• The hazardous waste number must be marked on the hazardous waste container prior to shipping offsite and must be included on the hazardous waste manifest.
• The hazard codes indicate the basis for the waste being included in the hazardous waste lists.

Industry and EPA Hazardous waste numbers

The F, K, P, and U lists also include the Environmental Protection Agency (EPA) hazardous waste number for each waste. This number is important because it must be marked on the hazardous waste container prior to shipping offsite and must be included on the hazardous waste manifest. Sometimes the hazardous waste number is also referred to as the hazardous waste code, but this should not be confused with the hazard code.

There are 149 Industry and EPA hazardous waste numbers on the F and K lists, and 724 on the P and U lists. These are presented in searchable tables available on EPA’s website.

Hazard codes

The hazard codes indicate the basis for the waste being included in the hazardous waste lists. These are:

• Ignitable wastes (I)
• Corrosive wastes (C)
• Reactive wastes (R)
• Toxicity characteristic wastes (E)
• Acute hazardous wastes (H)
• Toxic wastes (T)

Toxic waste (T) is different than toxicity characteristic wastes (E) because the (E) is based on a test called the Toxicity Characteristic Leaching Procedure (TCLP), while (T) is based on the presence of a toxic or hazardous constituent and poses a substantial risk. The description of this test can be found in Appendix II of 40 CFR Part 261.

For further reference, Appendix VII to Part 261 indicates hazardous constituents for which a waste was listed.