We're sorry, but OSHAcademy doesn't work properly without JavaScript enabled. Please turn on JavaScript or install a browser that supports Javascript.

662 HAZWOPER for General Site Workers III
Skip to main content

What is a Hazardous Material?

Hazardous materials are defined and regulated in the United States primarily by laws and regulations administered by the U.S. Environmental Protection Agency (EPA), the U.S. Occupational Safety and Health Administration (OSHA), the U.S. Department of Transportation (DOT), and the U.S. Nuclear Regulatory Commission (NRC).

Hazardous Materials: General Awareness and Familiarization

The U.S. Department of Transportation (DOT) uses the term "hazardous materials" to cover substances in 9 hazard classes, some of which have subcategories called "divisions." The nine classes of hazardous materials are:

Responders here are inspecting a barrel of hazardous chemicals.
  1. Explosives
  2. Gases
  3. Flammable Liquid
  4. Flammable Solids
  5. Oxidizing Substances; Organic Peroxides
  6. Poisonous (Toxic) and Infectious Substances
  7. Radioactive Material
  8. Corrosives
  9. Miscellaneous Hazardous Goods

DOT includes in its regulations hazardous substances and hazardous wastes as Class 9 (Miscellaneous Hazardous Goods), both of which are regulated by the EPA.

Knowledge Check Choose the best answer for the question.

2-4. Identify one of the nine classes of hazards covered by the DOT's definition of "hazardous materials."