Transport Canada's Transportation of Dangerous Goods Regulations divides dangerous goods into nine classes according to the type of hazard involved:

Class 1 - Explosives

Class 2 - Gases

Class 3 - Flammable Liquids

Class 4 - Flammable Solids

Class 5 - Oxidizing Substances

Class 6 - Toxic and Infectious Substances

Class 7 - Radioactive Materials

Class 8 - Corrosives

Class 9 - Miscellaneous