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Radioactive Waste Guidelines

Only radioactive materials that are on the PI’s permit may be discarded through EH&S.  If the material is not listed, please contact Radiation Safety. 
Radioactive wastes must be segregated by PI, isotope, and type of radioactive waste.

By PI:

Radioactive isotope usage is tracked by PI.  Therefore, in common-use rooms, radioactive wastes must be kept separated from other PI’s wastes, even if they are of the same type.

By Isotope:

  • Long-lived isotopes (ex. 3H and 14C) may be consolidated in the same collection container provided they are the same type of waste and generated under the same PI. Please consult EH&S for guidance regarding other long-lived isotopes.
  • Short-lived isotopes, including any material with a half-life less than 90 days, must be:
    • Separated from each other whenever possible.
    • Segregated from long-lived isotopes.
    • Held for decay-in-storage by the lab or EH&S.  After decay and clearance, all radioactive labels and markings must be completely defaced or removed prior to disposal in the waste collection container.

Decay-in-storage guidelines:

  • A log with collection dates, activities, and isotopes must be maintained by the lab.
  • EH&S can provide space for decay-in-storage upon request, if necessary.  Please submit a radioactive waste pickup request.
  • The minimum required storage time is 10 half-lives of the isotope being decayed. The amount of activity remaining after ten half lives is approximately 1/1000 of the original amount.
  • If more than one isotope is commingled in the waste, it must be stored for a minimum of 10 half lives of the slowest decaying component. After the waste has been stored for at least 10 half-lives, the waste must be checked for any radioactivity using the appropriate survey device at the lowest scale. The reading must be the same as the background level and all results must be recorded.

After decay, the waste will be disposed of as non-radioactive waste through EH&S. All radioactive labels must be removed or destroyed before discarding the items.  Final clearance must be completed by EH&S, please email rsoresearch@columbia.edu to request service.

By Radioactive Waste Type: 

Every effort must be made to minimize waste volumes. Accordingly, each type of radioactive waste must be separated.  Animal/biological, beta plates/96-well plates, dry solid waste, liquid scintillation vials, liquid waste must be separated from each other.  Please see the following guidelines for disposal of several common radioactive waste streams.

Animal / Biological
Beta Plates/96-well plates
Dry Solid Waste
Liquid Scintillation Vials (LSV)
Liquid Waste

  • Liquid waste may be contained in 10- or 20-liter carboys supplied by EH&S.  Additional containers, and container removal can be arranged by submitting a radioactive waste pickup request.  
  • Waste collection containers must be closed when not actively adding liquid to the container.
  • List the pH of the radioactive liquid waste on the radioactive waste label, if available.
  • Secondary containment trays must be used.
  • All chemical components, including the type of buffer, must be listed on the chemical constituents section of the radioactive waste label.
  • Hazardous Waste must not be mixed with radioactive liquid waste, whenever possible. (Examples: tritiated benzopyrene in ethyl acetate, 32P labeled GTP in chloroform, etc.)
    • There should be no generation of mixed waste without the prior notification of EH&S and the RSO.
    • Do not mix iodine waste with acids or oxidizers.
  • Only EH&S may dispose of radioactive liquid waste -- DO NOT POUR IT DOWN THE DRAIN.  Please refer to the EH&S No Drain Disposal Policy.

Smoke Detectors and Exit Signs Disposal
Please refer the EH&S Health & Safety manual section 4.5 for additional information.