Aviation - Hazard Classes

All HAZMAT employees must be able to accurately identify the various classes of hazardous materials defined by the HMR. The nine hazard classes and other regulated material defined in the HMR are capable of posing a risk to health, safety, and property when transported. Hazardous materials classes 1-9 specifics may be found in §173 of the HMR.

The nine hazard classes are:

• Class 1 - Explosives
• Class 2 - Gases
• Class 3 - Flammable liquids
• Class 4 - Flammable solids; substances liable to spontaneous combustion; substances which, in contact with water, emit flammable gases
• Class 5 - Oxidizing substances and organic peroxides
• Class 6 - Toxic and infectious substances
• Class 7 - Radioactive material
• Class 8 - Corrosives
• Class 9 - Miscellaneous dangerous goods

Please note that the class numbers are for convenience only; they DO NOT indicate a relative degree of danger.

To learn more about Aviation HAZMAT visit our DOT Aviation HAZMAT Online Training web page.