Thanks and Further info on the Picric Acid

["Vernig, Peter G." <Peter.Vernig@med.va.gov>]

Group,
First thanks to all that responded.  Consensus seems to be that 20 grams
would have cleaned out that lab room but not caused structural damage to the
building.

I did not go into detail but I will elaborate a little now.  I had not dealt
with picric acid myself but have discussed it on occasion.  We have an
expert in spill response on contract and he was contacted prior to doing
more than evacuation of the room, that is by our procedure.  By expert I
mean he has degrees in chemistry and industrial hygiene and has been doing
this type of work for over 10 year and has all of his fingers!  Seriously he
is an expert.  I was unpleasantly surprised at the size of the explosion
likely, when I read responses from the group.  But after talking with our
consultant, I realize that picric acid is unstable in crystalline form when
it has lost it's water of hydration.  For those not fluent in chemical
terminology, water molecules that are incorporated in the crystalline
structure.  The material was a powder, it had not grown the crystals that
are characteristic of the non hydrated crystal which is very shock
sensitive.  This was discussed out of my hearing at the time.  So the main
spill responder felt comfortable in carefully adding cold water.  Our
consultant said when there is any evidence of crystal growth, he won't touch
it but calls the bomb squad.

I was assisting, mostly by observing.  Our procedure calls for two people on
any response and I was number 2.  I positioned myself to be out of the line
of a blast but realize now if there had been one I still would have been at
risk for serious injury.  One of our other responders said she still
wouldn't have touched it and would have requested the consultant respond to
add the water.  That I suppose is a judgement call.

Thanks again.  I guess my take home lesson is ask questions until you REALLY
UNDERSTAND THE SITUATION.

Peter G. Vernig
Radiation Safety Officer
VA Medical Center, Denver

1055 Clermont Street, Denver, CO 80220
ATTN:  RSO, Mail Stop 115
peter.vernig@med.va.gov
303-399-8020 ex 2447
FAX 303-393-5026

Any opinions expressed in this message are solely my own and do not
necessarily reflect the opinion or policy of the Denver VA Medical Center,
The Dept. of Veterans Affairs, or the U.S. Government.

"You win some.  You lose some.  And some get rained out."  Y. Berra

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