Labels are usually the first indication that the contents are a controlled product. Labels should read carefully and thoroughly before using the product, especially if using the product for the first time or if it has been some time since you last used the product.

At University of Waterloo it is mandatory that every container is labelled as to its contents, whether it is a controlled product or not.

WHMIS supplier labels

These labels are applied, by the supplier, to a controlled product that is sold or imported to a workplace in Canada. If the supplier label becomes damaged, unreadable or falls off it must be replaced with a workplace label.

Items 1-6 are mandatory and will be found on the supplier label of any controlled product. Items 7-9 are included on the supplier label of any controlled product with a container size of more than 100 mL.

WHMIS supplier label

Workplace label

Workplace labels can be most commonly found on containers that have been decanted from larger containers but they can also be found on bulk containers.

As an absolute minimum a workplace label must have:

  1. Product identifier
  2. Safe handling instructions and
  3. Reference to MSDS

Additional information can be placed on a workplace label so that workers may gain a greater understanding of the material they are working with. Workplace labels used at UWaterloo may also contain;

  1. Hazard symbols
  2. Risk phrases
  3. Personal equipment symbols
  4. National fire prevention association diamond

The information for safe handling may be presented in any form, written or through the use of pictograms, as long as the information is understood by everyone in the workplace.

Below is a typical workplace label that can be found at UWaterloo.

whimis workplace label

Hazard symbols

The WHMIS program uses 8 distinctive symbols, seen here, to identify the 6 classes of hazardous materials. WHMIS has also established testing procedures and criteria that suppliers and manufacturers of materials to the Canadian workplace can use to determine if their products are hazardous.

The classes and symbols WHMIS uses to identify hazardous materials are:

Class Symbol

Class A - Compressed gas

Classifying material which is a gas at normal temperature and pressure, packaged under pressure in a cylinder or other container. Many of our laboratories and work areas use cylinders of various sizes and content such as compressed air, hydrogen or nitrogen.

whmis compressed gas

Class B - Flammable and combustible materials

Classifying material that will ignite and continue to burn in air if exposed to a source of ignition. This class includes gases, aerosols, liquids and solids. Many laboratory solvents and cleaning materials used on campus fall into this class.

flammable combustable icon

Class C - Oxidizing materials

This symbol identifies material that releases oxygen or other oxidizing substances and thereby contributing to the combustion of other flammable materials. Oxidizers such as chlorine, nitrogen dioxide and hydrogen peroxide are found in many of our laboratories.

oxidixing material

Class D - Division 1: Materials causing immediate and serious toxic effects

The skull and cross bones identifies acutely toxic material. These materials can severely damage our health in a single overexposure. Fortunately, few of our work areas contain this type of material. Examples are cyanide compounds, styrene.

toxic effects

Class D- Division 2: Materials causing other toxic effects

This unique symbol identifies material that poses a threat to our health through long term exposure. Further, this material may be a suspected carcinogen or have other health damaging properties. Our labs, work areas and shops contain materials marked with symbol.

toxic effects 2

Class D - Division 3: Biohazardous infectious materials

This distinctive symbol identifies material that presents the risk or danger of biological or viral infection on contact. Very few areas of the University use or produce material marked with this symbol. Containers for biomedical waste and used syringes, needles and sharps are marked with this symbol.

biohazardous material

Class E - Corrosive material

Corrosive material can attack metals and other substances and can cause permanent damage to human tissues and organs. Fumes from these material can also damage our internal organs. Strong acids, ammonia and fluorine are examples of corrosives.

corrosive material

Class F - Dangerously reactive material

This symbol identifies dangerously reactive materials. These materials may react violently under certain conditions or react violently with water. Few of our work areas use or store these materials.

radioactive material

Personal protective equipment symbols

These are a few of the symbols you may encounter that indicate what Personal Protective Equipment (PPE) must be worn when handling a particular hazardous material. This is not an exhaustive list, if you encounter a symbol you are unsure of contact the Safety Office for clarification.

Personal protective equipment Symbol
Dust mask required - A NIOSH approved N95 dust mask must be used. dusk mask
Air purifying respirator - A NIOSH approved chemical cartridge respirator must be used. Use of this type of respirator requires specialized training - contact the Safety Office before using for approval and training. air purifying respirator
Supplied air respirator - A NIOSH approved SCBA or Supplied Air system must be used. Use of this type of respirator requires specialized training - contact the Safety Office before using for approval and training. supplied air respirator
Apron - An apron made of material resistant to the hazardous material must be worn. Consult your supervisor or the material's MSDS for further information. apron
Chemical protective clothing - Either a hooded or fully-encapsulating suit of appropriate material must be worn. Consult MSDS for appropriate level of protection. Use of this type of PPE requires specialised training - contact the Safety Office before using for approval and training. chemical protective clothing
Goggles - C.S.A. approved chemical-resistant, splash-proof goggles must be worn. Goggles
Face shield - C.S.A. approved face shield must be worn. Note: C.S.A. approved safety glasses or goggles must also be worn with this device. Face shields
Foot protection - - C.S.A. approved protective footwear appropriate to the hazard must be worn. boots
Hand protection - Gloves offering appropriate protection to the hazard must be worn. Consult with your supervisor of the material's MSDS for further information. gloves

National fire prevention association diamond

This describes the NFPA diamond on found on many workplace labels here at UWaterloo.

NFPA diamondSpecific hazards

Risk number code Hazard (1) Fire risk (2) Health risk (3) Reactivity risk (4)
0 Minimal Will not burn Non-hazardous Non-reactive
1 Low Flash point > 93.3°C Slightly hazardous Normally stable; may become unstable if heated or may react with water, but not violently
2 Moderate

Flash point >37.8°C but <93.3°C 

Must be exposed to relatively high ambient temperatures before ignition can occur
Intense or continued exposure could cause temporary incapacitation or possible residual injury without prompt medical treatment Unstable, readily undergoes violent chemical change
3 Serious Can be ignited under almost all ambient temperature conditions Extremely hazardous. Short exposure could cause serious temporary or residual injury even with treatment, or could cause death Capable of detonation or explosive reaction, but requires a strong detonating source
4 Extreme Will rapidly vaporize at atmospheric pressure and normal ambient temperature, or will readily disperse in air and will burn readily Deadly May detonate