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Re: C-14 Bioassay



SKI2NEWENG wrote:
> 
>      I cannot find any specific guidelines for when a Bioassay is required for
> individuals working with millicurie quantities of C-14 in a research and
> development setting ???    Is requiring a bioassay (urine or breath) within 2
> weeks when labeling proteins, etc. with greater than 20 mCi sound reasonable
> ???
> 
>   The chemical form is not Carbon Dioxide nor Carbon Monoxide...
> 
> Thanks,
> 
> GREG MORIARITY

Greg and Radsafers,

First, taking a bioassay 2 weeks after a potential intake of C-14 can be
a problem for compounds with a short biological half time, e.g. a few
hours or 1-2 days. I recommend taking a urine (and/or breath) sample
either at the end of the work day or the following morning.

Second, 20 mCi is only 10 times the ALI of 2 mCi for C-14. It is
unlikely that anyone would inhale 10% of his/her experiment! I would be
comfortable with setting the criteria for doing a bioassay somewhat
higher, say 50 or 100 mCi.

Third, I think that there are no standard guidelines for when to do
bioassays with C-14.

Best regards,
Wes
-- 
Wesley R. Van Pelt, Ph.D., CIH, CHP                KF2LG
President, Van Pelt Associates, Inc.     
Consulting in radiological health and safety.
mailto:VanPeltW@IDT.net        
http://shell.idt.net/~vanpeltw/index.html