Disposal of Waste (Radioactive and Solid Radioactive)

Disposing of radioactive wastes:

  • Liquid radioactive wastes soluble in water must be disposed of by pouring down the sink drain in the appropriately designated waste storage location (check with the RSO for current location) and flushing with water. Record the amount of material flushed. Be careful not to exceed the following daily limits: 1 millicurie of C14, 10 millicuries of tritium, 100 microcuries of P32 or 1 millicurie of S35.
  • Living cultures must first be autoclaved in closed containers before disposal.
  • Liquid wastes accumulated in small volumes during experiment can be stored in small glass containers (labeled radioactive and then disposed of in the radioactive sink at the end of an experiment). However, each investigator must dispose of her/his own wastes at the end of the experiment and label all containers as to isotope, amount, and investigator's name.
  • Scintillation fluid must not be poured down the sink. Scintillation vials should be put into steel barrels in the waste storage room and pertinent information added to the record.

Disposing of solid radioactive wastes:

  • It is each investigator's responsibility to dispose of all her/his own radioactive wastes at the end of an experiment. Under NO conditions should material be left in the lab, in refrigerators or freezers, or in radioisotope work rooms for extended periods of time.
  • All dry radioactive wastes containing tritium or C14 have to be placed in a special drum that will eventually be discarded in a radioactive waste disposal facility. In the interest of economy, only contaminated material should go into the drum, not regular uncontaminated trash. Be sure to separate P32 and S35 , Cr51, and P33 for storage and decay. When using H3 or C14 limit the use of bench covers or "diapers".  Radioactive contamination trays are available.

Radioactive decontamination of reusable glassware and plastics:

  • Read general directions on "How to Use Isoclean or Count-Off".
  • Make up 2% solution of Isoclean or Count-Off in water. Fill contaminated glassware with this (after liquid radioactive wastes have been removed). Cover and soak for 24 hours. Remove and rinse immediately and thoroughly in the sink.
  • Remove glassware promptly and carry out normal washing procedure.

Special Notes:

  • If heavy residue adhered to glass is not removed by 2% Isoclean Count-Off, a higher concentration should be used. A cleaning brush may help.
  • Do not allow radioactive glassware to soak in Isoclean for extended periods of time for the following reasons:
    • The glass surfaces will be etched.
    • The radioactive materials can read here.