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Classification of Chemical Waste

A chemical waste is considered to be a hazardous waste if it is specifically listed by the EPA as a hazardous waste or if it meets any of the four hazardous characteristics below*. If a chemical waste is not on the EPA list of hazardous wastes, and does not meet any of the hazardous waste characteristics, it is a nonhazardous waste†.

Hazardous Waste Characteristics

1. Ignitable Waste

• A liquid that has a flash point of less than 140° F.
• A solid that is capable of causing fire through friction or absorption of moisture, or can undergo spontaneous chemical change that can result in vigorous and persistent burning.
• A substance that is an ignitable compressed gas or oxidizer.

2. Corrosive Waste

• An aqueous solution which has a pH less than or equal to 2 or greater than or equal to 12.5 is a corrosive waste.

3. Reactive Waste

• A material that is normally unstable or undergoes violent chemical change without detonating.
• A material that can react violently with water to form potentially explosive mixtures or can generate dangerous or possibly lethal gases (cyanide or sulfide bearing).
• A material capable of detonation or explosive reaction.

4. Toxic Waste

• A waste that contains one of the constituents in concentrations equal to or greater than the values shown in (Appendix H or Appendix I) is a toxic waste.

A chemical waste can also be classified as either a process waste or a discarded commercial chemical product (DCCP). This distinction is important when manifesting and labeling. A process waste is any waste that, by virtue of some use, process or procedure, no longer meets the manufacturer’s original product specifications. Examples of process wastes are chromatography effluents, diluted chemicals, reaction mixtures, contaminated paper, etc.   

A discarded commercial chemical product is the original (virgin) material, in the original container. Examples of DCCP are small bottles of unused or outdated chemicals from laboratories, dark rooms, or service areas.

* Most of the chemicals in the Hazardous Materials Table are EPA listed wastes or common laboratory wastes with a hazardous characteristic.

† Although a chemical waste may be nonhazardous by EPA's definition, there are additional requirements for disposal at the state and local level that are beyond the scope of this manual. If you have questions about the release of a chemical waste to the environment or the sanitary sewer, contact the ORCBS for clarification. Release of di minimis (minimal) quantities of hazardous materials from laboratory operations, such as rinsing and washing glassware is allowed.

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