Section 3: Biological Wastes



I. Microbiological Waste

Microbiological waste can either be treated on-site in the lab or can be given to EHS for disposal. The following requirements must be met when treating biological waste in the lab.

A. Record Keeping

All lab personnel who treat and dispose of microbiological waste on site in accordance with the guidelines described below, must keep the following records.

  1. date of treatment;
  2. amount of waste treated;
  3. method/conditions of treatment;
  4. name (printed) and initials of person(s) performing treatment; and
  5. written procedure for the operation and testing of any equipment used and a written procedure for the preparation of any chemicals used in treatment.

B. Performance Monitoring

A minimum 4 log10 reduction shall be demonstrated on routine performance testing using appropriate Bacillus species biological indicators if treated waste exceeds 50 pounds in any given month. This testing needs to be performed on autoclaves that are used to treat special waste.

C. Treatment Methods

Acceptable methods of treatment of microbiological waste include:

Steam Disinfection

To allow for sufficient steam access to or penetration of the waste, the waste shall be:

  1. packaged according to the recommendations provided by the manufacturer, and
  2. loaded into the chamber so as to not exceed the capacity limits as set by the manufacturer.
  3. When subjecting waste to steam under pressure, the temperature in the chamber of the autoclave must reach at least 121C and there must be at least 15 pounds per square inch (psi) gauge pressure for at least 30 minutes.
  4. The autoclave must be operated according to the manufacturer's instructions.

Chemical Disinfection

  1. Use a chemical agent that is registered with the Environmental Protection Agency (EPA) and the Texas Department of Agriculture as a disinfectant and in accordance with the manufacturer's instructions; or
  2. Immerse the waste for not less than three minutes in:

    1. A freshly prepared solution of household chlorine bleach diluted 1:10 (volume/volume) with water; or
    2. A solution of 70% by volume 2-propanol (isopropyl alcohol).
    3. Waste that has been immersed in a liquid chemical agent must be thoroughly drained before disposal.

D. Disposal

Microbiological waste which has been treated in accordance with the methods described above can be disposed of through the regular trash as long as the following procedures are followed:

  1. Place a label on the original bag or container stating "treated in accordance with 1.136 of the TAC SWFHCRF". and
  2. Place the bag or other container into another bag or container that is a different color and is opaque, e.g., a black trash bag.

Note: If treated waste is in a liquid form it can be disposed of through the sanitary sewer if it meets the requirements of the City of Waco POTW.


II. Animal Waste Disposal

Carcasses and Body Parts of Animals

Carcasses and body parts of animals that have not been preserved must be double bagged to prevent leakage and kept frozen until pickup. Carcasses and body parts of animals that have been preserved must be separated from the preservative (refer to the chemical waste section of this manual for the disposal requirements of the preservative) and double bagged to prevent leakage.

Bedding of Animals Intentionally Exposed to Pathogens

This waste can be treated on-site in the lab as long as all the requirements listed under Microbiological Waste are followed.


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