin burns)
Correct answer: Specific target organ toxicity – repeated exposure (STOT-RE)
STOT-RE covers substances that cause damage to specific organs (such as the liver or kidneys) through repeated or prolonged exposure.
WHMIS Hazard Classes and Pictograms 3
The skull and crossbones pictogram under WHMIS 2015 is applied to acute toxicity of which severity categories?