Chemical Waste

All chemicals (e.g., solvents, acids, bases, and toxics) must be disposed of when they are no longer needed or wanted by the user.

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What is Hazardous Waste?

The Environmental Protection Agency (EPA) has defined hazardous waste by its general characteristics or by the material’s specific technical name. Wastes exhibiting the following characteristics are considered hazardous:

  • Ignitable – Liquids with flash points below 60oC, non-liquids that cause fire through specific conditions, ignitable compressed gases and oxidizers.
  • Corrosive – Aqueous wastes with a pH of less than or equal to 2, a pH greater than or equal to 12.5 or based on the liquids ability to corrode steel.
  • Reactive – Unstable under normal conditions, may react with water, may give off toxic gases and may be capable of detonation or explosion under normal conditions or when heated.
  • Toxic – Harmful when ingested or absorbed. Toxic wastes present a concern as they may be able to leach from waste and pollute groundwater.

Follow the links below to view complete lists of materials identified by the technical name:


Segregation and Storage

Avoid mixing different types of chemicals. If different chemical wastes are mixed together in a single container for disposal, the following segregation waste streams may be mixed together:

Segregation Group Example
Flammable/Combustible Solvents Acetone, Xylene, Methanol
Halogenated Solvents Chloroform, Methylene Chloride
Nitrogenous Hydrocarbon Trimethylamine, Diisopropylamine
Sulfurous Hydrocarbon Dimethylsulfoxide, Dimethylsulfate
Mineral Acid Hydrochloric Acid, Sulfuric Acid
Organic Acid Trichloroacetic acid, Formic Acid, Acetic Acid
Bases Calcium Oxide, Sodium Hydroxide
Aqueous solution Metal Salts, Ethidium Bromide
Oils Vacuum Pump Oil, Motor Oil

Two references for chemical compatibility and segregation can be found below:


Collection and Container Selection

Be sure to select the appropriate container for the waste stream.

  • Flammable liquids – Glass bottles, steel cans, high density plastic container
  • Concentrated acid or bases – 2.5 liter “acid” bottle. *Note: One gallon glass bottles are unacceptable for acids or bases because of the high specific gravity of the substance and thinness of one gallon glass containers increases the likelihood of container breakage
  • Aqueous solution – Glass bottles, plastic bottles, plastic cans
  • Solid waste and contaminated solid waste – Plastic air-lock bags, fiber boxes, or plastic containers
  • Broken mercury thermometers
    • Without free flowing mercury: package in the same manner as trace contaminated solid waste by labeling as waste and storing in sealed upright bag/container.
    • With mercury: glass or plastic bottle with a tight cap

Please keep in mind:

  • Containers and caps should be compatible with chemical wastes
  • Each container labeled with contents must be sealed airtight with proper screw caps (rubber stoppers, corks, and parafilm are unacceptable)
  • Fill liquid containers to NO MORE than 80% capacity to prevent spillage on top of the container
  • Top sides of the container must be clean and uncontaminated

Resource: Hazardous Waste Disposal Fact Sheet