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Biological Waste Disposal

Biohazardous wastes should be put into “white bags with an autoclave sign”.

Sharp Containers

Example of sharp containerAll sharp containers must be rigid, puncture resistant and leak resistant. Cardboard does not meet these requirements.

Sharp containers (Figure A.4) must be labelled with the words, “Sharps Waste”.

Figure A.4 Example of sharp container

Bag and Container Use

If the container is empty or it is not in use, lids must be kept on containers.

Sharps should be placed entirely inside the sharps container.

Bags should not be used for transporting non-biohazardous items, or covering equipment such as microscopes.

Biohazardous waste should not be removed from the bag once it has been placed in the bag.

Items that can pierce the bag should not be placed in.

Human Tissues and Biohazardous Animals

Human tissues and biohazardous animals are required to be placed in red biohazard bags which should be placed inside a leak resistant container labelled with the words “Medical Waste”.

The bags must be tagged with the date and a description of the contents when storing human tissues or biohazardous animals that are waste in a freezer.

Disposal of Ethidium Bromide Waste

Ethidium bromide (EtBr) is both an irritant and a mutagen and a frame shift mutagen, which inserts double-stranded DNA and RNA resulting in the inhibition of DNA synthesis. It may be harmful by inhalation, ingestion, or skin absorption. Eyes, skin, mucous membranes, and upper respiratory tract may be irritated by the material. Chronic effects include the possible alteration of the genetic material.

If possible, a less hazardous material or micro or semi-micro techniques should be used to minimize the generation of hazardous waste.

Ethidium bromide crystals or powder, stock solutions, gels, running buffers and contaminated labware (microfuge tubes, pipet tips, lab bench diapers, gloves, etc.) should be handled as hazardous waste. Dilute solutions of ethidium bromide (less than 0.01 mg/L) may be deactivated in the lab by pouring the dilute solution through a commercially available filter cartridge designed to sequester EtBr and disposing the filtered liquid down the drain. Used cartridges should also be handled as hazardous waste.

The following procedures apply only for chemical waste, and not medical or radioactive waste.

Preparation for waste collection and storage gels: Collect gels in clear containers that can be closed or sturdy (>4mm thick) clear bags. Double bag the gels. Seal the bags or close containers with tight sealing lids. Label the container or outer bag with a “Hazardous Waste Tag” and store in a secondary container.

Crystals, powders, and stock solutions: Label the original container or stock solution container with a “Hazardous Waste Tag” and store in a secondary container.

Contaminated labware (Dry waste): Place contaminated labware in a robust (>4mm thick) clear bag. Double bag dry waste. Red biohazard bags containing EtBr dry waste will not be accepted. Sharps must be placed in an approved sharps container before being placed in a clear bag. Seal the bags and label the outer bag with a completed “Hazardous Waste Tag”. The description should state “Ethidium Bromide Dry Waste.”

Transport and Storage

Tie-close filled waste bags before transporting them.

All closed and filled bags must be transported inside a rigid bag container and may be placed on a cart. The bag itself may not be transported in an autoclave pan, cardboard box, or on a cart. They may not be carried by hand.

Do not set or store full bags on the floor, in an autoclave pan or cardboard box. They must be inside a bag container at all times except when inside the autoclave.

Store containers of waste in a secure area such as a laboratory or autoclave room. Do not set or store them in the hallway.

Do not store waste for more than 7 days at a temperature above freezing. Dispose of the bags as soon as possible.

Do not store full sharps containers for more than 7 days at a temperature above freezing. Dispose of the full sharps containers as soon as possible.

Do not store waste, full sharps containers or human tissues and animals that are waste for more than 90 days in a freezer.

Do not compact bags of waste when placing them in a storage container.


The container should not be overfilled. The lid must fit on tightly on the container.

“Contaminated waste” bags must be used for biohazardous waste which have been autoclaved before.

Biohazard waste containers must be sanitized when soiled with waste. They must be sanitized by exposure to hot water at 180 oC for 15 seconds or exposure for 3 minutes to any of the following disinfectants: hypochlorite (i.e., bleach) solution (500 ppm available chlorine), phenolic solution (100 ppm active agent), Iodoform solution (100 ppm iodine) or quaternary ammonium solution (400 ppm active agent).

Waste or sharps waste combined with hazardous chemical waste must be disposed of as hazardous chemical waste. 

Liquid wastes should be mixed with household bleach to make a 10% bleach solution. After 30 minutes of a contact time, waste should be disposed into the laboratory sink, flushing with cool water.

Non-biohazardous Sharps Waste Disposal

What Are Sharps? 

  • Needles with or without attached syringe or tubing
  • Blades, scalpels, razors
  • Glass: broken pipettes, whole or broken Pasteur pipettes, broken vials.

Disposal Procedures

  • Do not discard sharps into the regular trash can. They can cause injury to the custodians.
  • Do not recap or clip needles.

As sharps are used or generated, place them into a sharps container. A sharps container is "a rigid puncture-resistant container which, when sealed, is leak-resistant and cannot be reopened without great difficulty". Do not use cardboard sharps containers because they leak. Use plastic or other kinds of leak-proof containers.

Place sharps into a sharps container. These containers do not have to be labelled in a specific way. When the container is nearly full, seal it and dispose of the sealed container with broken glass.

When the container is 3/4 full, it should be disposed of into the contaminated waste container. The empty sharp container can be supplied from LS/LSS.

References and sources for information from the relevant websites and documentation of different universities, NGOs and government agencies used in the preparation of this website are provided at references.