Texas Tech University

Biological Waste Management

Biological waste treatment and disposal depends on the state of the materials (liquids or solids). First, what is classified as biological waste? Biological waste includes: 

  • animal waste (carcasses, body parts/fluids and bedding of animals intentionally exposed to potential pathogens)
  • animal cell cultures
  • human and non-human primate blood/body parts/cultures
  • microbiological waste (cultures, stocks, specimens, transfer devices, etc.)
  • pathological waste
  • sharps as these terms are defined in 25 TAC §1.132
  • any enriched sample/specimen
  • samples/specimens that are reasonably considered to contain, have be purposefully exposed to or tested positive for a pathogen.

Biological waste should not be mixed with other non-biowaste items such as gloves, paper towels, and other regular municipal trash items. Ensuring proper segregation of biowaste materials from regular trash not only decreases the work load for work area personnel (i.e., the waste generators) but also decreases overall cost to the university for waste disposal.

Accumulation & Treatment

No matter what materials are being treated, each treatment must be logged and the records maintained for three years. Treatment logs with all required information are listed in the Biological Waste Resources section at the end of this article.

Treating Liquids

Liquid biological waste includes cell cultures, contaminated medias or supernatents from spinning down cell cultures. Follow this process to treat liquid biowaste.

  1. Prepare a fresh 10% percent bleach solution. Note that Clorox bleach is the only EPA approved bleach. 
  2. Add the bleach solution in equal volume to your liquid biowaste. For example, if you have one liter (1L) of culture, add one liter (1L) of 10% bleach.
  3. Allow the mixture to sit for at least 10 minutes to allow adequate disinfection.
  4. Pour the waste-bleach mixture down the sink and flush with copious amount of water. 
  5. Log the treatment on your Treatment Log.

Liquid Biowaste Treatment Process

Autoclaving Solids

Waste Containers

  • Waste is to be collected in leak-proof containers. Bags with the Solid biowaste containersuniversal biohazard symbol must be used to collect solid waste. If you steam-sterilize your waste, make sure your bags are autoclavable.
  • Other than benchtop collection, biohazard bags must be contained in a solid, leak-proof container with a lid capable of decontamination. The container must be marked with the biohazard symbol.

Preparing for the Autoclave

  1. Prepare waste to allow steam circulation (i.e., loosely tie bags, loosen lids or loosely cover with foil). Apply autoclave tape.
  2. If you have to transport waste through common areas, use a closable tub w/ locking lid; take the autoclave tub(s) with you.
  3. At the autoclave, place waste in a leak-proof, autoclavable tub. Do not overload the tub.

Transporting waste to the autoclave requires a tub and sign

Autoclaving and Final Disposal

  1. Autoclave waste no less than 30 minutes at 121°C and 15psi pressure.
  2. After autoclaving, Record the run in the log, carefully remove the load, and affix a "treated" sticker to biobags.
  3. Place the biobag in a black trash bag.
  4. Lab personnel can then discard waste in the dumpster.
  5. Log the treatment on your Treatment Log.

Solid biowaste autoclave treament process

Chemically Disinfecting Solids

Some solid biowaste can be chemically disinfected using a 10% bleach (or other appropriate disinfectant) upon creation of the waste. An example of this is contaminated serological pipets generated inside a Biosafety Cabinet during research. Follow the steps below. 

  1. Prepare a fresh 10% percent bleach solution. Note that Clorox bleach is the only EPA approved bleach.
  2. Submerge tips and pipettes in the bleach solution. Draw the solution into each unit as you add it to the bleach bath to ensure contact with all surfaces. 
  3. Let the mixture sit for at least minutes. 
  4. Drain the disinfectant from each unit and dispose of the regular trash. 
  5. Log the treatment on your Treatment Log.

 Solid biowaste chemical disinfection

EHS Biobarrels

Some work areas use BioBarrels provided by EHS to collect solid biological waste. BioBarrels are only provided to work areas who do not have access to a functioning autoclave for solid waste treatment. Other work areas generating biological waste must treat their waste using one of the methods described in the previous section. Certain rules must be followed when using BioBarrels. 

  • Do not place liquids in BioBarrels. Liquid biowaste should be treated by work area personnel. 
  • Do not overfill the barrels. Only fill up to 3/4 full or exceed 50 pounds per barrel. 
  • Do not place loose materials in the barrel. Biowaste should be accumulated in smaller biobags, tied off and then collected in the BioBarrel. See the image below for an example.

Biobarrel accumulation

  • BioBarrel liners must be secured tied by work area personnel and the lid snapped securely in place prior to EHS pick up. EHS will not collect improperly prepared barrels. 

Biological Waste Resources

Chemical Disinfection of Biological Waste

Chemical Disinfection Log - Liquids

Chemical Disinfection Log - Solids

Chemically Disinfecting Biowaste Poster - 11" x 17"

Autoclaving Biological Waste SOP

Autoclave Log

Autoclaving Biowaste Poster - 11" x 17"

EHS Biobarrel Preparation Poster - 11" x 17"