The Hazard Classes

The generator must label and mark each container of hazardous waste, as outlined in 49 CFR 172.44. The labeling requirements for hazardous waste packages are complex. In general, all packages must display a diamond-shaped hazardous-materials label that identifies the hazard class of the hazardous waste material.

The hazard classes are as follows:

• Class 1: Explosives
• Class 2: Gases
• Class 3: Flammable Liquids
• Class 4: Flammable Solids, Spontaneously Combustible Materials, and Dangerous When Wet Materials
• Class 5: Oxidizers and Organic Peroxides
• Class 6: Poisonous Materials and Infectious Substance
• Class 7: Radioactive Materials
• Class 8: Corrosives
• Class 9: Miscellaneous Hazardous Materials and General Danger

The label must also include the identification number of the hazardous waste. This number is the number of its hazard class. For example, the identification number for Radioactive Material is 7. Some of the identification numbers include a decimal. For example, the identification number for oxidizers is 5.1, and for organic peroxide, it is 5.2. The numbers for the category of explosives reflect the type and level of explosion hazard the material exhibits. For instance, "Explosive 1.1" indicates that a material has the potential for a mass explosion. This label would be needed for some types of spent ammunition. In contrast, the label "Explosives 1.5" indicates a very insensitive explosive. A 1.5 explosive has a mass explosive hazard, but there is little chance of explosion under normal conditions of transport. For instance, this label would be used with pelletized ammonium nitrate-fuel oil mixture.

To learn more about RCRA visit our RCRA Hazardous Waste Safety Online Training web page.