• > Class A - Compressed Gasses
• > Class B - Flammable and Combustible Material
• > Class C - Oxidizing Material
• > Class D - Poisonous and Infectious Material
• > Class E - Corrosive Material
• > Class F - Dangerously Reactive Material
• > Consumer Products

WHMIS (Workplace Hazardous Materials Information System) helps identify the hazards of materials like chemical products and infectious agents. Information including physical, chemical and environmental characteristics and toxicity information (health effects) is collected about the product and its components. The collected information is then evaluated and assessed to determine the potential physical (fire and reactivity), health and environmental hazards of the product.

WHMIS groups products with similar properties or hazards into classes. The Controlled Products Regulations specifies the criteria used to place materials within each classification. WHMIS classifications are made by the manufacturer or supplier for products to be used in Canada.

There are six (6) main WHMIS hazard classes. In general, each class has a specific symbol to help people quickly recognize the hazard. However, one hazard class has three (3) symbols ? so there are a total of eight (8) symbols.

Class A - Compressed Gas

A compressed gas is a material that is a gas at normal room temperature and pressure. The gas is placed under pressure or chilled to contain it, usually in a cylinder.

Hazards of Compressed Gases

• Explosion ? Puncturing, damaging, banging, knocking over or dropping the cylinder or allowing the cylinder to become hot could result in an explosion or cause the cylinder to rocket or spin out of control causing serious injury or property damage.
• Suffocation ? Compressed gas cylinders contain a huge volume of gas. A leak in a small or poorly ventilated area could displace oxygen in the air, causing suffocation.
• Frostbite ? Gas escaping from a cylinder can be extremely cold. Severe frostbite can lead to serious, permanent skin damage.

Examples

Compressed propane is used as a fuel for barbequing.

Compressed helium is used to inflate balloons.

Compressed acetylene is used for welding.

Compressed carbon dioxide is used in some fire extinguishers.

Working Safely with Compressed Gases

USE only in a well-ventilated area.

NEVER ATTEMPT to move a cylinder or adjust the regulators, which control gas flow out of the cylinder, without supervision.

Class B - Flammable and Combustible Material

These materials can catch fire easily, at or just above normal room temperatures, and continue to burn.

Flammable liquids catch fire more readily than combustible liquids. Reactive flammable materials can react with air or water and catch fire. It is unlikely that you will be working with a Reactive Flammable Material.

Hazards of Flammable and Combustible Materials

• Fire or explosion — can be caused by the combination of fuel (such as a flammable liquid), air, and an ignition source (e.g. sparks, flames, friction, hot surfaces, static electricity, light switches and other electrical devices such as power tools).

 

 

Examples

There are six divisions to this class:

B1 ? Flammable gases: hydrogen, acetylene, propane

B2 ? Flammable liquids: gasoline, toluene, acetone (in many nail polish removers)

B3 ? Combustible liquids: diesel fuel, kerosene, formaldehyde solutions

B4 ? Flammable solids: silicon, naphthalene

B5 ? Flammable aerosols: aerosol products that contain propane or butane as the propellant (e.g. some hair sprays)

B6 ? Reactive flammable materials: lithium, zinc powder

Working Safely with Flammable and Combustible Materials

USE only in a well-ventilated area.

DO NOT POUR a flammable liquid from one container to another without special instruction or supervision.

Class C - Oxidizing Material

An oxidizing material can decompose readily to release oxygen or another oxidizing substance.

Hazards of Oxidizing Materials

Cause or speed up a fire or explosion.

Cause materials to burn rapidly that do not normally burn readily.

Cause combustible materials (like rags) to burn, even without an ignition source like a spark or flame.

Examples

• Ozone (gas)
• Hydrogen peroxide (liquid)
• Calcium hypochlorite (solid), used in swimming pools

Working Safely with Oxidizing Materials

USE only in a well-ventilated area.

DO NOT ATTEMPT to open container or use product if it looks different than the product description given on the MSDS (e.g. colour change, crystal formation). Tell your teacher or supervisor.

These materials can cause harmful health effects. There are three divisions to this class.

— Division 1 (D1) —
Materials Causing Immediate and Serious Toxic Effects

Hazards of D1 Materials

These materials can cause serious health effects and death following a single dose or brief exposure. These materials are called "Very toxic" or "Toxic" depending on how much you need to be exposed to and for how long to cause the effect.

Examples

• Carbon monoxide
• Ammonia
• Chlorine
• Sodium cyanide

— Division 2 (D2) —
Materials Causing Other Toxic Effects

Hazards of D2 Materials

These materials cause a wide range of harmful effects. Some of these effects are more serious and are referred to as ?Very Toxic? effects, for example:

• cancer,
• birth defects in your children,
• asthma,
• reproductive effects, and
• long-term health effects, like liver damage, from a relatively low exposure.

Other effects are less serious and are referred to as "Toxic" effects, for example:

• skin irritation,
• eye irritation,
• allergic skin reactions, and
• long-term health effects, like liver damage, from a relatively high exposure.

Examples

• Asbestos causes cancer.
• Lead causes birth defects and reproductive effects.
• Carbon tetrachloride causes liver damage.
• Acetone is an eye irritant.
• Latex is a skin sensitizer.

Working Safely with D1 and D2 Materials

AVOID using these materials. Ask your teacher or supervisor if less hazardous materials can be used instead.

DO NOT WORK alone with very toxic materials.

— Division 3 (D3) —
Biohazardous Infectious Material

These materials are organisms such as bacteria, viruses, fungi and parasites that cause diseases. Because these organisms can live in body tissues or fluids (blood, urine), the tissues and fluids are also treated as toxic.

Typically, biohazardous infectious materials are found in hospitals, laboratories, veterinary practices and research facilities.

Hazards of Biohazardous Infectious Materials

These materials may cause serious illness, disease and/or death.

Examples

• E. coli (e.g. in raw or undercooked meat)
• HIV virus (AIDS) or Hepatitis B (in blood or blood products)

Working Safely with Biohazardous Materials

AVOID handling or coming into contact with these materials.

Class E - Corrosive Material

These materials can cause severe burns and possibly permanent damage to human tissues such as skin, eyes and lungs, and/or can attack or corrode metals.

Hazards of Corrosive Materials

Can burn or destroy human tissue (e.g. skin and eyes) immediately on contact.

Can cause permanent scarring, blindness, lung injury, or death with severe exposures.

Can attack (corrode) some metals making them weak and eventually leading to collapse. For example, corroded containers can spill contents and corroded metal equipment can collapse.

Examples

Acids (e.g. sulfuric acid) ? found in car batteries

Bases (e.g. sodium hydroxide) ? found in drain clearing products

Chlorine ? found in cleaning products

Sodium hypochlorite ? found in bleach

Working Safely with Corrosive Materials

AVOID using these materials. Ask your teacher or supervisor if less hazardous materials can be used instead.

NEVER ADD water to a corrosive. Always add corrosives slowly to COLD water.

Class F - Dangerously Reactive Material

These materials are unstable or highly reactive materials that can undergo extremely hazardous uncontrolled reactions.

Stabilizers or inhibitors are added to most Dangerously Reactive Materials to reduce or eliminate the hazard. It is unlikely that you will work with these materials.

Hazards of Dangerously Reactive Material

Serious health effects and death — these materials can react very strongly and quickly with water to release a very toxic gas.

Fire or explosion — these materials react dangerously under certain circumstances, for example if:

• bumped or dropped,
• the temperature increases, or
• the pressure increases.

Examples

• Ethyl acrylate
• Vinyl chloride
• Benzoyl peroxide

Working Safely with Dangerously Reactive Materials

Very specialized training is required to work safely with these materials.

Consumer Products

Consumer products are chemical products sold to Canadians for general household use that have certain hazards (such as toxic, corrosive, flammable). Consumer Products use different symbols than WHMIS.

Consumer Product symbols are framed by one of two shapes, which signify whether it is the contents of the container or the container itself that is dangerous.

An octagon (stop sign) means the contents of the container are dangerous.

 

The upside-down triangle means that the container is dangerous.

The following table lists the types of hazards identified on consumer products.

Symbol	Danger	Product Examples
Explosive	This container can explode if it is heated or punctured. Flying pieces of metal or plastic can cause serious injuries, especially to the eyes.	Water repellant for shoes or boots in an aerosol container Spray paint in an aerosol container
Corrosive	This product can burn skin or eyes on contact, or throat and stomach if swallowed.	Toilet bowl cleaner Oven cleaner
Flammable	This product or its vapour, can catch fire easily if it is near heat, flames or sparks.	Contact adhesives Solvents
Toxic	Licking, eating, drinking, or sometimes smelling, this product can cause illness or death.	Windshield washer fluid Furniture polish

Adapted from: Stay Safe - A Safety Education Guide to Household Chemical Products for Children 5 to 9 years of age. Consumer Product Safety (CPS), Health Canada. Available online at: http://www.hc-sc.gc.ca/cps-spc/pubs/indust/stay_safe_chem-soyez_securite_chim/index-eng.php

Below the symbol will appear a signal word. The signal words and their meaning are:

• CAUTION means temporary injury may be frequent. Death may occur with extreme exposure.
• DANGER means may cause temporary or permanent injury or death.
• EXTREME DANGER means exposure to very low quantities may cause death or temporary or permanent injury.

• The back or side label of regulated containers will always have some type of bordered area. Inside the border, you will find safety instructions, the words FIRST AID TREATMENT along with instructions in case of injury and a list of harmful substances in the product.

Example

Note: Consumer Products are partially covered under WHMIS — an MSDS is not required, but employers must still train employees on the hazards and safe handling procedures for these products.