WHMIS (Workplace Hazardous Materials Information System) is a detailed system of labelling and information designed to inform workers who deal with hazardous goods. It is enforced by a number of governmental agencies in different localities.

There are two basic types of label from WHMIS; the supplier label and the workplace label. Both have symbols on them, but the supplier label is far more detailed.

All WHMIS labels have symbols on them; a list follows:

• A flame - The substance is flammable and should be kept away from sparks or flame. It might also be explosive.
• A flaming O - The substance is an oxidant.
• Drops from a vial corroding a hand and a metal bar - The substance is corrosive. Care should be kept to keep it away from skin and to prevent spillage.
• A skull and crossbones - The substance is poisonous and should not be taken internally.
• A T-like symbol with a dot below - The substance has "other toxic effects"
• An R which is being destroyed with a test tube in it - The substance is dangerously reactive with other substance.
• A tube-like canister - A compressed gas is contained
• A circle with three claw-like things coming out of it - Biohazard

WHMIS labels contain reference to the MSDS sheet associated with the product.

Material Classifications There are 6 classes of WHMIS materials:

• Class A Compressed Gas
• Class B Flammable and Combustible Material

 Division 1: Flammable Gas Division 2: Flammable Liquid Division 3: Combustible Liquid Division 4: Flammable Solid Division 5: Flammable Aerosol Division 6: Reactive Flammable Material 

• Class C Oxidizing Material
• Class D Poisonous and Infectious Material

 Division 1: Materials causing immediate and serious toxic effects Subdivision A: Very toxic material Subdivision B: Toxic material Division 2: Materials causing other toxic effects Subdivision A: Very toxic material Subdivision B: Toxic material Division 3: Biohazardous Infection Material 

• Class E Corrosive Material
• Class F Dangerously Reactive Material

further WHMIS Classification info (http://www.rccdsb.edu.on.ca/safety/whmis_classifications.htm)