WHMIS Symbols – (Classes or Classification)

WHMIS Symbols – (Classes or Classification)

It is the responsibility of the supplier/manufacturer to classify the product.  You can see the WHMIS Symbols below. Using Part IV of the Controlled Product Regulation, the supplier must compare the properties of their product to the criteria outlined in the Regulation to determine whether or not it is considered a controlled product.  The supplier may be required to perform tests on the product in question to make this determination.

WHMIS Symbols

WHMIS Symbols

 

A controlled product is one that meets the criteria outlined in Part IV of the Controlled Product Regulation.  There are 6 classes in total; identified as A, B, C, D, E and F.  Classes B and D are broken into subdivisions.  The 6 classes are represented by 8 WHMIS symbols or pictograms, each contained in a circle.

Class A: Compressed Gas

Class A: Compressed Gas

Class A: Compressed Gas

Any hazardous material that is contained under pressure including compressed gas, dissolved gas, or liquefied gas.

Compressed gases are dangerous because the material has been pressurized or refrigerated and contained in a cylinder.  If the cylinder or the valve is damaged, the material will want to escape rapidly; turning the cylinder into a missile.  Heating the cylinder could cause the gas to expand resulting in the cylinder bursting or exploding.

Compressed gases can be inert or may have other dangerous or hazardous properties.  The gas contained within the cylinder may be an oxidizer, poisonous, corrosive or flammable.  Leaking cylinders may cause frostbite like burns if it makes contact with the skin, or it could fill low lying areas with flammable or toxic gas.

Examples of compressed gases include Oxygen, Nitrogen, Acetylene, Chlorine, Argon, Propane and Helium.

Safe handling precautions include transporting and handling the cylinders with care and ensuring they are secured upright to prevent damage to the cylinder or the valve.  It is also important to consider where the cylinders are being stored; essentially away from sources of heat or fire and outside when applicable. You can consult WHMIS online training software for more information about WHMIS safety with regard to compressed gas.

Class A hazards are represented by a picture of a cylinder contained in a circle.

Class B: Flammable and Combustible

Class B: Flammable and Combustible

Class B: Flammable and Combustible

Any hazardous material that may burn, explode or spontaneously combust when exposed to heat, sparks, flames or pressure.  These materials may have the ability to evaporate quickly and give off vapours which when combined with air can ignite and continue to burn.  Combustibles require higher temperatures to ignite than flammables.  It is important to use WHMIS training courses to ensure that all employees understand the categories of flammable and combustible substances. Flammable and combustible materials are subdivided into 6 divisions:

B1 – Flammable Gases

Meets the requirements for Class A and mixes with air to form a flammable mixture under normal atmospheric pressure

B2 – Flammable Liquids

Liquids with a flashpoint less than 37.8 C

B3 – Combustible Liquids

Liquids with a flashpoint between 37.8 C and 93.3 C

B4 – Flammable Solids

Solid material, including dust and powder, that readily ignite and burn

B5 – Flammable Aerosols

Material packaged in an aerosol container and is capable of projecting a flame or flashback

B6 – Reactive Flammable Material

Material that is capable of spontaneous combustion under normal circumstances and materials that are capable of producing flammable gases when mixed with water

Examples of flammable and combustible materials include Gasoline, Diesel Fuel, Kerosene, Acetylene, Propane and Toluene

Safety precautions include observing appropriate storage locations; away from oxidizers and sources of ignition.  Sources of ignition consist of open flames, hot surfaces, static electricity, sparks created from cutting, welding and electricity, radiant heat and friction.  Prevent static when dispensing by grounding and bonding containers and ensure waste products are properly disposed of.

Class B hazards are represented on a WHMIS label with a picture of a fire contained in a circle.

Class C: Oxidizing Materials

Class C: Oxidizing Materials

Class C: Oxidizing Materials

Any Hazardous Material which releases oxygen and contributes to the combustion of another material.  With the exception of organic peroxides, oxidizers do not generally burn but they do provide the oxygen necessary for a fire; therefore, oxidizers will cause a fire to burn faster, longer and hotter.

Examples include: Chlorine, Sulfuric Acid, Chromic Acid, Nitrates some Bleaches and Fluroine

WHMIS safety precautions include storing separately away from flammable and combustible materials.

Class C hazards are represented by a picture of the letter ‘O’ on fire contained in a circle.

Class D: Poisonous and Infectionous

Any hazardous material which may damage the body or cause illness from irritation up to and including death.  According to the Workplace Hazardous Materials Information System, Poisonous and Infectious materials are subdivided into 3 divisions. The different subdivisions of Class D hazardous materials have their own WHMIS symbols.

Class D1: Immediate Serious Toxic Effects

Class D1: Immediate Serious Toxic Effects

Poisonous and Infectious. Class D1: Immediate Serious Toxic Effects

Any hazardous material which is fatal or immediately threatening to human health.  Materials in this WHMIS class may affect the body shortly following a single exposure resulting in burns to the skin or eyes.  These materials may also cause permanent damage after brief exposure if inhaled, swallowed or absorbed through the skin.

Examples include: Methanol, Carbon Monoxide, Sodium, Acetone and Hydrogen Sulphide

WHMIS training and safety precautions include avoid inhaling gas or vapours, avoid skin and eye contact by wearing the recommended protective equipment and clothing.  Do not eat, drink or smoke near these materials and wash hands after handling.

Class D1 hazards are represented by a picture of a skull and cross bones contained in a circle.

Class D2: Other Toxic Effects

Class D2: Other Toxic Effects

Poisonous and Infectious. Class D2: Other Toxic Effects

Any hazardous material which may cause death or permanent damage as a result of repeated exposure over an extended period time.   Health effects are not always recognized immediately and may range from an irritant to the skin, eyes or respiratory system; up to and including cancer, birth defects, or sterility.

Examples include: Asbestos, Mercury, Acetone, Benzene

Precautions include avoid inhaling gas or vapours, avoid skin and eye contact by wearing the recommended protective equipment and clothing.  Do not eat, drink or smoke near these materials and wash hands after handling.

Class D2 hazards are represented by a picture of the letter ‘T’ with the dot of an exclamation point contained in a circle.

Class D3: Biohazardous and Infectious

Class D3: Biohazardous and Infectious

Poisonous and Infectious. Class D3: Biohazardous and Infectious

Any hazardous material which has the potential to corrode aluminum or steel or burn human flesh, eyes or skin.  Corrosive materials may cause permanent damage to the respiratory system if inhaled.

Examples include Sulphuric Acid, Nitric Acid, Chlorine, Ammonia, Caustic Soda

Safety precautions include storing acids and bases in separate areas.  Avoid inhaling and making contact with skin and eyes and wear the recommended protective equipment and clothing. For more information on WHMIS safety standards for corrosive substances, it is important to consult a WHMIS online training program or WHMIS training manual.

Class E hazards are represented by a picture of a piece of metal and a hand, both with a test tube pouring liquid onto them contained in a circle.

Class E: Corrosive

Class E: Corrosive

Class E: Corrosive

Any hazardous material which has the potential to corrode aluminum or steel or burn human flesh, eyes or skin.  Corrosive materials may cause permanent damage to the respiratory system if inhaled.

Examples include Sulphuric Acid, Nitric Acid, Chlorine, Ammonia, Caustic Soda

Safety precautions include storing acids and bases in separate areas.  Avoid inhaling and making contact with skin and eyes and wear the recommended protective equipment and clothing.

Class E hazards are represented by a picture of a piece of metal and a hand, both with a test tube pouring liquid onto them contained in a circle.

Class F: Dangerously Reactive

Class F: Dangerously Reactive

Class F: Dangerously Reactive

Any hazardous material which may undergo vigorous polymerization, decomposition, or condensation, become self-reactive under conditions of shock, increased temperature or pressure; or materials which react vigorously with water to produce a very toxic gas.

Examples: Styrene, Nitroglycerine, Acetylene, Calcium Carbide, Aluminum Chloride, Acetonitrile

Precautions include being aware of possible reactions and avoid mixing with incompatible materials.  Do not heat, drop or otherwise misuse these products.  Store appropriately, away from other materials, in a cool location if necessary.

Class F hazards are represented by a picture of the letter ‘R’ with a test tube contained in a circle.

Exemptions from WHMIS

Not all hazardous products are controlled products and are therefore exempted from WHMIS.  These products remain hazardous and are controlled through other legislation such as the Consumer Product Safety Act and the Pest Control Products Act.  These exemptions are listed below:

  • Explosives
  • Cosmetics, drugs, medical devices and foods
  • Pesticides and disinfectants
  • Radioactive materials
  • Consumer restricted products
  • Wood and wood products
  • Tobacco
  • Manufactured articles