The Canadian government created the Workplace Hazardous Materials Information System--WHMIS--as a way to inform Canadian workers about the possible dangers of products they may encounter at work, according to the Canadian Centre for Occupational Health and Safety. Although there are thousands of products controlled by WHMIS, all products fall into one of six product classes.
Compressed Gas
WHMIS controls products such as carbon dioxide, propane or welding gases, because these pressurized gases will cause injury to workers if their cylinders break or leak, according to the Canadian Centre for Occupational Health and Safety.
If workers expose the cylinders to heat, there is also a risk of explosion or fire. WHMIS regulations stipulate that these products must display a government-approved symbol for a container of pressurized gas, surrounded by a circle, to warn workers of the potential hazards of working with these products.
Flammable and Combustible Material
Turpentine, kerosene and spray paint are examples of flammable and combustible materials controlled by WHMIS, notes the CCOHS. These products will catch fire at temperatures of 100 degrees or greater, or will react with water or air to create flammable gas. WHMIS regulations set up subclasses within this category of product for solid, liquid or gaseous materials. The CCOHS reports that flammable or combustible products must carry a symbol of flames in a circle to warn workers of potential danger.
Poisonous and Infectious Material
WHMIS regulations separate poisonous and infectious materials into three main divisions: those products that will cause immediate death, poisonous materials with toxic effects that are not immediate and biohazards.
Carbon monoxide, sodium cyanide and sulfuric acid are examples of products that will cause immediate death; these products must carry a symbol featuring a skull and crossbones within a circle. CCOHS notes that lead, mercury and benzene are products that WHMIS considers not immediately toxic, but still dangerous; the symbol that warns workers of the dangers of these products looks like a combination of "T" and an exclamation point.
Biohazards are materials saturated with infectious organisms that can cause disease in humans, such as salmonella or the HIV virus. The CCOHS describes the biohazard symbol as three interlocking "C"s with a small circle in the middle.
