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How to Store and Dispose of Hazardous Chemical Waste

Learn how to contain, store and dispose of hazardous chemical waste at UC San Diego.

Are you in the right place? These procedures are for hazardous chemical waste only.

Follow these procedures for selecting containers and safely storing hazardous chemical waste until it is collected by Environment, Health & Safety (EH&S).

Is it "hazardous" or "extremely hazardous"?

Procedures and requirements are different for hazardous and extremely hazardous chemical waste.

Designate a hazardous waste storage area

Hazardous waste sign
  • Select an area that is:
    • Near where the waste is generated
    • Under the control of lab personnel
    • Out of the way of normal lab activities
  • Label the area with a "Danger – Hazardous Waste" sign. This sign is available upon request from EH&S Environmental Management Facility, (858) 534-2753.
  • Make the area easily accessible and recognizable to EH&S waste technicians.

Note: Fume hoods may be used to temporarily store small quantities of waste materials, but should not serve as designated waste storage areas.

Select compatible containers

  • Chemical compatibility:
    • Choose a container chemically compatible with the material it will hold. Chemicals must not react with, weaken, or dissolve the container or lid.
    • Follow these basic compatibility guidelines:
      • Acids or bases: Do not store in metal.
      • Hydrofluoric acid: Do not store in glass.
      • Gasoline (solvents): Do not store or transport in lightweight polyethylene containers such as milk jugs.
    • Read Chemical Compatibility Guidelines for more detailed information.
  • Caps and closure:
    • Use waste containers with leak-proof, screw-on caps so contents can't leak if a container tips over. Corks, parafilm, and beakers are not acceptable.
    • If necessary, transfer waste material to a container that can be securely closed. Label the new container.
    • Keep waste containers closed except when adding waste.
    • Wipe down containers prior to your scheduled collection date.
  • Size:
    • Choose appropriately sized containers. Store smaller quantities in smaller containers. It's not cost effective to dispose of 50 milliliters of material in a 4 liter container.
  • Secondary containment:
    • Always place your container in a secondary container to:
      • Capture spills and leaks from the primary container
      • Segregate incompatible hazardous wastes, such as acids and bases
    • A secondary container must be chemically compatible and able to hold 110% of the volume of waste stored in the primary container(s). Lab trays and dishpans are frequently used for secondary containment.
    • EH&S provides free secondary containers for 20-liter (5-gallon) waste containers. Request these secondary containers from the EH&S Environmental Management Facility, (858) 534-2753.

Tag every waste container

  • Attach a completed hazardous waste tag to the container before you begin using the container to accumulate and store waste.
  • Cross out all other labels on the container. Do not obliterate the original product label; waste technicians need to see what the container held before it was designated as a waste receptacle.

Liquid waste requirements

  • Do not overfill liquid waste containers. Leave a sizable amount of head space in the container to allow for expansion and safe transportation — 10% head space is a good rule of thumb.
  • Do not mix solids with liquid waste. Containers found to contain solids during processing by EH&S hazardous waste technicians will be returned to the generator for separation. See guidelines for solid chemical waste below.
  • Liquid-filled small containers such as vials and Eppendorf tubes:
    • Double-bag containers in clear plastic bags to allow visual inspection by EH&S waste technicians.
    • Containers bagged together must contain liquids or liquid mixtures with the same chemical constituents.
    • Seal each bag individually.
    • Accurately list the bag's contents and chemical constituents on the hazardous waste tag.
  • Organic solvents:
    • Halogenated and non-halogenated organic solvents may be mixed together in the same waste container. Contact the EH&S Environmental Management Facility, (858) 534-2753, if you want to pour other chemical constituents in the same waste container.
    • Do not combine organic solvents with toxic metal waste!
    • Contact the EH&S Environmental Management Facility, (858) 534-2753, if you're using toxic metal compounds. Examples of metals include arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, copper, nickel, and zinc.
  • Oils: EH&S sends waste petroleum oils to be recycled.
    • Accumulate recyclable oil separately from oils contaminated with solvents, halogens, laboratory chemicals, or fuels.
    • Oils containing traces of mercury, lead, or other regulated metals are excluded from the recycling program. Notify EH&S on the hazardous waste tag if your oil waste may contain these materials.

Dry, solid waste requirements

Chemically contaminated solid waste includes 3 categories that are packaged differently for disposal: lab trash, dry chemicals, and sharps and piercing objects.

  • Lab trash: Examples include absorbent paper products, Kim Wipes, gloves, benchcoat, and other lab supplies. Follow these guidelines:
    • Double-bag the waste in clear plastic bags to allow visual inspection by EH&S waste technicians. If contents cannot be visually inspected, EH&S cannot collect the bag.
    • Seal each bag individually.
    • Accurately list the bag's contents and chemical constituents on the hazardous waste tag.
  • Dry chemicals:
    • Dispose of solid reagent chemicals in the manufacturer's container.
    • Label the container with a hazardous waste tag.
  • Sharps and piercing objects: Sharps are items capable of puncturing, piercing, or tearing regular waste bags. Examples include pipettes, pipette tips, and broken glass. Sharps require special packaging.

Empty containers

Disposal of empty containers depends on the container size, what it is made of, and the hazardous material it once contained.

"Unknowns" or unidentified chemical waste

Unknown or unidentified chemicals are considered hazardous waste. Processing and disposal of unknowns is particulary expensive because they must be handled with great care and caution. Please make every effort to avoid "unknowns" by diligently labeling and dating inventory.

  • Once found, ask others working in the area if they know what the material is.
  • If the material can be identified:
  • If the material can't be identified:
    • Label it with a hazardous waste tag.
    • Write "Unknown" on the tag.
    • Write on the waste tag any known information. Include:
      • Type of lab that material was found in (chemistry, organic or inorganic, biology, DNA research, etc.)
      • Where the material was discovered in the lab (under a fume hood with other organics, on a shelf with inorganics or salts, etc.)
      • Age of the material
  • Request a hazardous waste collection.
  • Contact the EH&S Environmental Management Facility, (858) 534-2753, if you need assistance with unknowns.

Storage time and quantity limits

Keep UC San Diego in compliance. Request a hazardous waste collection before time or quantity limits are reached.

  • Time: All hazardous waste must be collected within 90 days from when waste is first put into containers.
  • Quantity: Up to 55 gallons of any individual hazardous waste may be stored before it must be collected.
    • When 55 gallons or more of hazardous waste accumulates, the waste must be collected within 3 days.
  • Read How to Request a Hazardous Waste Collection for details.
Questions? contact the EH&S Environmental Management Facility, (858) 534-2753.
Notice: Disposal of hazardous waste using sinks, intentional evaporation, or as regular trash is against the law. Campus laboratories must abide by strict state and federal waste disposal requirements. You may be held liable for violations of applicable laws.