There are 9 hazard classes for fully regulated items according to the U.S. Department of Transportation (DOT). These classes cover all types of hazardous materials and dangerous goods and are used to regulate their safe handling, packaging, and transportation. The classes are:
- Class 1: Explosives
- Class 2: Gases
- Class 3: Flammable Liquids
- Class 4: Flammable Solids, Spontaneously Combustible, and Dangerous When Wet
- Class 5: Oxidizers and Organic Peroxides
- Class 6: Poisons (Toxic) and Infectious Substances
- Class 7: Radioactive Materials
- Class 8: Corrosive Materials
- Class 9: Miscellaneous Hazardous Materials
Each class may include divisions or subclasses that specify the nature of the hazard more precisely (e.g., Class 1 explosives have six divisions based on the type of explosion hazard)
. These nine classes represent the fully regulated hazardous materials under the Hazardous Materials Regulations (HMR), meaning all regulatory requirements apply unless specific exemptions are noted. Some items may be partially regulated under certain conditions, but the classification system itself includes these nine classes for fully regulated items
. In summary, the number of hazard classes for fully regulated items is nine.
