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Re: Use of Biodegradable LSC Cocktails
At 09:10 07.03.97 -0600, you wrote:
>Regarding "biodegradable" LSC cocktails, the answer to Sue's questions are:
>1. We do not encourage, in fact, discourage use of these cocktails.
>2. This is because there has NOT been any good research on them to
>show they are okay in the environment.
>3. We do not permit sink disposal of biodegradable cocktails.
>4. Yes, we do need permission from our regional (state and city)
>agencies to dispose any radioactive or hazardous material down the drain,
>very informal, but must have their "informed consent", so to speak.
>5. Criteria for disposal is like with all other rad waste, tag it,
>contain it properly, request pickup, we pick it up, we dispose.
>6. Only the limits required for sewer or for the vendor (drum, DOT,
>etc. limits) are necessary for this waste to be disposed. We dispose
>through Permafix, very cheap, very safe, very compliant.
>7. We also were told there was some research done, and when we
>examined it, it was inadequate, grossly so. (If I take a fish and put it
>in a solution of these cocktails, and he doesn't die quickly, is that a
>good study? Not in our opinion!) We had our toxicologists look at these
>cocktails, and they recommended against using them. There are chemicals in
>them that are not proven to be safe for people, animals or the environment.
>As stated with the mercury, many are hazardous or toxic.
>Finally, to respond to Wes Van Pelt's question about diluting the 42 ppb of
>Hg with water, that is typically not legal as a disposal management method
>for chemicals. In fact, mercury itself is very strictly regulated by EPA
>AND by state and local agencies, which are often more restrictive than the
>Federal limit. The EPA limit is 200 ppb, but our local POTW has a limit of
>5 ppb. I highly recommend that you investigate your area limits before
>beginning or continuing sewer disposal of the "biodegradable" cocktails.
>Considering disposal through Permafix is so terribly cheap, why do
>otherwise? Yes, it is easier in some ways to dispose in the sewer, but I
>have not yet heard a good enough reason for us to change our method of
>shipping out, whole vial intact, in drums.
>Sue, I posted here because some of these things are of general interest.
>If I have erred, I am sure you will all let me know! <grin>
>Hope you all have a great weekend.
>Kristin Erickson, Radiation Safety Officer
>Office of Radiation, Chemical and Biological Safety
>C124 Research Complex- Engineering
>Michigan State University
>East Lansing, Michigan 48824
>517 355-5008 Fax 517 353-4871
Kristin and fellow LSC-radsafers,
We work in the low- or even ultra-low-level liquid scintillation
spectrometry business. We chose our cocktails exclusively according to their
properties in achieving the minimum LLD. Of course we can take it easy,
because we dispose of all our LSC-vials by sending it to the Research Centre
Seibersdorf, which has an incineration plant for low-level waste. Any
scintillation vials are accepted, whether the solvent is
di-isopropyl-naphthalene or toluene, because it will yield CO2 and H2O on
burning anyway. This is cheaper than sorting out the vials according to the
cocktail. Empting the vials, washing them and disposing of the washed vials
will be much more expensive. We send it as low-level waste, even though it
could be disposed of as normal waste (we have such low levels of
radionuclides even in our standards). The reason is simple - normal waste
disposal would be more expensive..... Since we use exclusively polyethylene
vials the energy balance is positive and so we help the incineration plant
to save energy. I have proposed that we should be paid for providing this
excess energy, but the plant unfortunately does not go with it.......
I am not too familiar with these questions, but it seems to me that the
solvents may be biodegradable, but maybe the fluors still might be toxic. I
think one should contact the companies producing these cocktails and one
should be extremely careful not to violate state legislation. Any company
proposing the sewage system disposal should be held responsible for it.