Canada Road & Rail Transport - Class 4 Divisions

Class 4 has three divisions.

Class 4.1, Flammable Solids, consists of substances that have the following characteristics:

• Readily combustible
• Under normal conditions of transport, liable to cause fire through friction
• Solid desensitized explosives
• Self-reactive substances that are liable to undergo a strongly exothermic decomposition even without the participation of oxygen
• Identified by one of the following UN numbers: UN2956, UN3241, UN3242 or UN3251
• Included in the list of currently assigned self-reactive substances in Section 2.4.2.3.2.3 of Chapter 2.4 of the UN Recommendations

Class 4.2, Substances Liable to Spontaneous Combustion, consists of pyrophoric substances that spontaneously ignite within five minutes after coming into contact with air; and of self-heating substances that, when in large amounts (kilograms), spontaneously ignite on contact with air after long periods (hours or days).

Class 4.3, Water-reactive Substances, consists of substances that, in tests, emit a flammable gas at a rate greater than 1 litre per kilogram of substance per hour or spontaneously ignite at any step in the test procedure.

To learn more about Transporting Dangerous Goods in Canada visit our Transporting Dangerous Good by Road & Rail Online Training web page.