Office of Research

III. Waste Categories

The following categories of radioactive wastes are generated as a byproduct of research conducted at the University. 

A.        Primary Categories

1.         Short Half-Life Waste - containing isotopes with a radiological half-life of less than 65 days.

2.         Long Half-Life Waste - containing isotopes with a radiological half-life of greater than 65 days.


B.        Waste Classification

Radioactive waste is further divided into classifications dependant on its physical/chemical properties.

1.         DAW (Dry Active Waste) - Radioactively contaminated lab trash such as glassware, paper, lab clothing, gloves, culture dishes, syringes, etc. (no free standing liquids).

2.         Liquid Waste - Aqueous or organic waste solutions containing radioactive   materials or plant tissue to include:  carcasses, excreta, organs, blood, or         tissue samples.

3.         Mixed Waste - Radioactive waste, which also contains hazardous materials / chemicals.

4.         Sealed Sources  - encapsulated radioactive sources used for instrument response checks or research.         


C.        Radioactive Waste Containers

  1. Containers for all types of radioactive waste may be obtained from the Radiation Safety Office. 
  2. Each container of waste shall bear a "Rad Tag" or sign with the radiation symbol and the words "Caution - Radioactive Material” or “Radioactive Waste".
  3. Separate waste containers will be used for short half-life and long half-life wastes.  This will help to reduce the University's waste disposal costs, since the short half-life wastes will be decayed to background and disposed of as "clean", non-radioactive waste.
  4. Radioactive wastes may be stored only in restricted areas where it can be secured against unauthorized removal.  Storage areas must be listed as an authorized place of use on the individual Authorized Investigators Radioactive Materials approval and must be posted in accordance with University posting procedures.  Radioactive waste containers may not be left unattended in a corridor. 
  5. Radioactive waste containers should be removed from the lab as soon as they are 3/4 full.  Waste container and area dose rates should be checked periodically.  Position waste containers in an area such that exposure to personnel is minimized. 
  6. If the dose rate from a waste container is greater than 2 mR/hr at 12 inches or causes the general area (measured at 3 feet) dose rate to exceed 0.5 mR/hr call the R.S.O. for a waste pickup.  If the container dose rate exceeds 2 mR/hr at 12 inches it must be located in a posted Radiation Area.
  7. Liquid waste containers are subject to breakage or leakage and should be stored so that if accidental breakage or leakage should occur, the contents will be contained in a small area, e.g., by setting it in a large pan.  Liquid containers shall have positive-fitting caps, and must be kept closed.