All chemicals (e.g., solvents, acids, bases, and toxics) must be disposed of when they are no longer needed or wanted by the user. Request a Hazardous Waste Pickup: RSS or EHS Assistant.
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:
- EPA Hazardous Waste List (approximately 500 chemicals)
- California Hazardous Waste List (approximately 800 chemicals
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
Key Points
- Ensure that containers and caps are compatible with chemical wastes.
- Chemical waste containers shall be closed when not in use.
- Chemical waste containers shall be placed in appropriate secondary containment.
- Label all chemical hazardous waste (RSS or EHSA-generated label).
- Ensure waste accumulation start date is noted.
- List chemical(s) – IUPAC nomenclature – on the tag/label. DO NOT use chemical formulae and abbreviations.
- Each container labeled with contents must be sealed airtight with proper screw caps (rubber stoppers, corks, and parafilm are unacceptable).
- It is strongly recommended that labs dispose of hazardous waste containers no more than six (6) months from the date of first waste accumulation. DO NOT store hazardous waste vessels in a lab for more than nine (9) months from the date of first waste accumulation.
- Fill liquid containers to NO MORE than 80% capacity to prevent spillage on top of the container.
- Ensure the outsides of waste containers are free of contamination.
- Do not attempt to decontaminate empty containers of Particularly Hazardous Substances (PHS).
- Containers and bottles which are decontaminated and no longer hazardous shall have the original labeling defaced, and “clean”, “decontaminated”, or “washed” should be written on the container.
- For smaller quantities of solid chemical waste, labs can generate or purchase their own containers (e.g., polyethylene zip-lock bags)
- Disposal of hazardous waste by pouring down the sink is prohibited.
Sustainability
- Donate unused chemical inventory.
- Empty bottles (e.g., solvent bottles) can be re-purposed as liquid chemical waste bottles following appropriate decontamination.
- DO NOT decontaminate bottles by allowing the residue to evaporate in a fume hood or elsewhere.
- If labs choose to utilize plastic containers for liquid chemical waste, please ensure they are manufactured from polyethylene safe material.