Re: Biodegradeable LS Cocktails/Summary of Responses

[Ninni Jacob <njacob@gsosun1.gso.uri.edu>]

Dear RADSAFERS:
I had promised to post the results of the above questionairre.
There were over twenty responses to the post and some interesting
discussion.

About ten persons answered the questions posed.
The results are given in CAPS below:
> 
> 
> The use of Biodegradeable Liquid scintillation cocktails is increasing due
> to the fact that they are safer both for the user and the environment.
> According to the vendors, the main features that are noteworthy are:
> 1)improved laboratory safety due to low toxicity and high flashpoint
> 2)approved disposal through the sanitary sewer system, or by incineration.
> 
> I would like to hear the thoughts and comments of RADSAFERS on this subject.
> 
> 1. Do you encourage the use of biodegradeable cocktails at your institution?
> 

EXCEPT FOR TWO THE REST SAID YES.
IN ONE INSTITUTION THE USERS HAVE TO OBTAIN A WAIVER IF THEY WANT TO USE
TOLUENE-BASED (HAZARDOUS) COCKTAILS


> 2. If so, why, and what brands of cocktails do you recommend to your users?
> 
MAINLY PACKARD AND BECKMAN.
ONE PERSON SAID HE HAD A LIST OF TWENTY DIFFERENT BRANDS THAT HIS OFFICE 
HAD CHECKED OUT.


> 3. Do you permit the sink disposal of biodegradeable cocktails to the
> regional sewer system?

EXCEPT FOR THREE, ALL THE REST SAID NO.
ONE SAID THAT THEY DO NOT ALLOW DISPOSAL OF ANY RAM IN SINKS, BUT THEY
DISPOSE AT THE LOWEST POINT OF THE  SEWER SYSTEM OF THE UNIVERSITY.

> 
> 4. If so, did you need the approval of your regional sewer sytem, and what
> documentation was provided to them?
> 
HALF YES, HALF NO
MANY OF THE CHEMICALS ARE SO NEW THAT THEY DO NOT APPEAR ON THE EPA  LIST
OR THE CHEMICAL GUIDES.
> 5. Do you set criteria for users to dispose of these cocktails?
> 
HALF YES, HALF NO

> 6. Other than dilution of the radioactivity itself to meet sewer limits,
> do you set dilution limits for the chemical?
> 
HALF YES, HALF NO

> 7. One of our researchers was concerned about the concentration of
> napthalene in one of the cocktails, especially with regard to affecting fish.
> Should this be a concern?
> The vendor claims that toxicity studies have been performed on fish and
> other microorganisms.

VARIED ANSWERS. SOME BELIEVE WHAT THE MANUFACTURERS TELL THEM, OTHERS ARE
MORE SKEPTICAL. THERE HAS BEEN SOME RESEARCH ON THIS SUBJECT.

One good reference that was cited was:

Klein R.C., Gershey, E.L.  "Biodegradeable" Liquid Scintillation
Cocktails.  Health Physics 59(4), pp.. 461-470. 1990

As you can see, there was general consensus regarding the inherent safety
of these chemicals, but there was no consensus on Sewer Disposal.
Several persons said that they felt it was relatively inexpensive to
dispose via Permafix. Incineration seemed to be the preferred method of
disposal.

We contacted  one of the manufacturers and their response was the
following:

"AS A RESPONSIBLE COMPANY, WE DO NOT ADVOCATE THE DRAIN DISPOSAL OF ANY
LIQUID SCINTILLATION COCKTAIL WASTE.  WE DO UNDERSTAND THAT SOME MUNCIPAL
AND FEDERAL AUTHORITIES MAY PERMIT SANITARY SEWER DISPOSAL FOR THESE
TYPES OF CHEMICALS UNDER CERTAIN CONDITIONS. IT IS UP TO EACH INSTITUTION
TO DETERMINE THE SUITABILITY OF THEIR SELECTED DISPOSAL METHOD IN
COMPLIANCE WITH THEIR LOCAL REGUALTORY AGENCIES AND THE INTERNAL
PHILOSOPHIES OF THEIR INSTITUTION."

For those of you who are interested and are attending the Campus Radiation
Safety Officers Conference in Victoria next week, there will be a
roundtable discussion on this topic.

Hope to see you there!!

Thanking you once again for your input,

Sincerely

Ninni Jacob
Radiation Safety Officer
University of Rhode Island/
Rhode Island Nuclear Science Center
16 Reactor Road
Narragansett,RI 02882

Phone: (401) 789-9391
Fax:   (401) 782-4201
email: njacob@gsosun1.gso.uri.edu