International Maritime Dangerous Goods (IMDG) Classes

Class 1 – Explosives

1.1 Substances and articles which have a mass explosion hazard.
1.2 Substances and articles which have a projection hazard but not a mass
1.3 Substances and articles which have a fire hazard and either a minor blast hazard or a minor projection hazard or both, but not a mass explosion hazard.
1.4 Substances and articles which present no significant hazard.
1.5 Very insensitive substances which have a mass explosion hazard.
1.6 Extremely insensitive articles which do not have a mass explosion.

Class 2 – Gases: Compressed, Liquefied or Dissolved under Pressure

2.1 Flammable gases
2.2 Non-Flammable gases
2.3 Toxic gases

Class 3 – Flammable Liquids

Class 4 – Flammable Solids or Substances

4.1 Flammable solids
4.2 Substances liable to spontaneous combustion
4.3 Substances which, in contact with water, emit flammable gases.

Class 5 – Oxidizing Substances (agents) and Organic Peroxides

5.1 Oxidizing substances (agents) by yielding oxygen increase the risk and intensity of fire
5.2 Organic peroxides – most will burn rapidly and are sensitive to impact or friction

Class 6 – Toxic and infectious Substances

6.1 Toxic substances
6.2 Infectious substances

Class 7 – Radioactive Substances

Class 8 – Corrosives

Class 9 – Miscellaneous dangerous substances and articles *

MHB – Materials hazardous only in bulk **