Hazardous waste materials are designated by the United States Secretary of Transportation to be a waste item or substance that poses an unreasonable threat to the public and/or the environment. Hazardous materials regulated by the U.S. DOT are classified as follows: Class 1: Explosives o Mass Explosive Hazard o Projection Hazard o Mass Fire Hazard o Minor Explosion Hazard o Very Insensitive Explosives o Extremely Insensitive Explosives Class 2: Gases o Flammable Gases o Non-flammable Gases o Poisonous or Toxic Class 3: Flammable Liquid Class 4: Flammable Solids o Flammable Solid o Spontaneously Combustible Material o Dangerous When Wet Class 5: Oxidizing Substances; Organic Peroxides o Oxidizer o Organic Peroxide Class 6: Poisonous (Toxic) and Infectious Substances o Poisonous (Toxic) Material o Infectious Substances Class 7: Radioactive Material Class 8: Corrosives Class 9: Miscellaneous Dangerous Goods o Environmentally Hazardous Substances, Elevated Temperature Material, Hazardous Wastes, and Marine Pollutants
