Pictograms are graphic images that immediately show the user of a hazardous product what type of hazard is present. With a quick glance, you can see, for example, that the product is flammable or that it might be a health hazard.

Most pictograms have a distinctive red "square set on one of its points" border. Inside this border is a symbol that represents the potential hazard (e.g., fire, health hazard, corrosive, etc.). Together, the symbol and the border are referred to as a pictogram. Pictograms are assigned to specific hazard classes or categories.

The graphic below shows hazard pictograms. The bold type is the name given to the pictogram; the words in the brackets describe the hazard.

The following pictograms are associated with these hazard classes and categories.

The flame pictogram is used for the following classes and categories:

• Flammable gases (Category 1A and 1B Flammable gas; Category 1A and 1B Chemically unstable gas; Category 1A Pyrophoric gas) )
• Aerosols (Category 1 and 2)
• Flammable liquids (Category 1, 2 and 3)
• Flammable solids (Category 1 and 2)
• Pyrophoric liquids (Category 1)
• Pyrophoric solids (Category 1)
• Self-heating substances and mixtures (Category 1 and 2)
• Substances and mixtures which, in contact with water, emit flammable gases (Category 1, 2 and 3)
• Self-reactive substances and mixtures (Types B*, C, D, E and F)
• Organic peroxides (Types B*, C, D, E and F)
• Chemicals under pressure (Category 1** and 2**) 

The flame over circle pictogram is used for the following classes and categories:

• Oxidizing gases (Category 1)
• Oxidizing liquids (Category 1, 2 and 3)
• Oxidizing solids (Category 1, 2 and 3)

The gas cylinder pictogram is used for the following classes and categories:

• Gases under pressure (Compressed gas, Liquefied gas, Refrigerated liquefied gas, and Dissolved gas)
• Chemicals under pressure (Category 1**, 2** and 3) 

The corrosion pictogram is used for the following classes and categories:

• Corrosive to metals (Category 1)
• Skin corrosion/irritation – Skin corrosion (Category 1, 1A, 1B and 1C)
• Serious eye damage/eye irritation – Serious eye damage (Category 1)

The exploding bomb pictogram is used for the following classes and categories:

• Self-reactive substances and mixtures (Types A and B*)
• Organic peroxides (Types A and B*)

The skull and crossbones pictogram is used for the following classes and categories:

• Acute toxicity –
  • Oral (Category 1, 2 and 3)
  • Dermal (Category 1, 2 and 3)
  • Inhalation (Category 1, 2 and 3)

The health hazard pictogram is used for the following classes and categories:

• Respiratory or skin sensitization – Respiratory sensitizer (Category 1, 1A and 1B)
• Germ cell mutagenicity (Category 1, 1A, 1B and 2)
• Carcinogenicity (Category 1, 1A, 1B, and 2)
• Reproductive toxicity (Category 1, 1A, 1B and 2)
• Specific Target Organ Toxicity – Single exposure (Category 1 and 2)
• Specific Target Organ Toxicity – Repeated exposure (Category 1 and 2)
• Aspiration hazard (Category 1)

The exclamation mark pictogram is used for the following classes and categories:

• Acute toxicity – Oral, Dermal, Inhalation (Category 4)
• Skin corrosion/irritation – Skin irritation (Category 2)
• Serious eye damage/eye irritation – Eye irritation (Category 2 and 2A)
• Respiratory or skin sensitization – Skin sensitizer (Category 1, 1A and 1B)
• Specific target organ toxicity – Single exposure (Category 3)

The biohazardous infectious materials pictogram is used for the following classes and categories:

• Biohazardous Infectious Materials (Category 1)

* Both the Flame and Explosive pictograms are used for Self-reactive substances and mixtures (Type B) and Organic peroxides (Type B).

** Both the Flame and Cylinder pictograms are used for Chemicals under pressure, categories 1 and 2.  

NOTE: Physical Hazards Not Otherwise Classified and Health Hazards Not Otherwise Classified classes are required to have a GHS pictogram that is appropriate to the hazard identified.

No. There are hazardous products that meet the criteria for a hazard class or category, but these classes and categories do not require a pictogram. The product label and Section 2 (Hazards Identification) of the SDS still require the signal word, hazard statement(s), and other required label elements.

WHMIS classes and categories that do not require a pictogram are:

• Aerosols - Category 3
• Flammable gases – Category 2
• Flammable liquids – Category 4
• Self-reactive substances and mixtures – Type G
• Organic peroxides – Type G
• Combustible dusts – Category 1
• Simple Asphyxiants – Category 1
• Serious eye damage/eye irritation – Eye Irritation – Category 2B
• Reproductive toxicity – Effects on or via lactation

Pictograms will be on the product supplier labels of the hazardous products you work with. They will also be on the SDSs (as the symbol or words that describe the symbol). Please see the following for more information:

• WHMIS - Labels
• WHMIS - Safety Data Sheets (SDSs)

You may also be interested in our WHMIS Pictograms poster and our WHMIS Pictograms Kit.