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Chemical Hazards - Symbols

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.


Classification and Symbols

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.

 

 

 


Important Note:  A single material can have more than one hazard, which means that it could fit into more than one hazard class and have more than one symbol. Here, each symbol and class is discussed separately, but it is important to understand ALL hazards of any material you are using.

Class A - Compressed Gas


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

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

Hazards of Compressed Gases

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

do
USE only in a well-ventilated area.
 
HANDLE cylinders very carefully ? do not drag, roll, bang, knock, or drop cylinders.
 
SECURE cylinders in an upright position during storage or use. Often a chain is used to keep them from falling.
 
WEAR recommended personal protective equipment (e.g. protective gloves or goggles) to avoid direct contact with the gas.
 
UNDERSTAND and PRACTICE emergency procedures, including first aid, so that you know what to do in case of a spill or other emergency.


do not
NEVER ATTEMPT to move a cylinder or adjust the regulators, which control gas flow out of the cylinder, without supervision.
 
DO NOT HEAT, puncture or burn container even when empty.
 

Class B - Flammable and Combustible Material


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

Flammable and Combustible Material

  • 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:

Flammable and Combustible Material

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

do
USE only in a well-ventilated area.
 
KEEP containers closed when not in use or empty and your work area clean.
 
USE only the smallest amount of material necessary for the job.
 
ELIMINATE heat and ignition sources such as sparks, open flames, hot surfaces and static discharge.
 
KEEP your work area clear of materials that can burn (e.g. rags, piles of paper).
 
REPORT leaks, spills or failures of any safety equipment to your teacher or supervisor immediately .
 
UNDERSTAND and PRACTICE emergency procedures so that you know what to do in case of a spill or other emergency

 

 

 

do not
DO NOT POUR a flammable liquid from one container to another without special instruction or supervision.
 
DO NOT USE compressed air to clean equipment, clothing or spills.
 
DO NOT PUNCTURE or BURN container even if empty.
 

Class C - Oxidizing Material


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.

Class C - Oxidizing Material

Examples

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

 

Working Safely with Oxidizing Materials


Class C - Oxidizing Material

do
USE only in a well-ventilated area.
 
KEEP containers closed when not in use or empty and your work area clean.
 
USE only the smallest amount of material necessary for the job.
 
ELIMINATE heat and ignition sources such as sparks, open flames, hot surfaces and static discharge.
 
KEEP these materials AWAY from flammable or combustible materials and incompatible chemicals.
 
AVOID contamination by any source. Trace amounts of contaminant may cause dangerous chemical reaction(s).
 
INSPECT container and lid carefully for damage, leaks before handling.
 
REPORT leaks, spills or failures of any safety equipment to your teacher or supervisor immediately.
 
UNDERSTAND and PRACTICE emergency procedures so that you know what to do in case of a spill or other emergency.
 
USE only in a well-ventilated area.

 

 

 

 


do not
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.
 
NEVER RETURN unused or contaminated product to its original container.
 
NEVER REUSE empty containers, even if they appear to be clean.
 

Class D ? Poisonous and Infectious Material

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

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

materials causing immediate and serious toxic effects

Hazards of D1 Materials

Poisonous and Infectious Material

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

Poisonous and Infectious Material

  • Carbon monoxide
  • Ammonia
  • Chlorine
  • Sodium cyanide

 



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

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:

Hazards of D2 Material

  • 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

Hazards of D2 Material

  • 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


do
AVOID using these materials. Ask your teacher or supervisor if less hazardous materials can be used instead.
 
USE only in a well-ventilated area.
 
KEEP containers closed when not in use or empty and your work area clean.
 
USE only the smallest amount of material necessary for the job.
 
WEAR required personal protective equipment (PPE) to avoid direct contact.
 
AVOID ALL unprotected contact with these materials or contaminated equipment/surfaces.
 
KEEP these materials well away from where you eat or drink ? accidental ingestion is a serious concern
 
WASH your hands well after using these materials.
 
REPORT any symptoms you experience while handling these materials to your teacher or supervisor.
 
GET medical attention for all exposures. Symptoms can be delayed.
 
REPORT leaks, spills or failures of any safety equipment to your teacher or supervisor immediately.
 
UNDERSTAND and PRACTICE emergency procedures, including first aid, so that you know what to do in case of a spill or other emergency

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

do not
DO NOT WORK alone with very toxic materials.


— Division 3 (D3) —
Biohazardous Infectious Material

biohazardous infectious material

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

Biohazardous Infectious Material

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

do
AVOID handling or coming into contact with these materials.
 
ASSUME that any blood or body fluid is infectious.
 
EXERCISE caution when handling these materials or body fluids or items that may contain biohazardous materials.
 
BE EXTRA CAUTIOUS when handling sharp objects to avoid punctures.
 
COVER existing cuts with bandages and wear protective gloves (cuts are very vulnerable to infections).
 
WASH hands frequently and thoroughly any time you work with these materials or potentially infected items.
 
KEEP your hands away from your eyes, nose or mouth.
 
SANITIZE contaminated work areas.
 
TELL your teacher or supervisor immedicately if an injury occurs.
 

Class E - Corrosive Material


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.

Corrosive Material

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

Corrosive Material

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


do
AVOID using these materials. Ask your teacher or supervisor if less hazardous materials can be used instead.
 
USE only in a well-ventilated area.
 
KEEP containers closed when not in use or empty and your work area clean.
 
USE only the smallest amount of material necessary for the job.
 
WEAR required personal protective equipment (PPE) to avoid direct contact.
 
AVOID ALL unprotected contact with these materials or contaminated equipment/surfaces.
 
USE corrosion-resistant containers, tools and equipment.
 
REPORT leaks, spills or failures of any safety equipment to your teacher or supervisor immediately.
 
UNDERSTAND and PRACTICE emergency procedures, including first aid, so that you know what to do in case of a spill or other emergency.

 

 

 

 

 

 

 




do not
NEVER ADD water to a corrosive. Always add corrosives slowly to COLD water.
 
NEVER REUSE empty containers, even if they appear to be clean.
 

Class F - Dangerously Reactive Material


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

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.

 

Dangerously Reactive Material

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

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.




octagon

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

 

upside-down triangle
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
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
corrosive

This product can burn skin or eyes on contact, or throat and stomach if swallowed. Toilet bowl cleaner
Oven cleaner
      Flammable
flammable

This product or its vapour, can catch fire easily if it is near heat, flames or sparks. Contact adhesives
Solvents
           Toxic
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 Label

  • 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

FIRST AID TREATMENT

This product contains ammonia.

If splashed on eyes or skin, flush thoroughly with water.

If swallowed, drink 240-300 mL (8 to 10 oz.) of water.

DO NOT INDUCE VOMITING.
CALL PHYSICIAN OR POISON CONTROL CENTRE IMMEDIATELY.

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.

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