Hazardous Waste Disposal

Many facilities such as laboratories, hospitals, and schools use a variety of chemicals in small quantities (usually less than 10 gallons of each).

These small quantities of chemicals cannot be combined unless the handler is an experienced chemist with knowledge of hazardous waste codes and regulations.

The process of lab packing includes:

• Categorizing and segregating small containers of chemicals.
• Packing the lab packs into larger hazardous waste approved drums.
• Overpacking of leaking or poor quality larger drums of waste.
• Labeling and preparing the drums for transportation and disposal.
• Preparation of hazardous waste manifests.

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

Check the list of Known Hazardous and Extremely Hazardous Wastes for your material.

• If your material is listed as hazardous, use the guidelines on this page.
• If your material is listed as extremely hazardous, contact Hazardous Waste Experts.

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 – Haz Waste” sign.
Make the area easily accessible.
Note: Fume hoods may be used to temporarily store small quantities of waste materials, but should not serve as designated waste storage areas.

• 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.

• 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.

• 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 haz 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 haz waste tag.
• Organic solvents:
  • Halogenated and non-halogenated organic solvents may be mixed together in the same waste container. Contact Hazardous Waste Experts, (425) 414-3485, if you want to pour other chemical constituents in the same waste container.
  • Do not combine organic solvents with toxic metal waste!
  • Contact Hazardous Waste Experts, (425) 414-3485, 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.

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. Contact Medical Waste Experts, (887) 977-6518
  • Read How to Dispose of Sharps for details.

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

• Read How to Dispose of Empty Hazardous Materials Containers for details.

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:
  • Label it with a hazardous waste tag.
• 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
• Contact Hazardous Waste Experts, (425) 414-3485, if you need assistance with unknowns.

Request a hazardous waste collection before time or quantity limits are reached.

• Time: All haz 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 haz waste accumulates, the waste must be collected within 3 days.
• Contact Hazardous Waste Experts to request a hazardous waste collection.