What’s the mix up with mixed waste?

What exactly is Mixed Waste?  It can be a flammable, toxic, corrosive, or reactive. It can be a “Hazardous Waste” that also contains a radioactive isotope such as 32P, 35S, 125I, 3H or 14C.  Examples include: methanol solutions containing 3H, tritiated benzopyrene in ethyl acetate, and 32P labeled GTP in chloroform.  It can also be a radioactive material, that by itself, exhibits any of the four Hazardous Waste characteristics cited above (eg, a reactive like thorium nitrate or uranyl nitrate). 

Laboratories are encouraged to substitute non-hazardous materials into their protocols to minimize the generation of mixed waste. Laboratories should use minimal volumes of hazardous materials in protocols to minimize the production of mixed waste. Additionally, do not add aqueous waste into the mixed waste as it increases the overall volume of mixed waste. 

Some helpful tips for managing mixed wastes include:

  • Use separate containers for short half-life and long half-life.  Short half-lives is any radioactive waste with a half-life <60 day at CUMC and <90 days at MS.
  • Store mixed wastes in secondary containment in the event of a leak.
  • Mixed waste containers require both a "Caution Radioactive Materials" label (record the isotope, activity and date) and a “Hazardous Waste” label (list all hazardous chemical components, written out-no abbreviations or formulas-and the percentage of each).
  • Segregate and store mixed waste in the laboratory near the point where it was generated according to isotope and chemical compatibility.
  • When containers are 75% full, complete a radioactive waste service request and waste tracking form. Submit a pickup request http://www.ehrs.columbia.edu/rwpForm.html to the MS Radiation Safety Office or email the CUMC RSO at rsohsd@columbia.edu.
  • CUMC Radiation Safety Office: http://www.cumc.columbia.edu/dept/radsafety/ 
  • Morningside Radiation Safety Office radioactive waste policy is available at http://www.ehrs.columbia.edu/raw.html.

EH&RS/EH&S Renews Relationship with FDNY Regulators

EH&RS/EH&S has a long history of taking a proactive approach in a demanding regulatory environment.  This philosophy led to an invitation extended to the FDNY Deputy Chief Inspector to speak with Faculty and staff at the Morningside Campus.  In an open and frank discussion, he clarified the FDNY’s application of certain regulations that have been vexing researchers.  Of particular interest was the question: “Can I store a single milliliter of a flammable liquid, e.g. as part of a test kit, in a freezer not designed and designated for flammable material storage?”

The Deputy Chief responded that the regulations prohibited the storage of “any amount of flammable materials” in regular refrigerators, and that there are “no exceptions for small volumes in reagent kits”.  This rule clarification reinforces that “kits containing flammable materials” may not be stored in an ordinary refrigerator or freezer, and otherwise pose a risk of receiving an FDNY Violation Order or Notice of Violation (NOV).  What’s in your freezer?

For more Lab Fire Safety Prevention tips, check out FDN(wh)Y Me @ http://www.ehrs.columbia.edu/FDNYMe.html

Customized Training Sessions

EH&RS/EH&S recently completed Department-specific training for the Biology and Biomedical Engineering Departments on the Morningside campus.  The sessions were preceded by discussions with laboratory staff on their activities and safety concerns, enabling the presentations to be highly focussed on  peoples’ actual activities, with a minimum of generic or off-topic material.  Please contact us if there are any specific training or educational programs that we can provide for your laboratory or department


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