Biological Waste Disposal

Material that goes directly to the landfill may not contain pathogens and first must be decontaminated. Autoclaved bags of waste (with the biohazard symbol defaced) go to the landfill with the regular trash. If choosing to double bag, use a clear outer bag. Use bags with the biohazard symbol for handling biohazards, not for general trash disposal.

Waste Requiring Decontamination Before Disposal

1. Infectious & medical waste

Microbiological laboratory wastes such as cultures derived from clinical specimens and pathogenic microorganisms, and laboratory equipment that has come into contact with them

  • Tissues, liquid blood, and body fluids from humans
  • Tissues, liquid blood, and body fluids from an animal carrying an infectious agent that can be transmitted to humans
  • Contaminated sharps

2. Other waste materials containing:

  • Pathogens, including exotic or virulent plant and animal pathogens
  • Recombinant organisms

3. Bedding/waste from animals housed under A-BSL2 (or higher) Containment

4. Sharps

Biosafety Resources

Office of Biological Safety

UW–Madison MERI Container Pickup Request Form

Biohazard Bag Procedure

Due to a 2011 change in the interpretation of landfill regulations, the UW’s waste collection contractor will no longer able to pick up RED biohazard bags to take to the landfill.

The waste collection contractor currently considers all RED waste containers, including red medical sharps containers, to be “Medical Waste” that may still be a biohazard (even if the container has already been autoclaved).

As a result, laboratories in most UW buildings that generate biohazardous or potentially biohazardous waste in biohazard bags must use orange or clear biohazard bags, but not red biohazard bags. These bags should be autoclaved then labeled with an “OK to Trash” sticker prior to disposal in the trash.

There are a few exceptions to this procedure. Certain facilities, such as the Clinical Sciences Center, send all potentially biohazardous waste, including biohazard bags, to Madison Environmental Resourcing, Inc. (MERI) for processing as medical waste. Thus, it is acceptable for (non-sharp) biohazardous materials in these facilities to be placed into red biohazard bags because they will not ultimately end up in a landfill.

If you are unsure whether biohazardous waste in your building is picked up by MERI (for disposal as medical waste) or is picked up by Waste Management after autoclaving (for disposal in the landfill as trash), please check with your building manager.

We appreciate your patience and cooperation with this change. Contact the UW Office of Biological Safety at or 608-263-2037 with any questions.

FAQs for Biohazard Bag Procedures

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Will I have to stop using red bags for material that I send to MERI?

No. At this time, there is no change to the requirements for MERI disposal. Material collected in MERI containers is assumed to be biohazardous.

Who should I contact if I want to return unopened boxes of red autoclave bags to Fisher?

Please contact Lia Klatt of Fisher Safety: 608-217-5468,

What are some of the Fisher catalog numbers for autoclave bags that I can order?

Here are a few:

  • 14828152
  • 01-814D
  • 01-815C

I use large, red, hard-walled “sharps” containers to collect glass pipets. I am currently autoclaving these containers, afixing an “OK to Trash” sticker to them and setting them in the hallway for the custodian to remove. Is this still an acceptable practice?

No. Because these containers are red-colored, they are considered medical waste, even though they have been autoclaved and have an “OK to Trash” sticker.