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Re: Phenol/ Chloroform/32p mixed waste



Mark Dater asked:

>>How do or would  you handle a mixed waste stream of pippetman tips and 
>>eppendorf tubes containing or contaminated with Phenol/Chloroform liquid and 
>>32p (created during DNA extractions). Would you satellite accumulate. Hold 
>>for decay(140days) then ship as Hazardous waste (both solid and liquid) or 
>>ship offsite within 90days as Radioactive mixed waste?
>>Another question I have is the clarification of the definition of a  " 
>>Container". Do you consider a pippetman tip (AFTER USE) a container?, or is 
>>a bag full of tips a container? Could you consider them "empty" by 
>>definition or are they in fact hazardous waste?

And Dale Boyce replied:

>Good question!  What is the current status on the regs about
>holding mixed waste?  I believe there was a suspension of the
>time limit for storing mixed waste.  Is that still in effect?
>
>I am not directly involved in chemical safety, but I understand
>EPA has an empty container exemption on disposal requirements.
>It might be a stretch to call pipette tips empty containers.
>Are there any EPA types that could comment?

With respect to hazardous waste regulations (RCRA), there are "listed"
wastes and "characteristic" wastes.  Most used phenol/CHCl3 waste will be
"characteristic" for chloroform -- which is regulated as toxic (D022) if the
chloroform is present in a liquid waste, or extractable from a solid waste,
in concentrations higher than 6.0 ppm.

To determine whether the wastes Mark mentions are RCRA Toxic for chloroform,
one might perform the procedure without the P32, and send 100g of the tips
and tubes to a local analytical lab for a Toxic Contaminate Leachate
Procedure with Zero-Headspace Extraction (TCLP-ZHE), and compare the
resulting chloroform concentration with the abovementioned 6.0 ppm.

You can pretty much bet that tubes with free liquid will have > 6.0 ppm
chloroform.

If the tips, tubes, and other trash are Toxic for chloroform, then one would
have to treat them as mixed waste when they had been used with P32, in the
example above.  This would mean, if one were to decay in storage, holding
the materials in a satellite accumulation area, with all the rights and
priviledges thereunto pertaining, for the requisite 10 half-lives, then
disposing as hazardous waste.

I submit that a modest increase in labor and materials per tube/vial would
allow one to rinse a container (say with acetone or dichloromethane) to
remove the chloroform (the RCRA ingredient) and decay the now-non-RCRA-Toxic
waste in storage without regard to satellite accum rules.  I say a modest
increase per eppie, but perhaps the cumulative effect over hundreds or
thousands of eppies would preclude this option.

Since "Container" is not specifically defined in the regs (40 CFR 261-269),
it is pretty much left up to the generator to determine, but I think the
tips are spent materials/byproducts, and the bag is the container.  It all
depends on what you think you can defend in a conference with the local
regulatory enforcement people.

Mixed waste is the next big waste managment bugaboo that two competing,
perhaps offsetting, agencies are making essentially impossible to address.
Stay tuned.

Hope this helps.

John

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