S-35 volatility

[steven t hand <hand@wam.umd.edu>]

One of our researchers informed me that S-35 compounds such as Methionine
are volatile and that he may have people use charcoal traps to open
sources received from the vendor.

I recall this being a problem years ago (5+) but the manuafacturers
refined	the processes involved in S-35 labeling so that volatility was 
severely reduced to the point that this is not an inhalation hazard and
only possibly a minor contamination hazard.

An article in the HP Journal, volume 58 march 1990, page 355 addresses
this issue.

In the article it states that the charcoal will continue to release any
S-35 that has adsorbed onto its surface, and that the amoutn released in
only a fraction of a few percent.   I agree with the author that it
is not necessary to utilize a trap for these sources.

We do have certain limits for individuals who use over 5 mCi in the case
of S-35 to submit a urine sample (baseline and post) during 
their use as a check.

Does anyone have additional information or comment on this that I may pass
along to the user and our staff?


Thank you


steve hand
umcp
hand@wam.umd.edu