Subject: Re: Collecting tips

From: Ron Royer <[email-masked]>
Date: Fri, 7 Apr 1995 10:17:03 -0500

Pehling and Covell suggest PDB (paradichlorbenzene) without noting that it
is now recognized to be a potent carcinogen. I personally wouldn't want to
be slogging around a field camp in PDB soup, mould or none!

**********************************************************************
Ronald A. Royer
Division of Science
Minot State University, Minot ND 58707
701-857-3209 (Personal Office), 3161 (Division Office)
701-839-6933 (FAX), <[email-masked]>
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From: [email-masked] (W. Donald Fattig)
Date: Sat, 08 Apr 1995 18:26:40 -0600

> be slogging around a field camp in PDB soup, mould or none!

The NIOSH Pocket Guide to Hazardous chemicals *does* indicate that
p-dichlorobenzene *is* a NIOSH carcinogen (in animals, at 1000ppm), and it
recommends use of a Self Contained Breathing Apparatus (Face) or Supplied
Air Respirator when using it at any concentration.  However, OSHA has
established a permissible exposure level of 75 ppm (as a time-weighted
average) or short-term exposure level of 110 ppm.  The latter levels are
without consideration of personal protective equipment (PPE) such as
respirators.

Use of a few hundred grams of this substance in a well-ventilated space
without protection is probably a minimal hazard, especially if it winds up
in sealed tins or collecting cases. but one would not want to be in "PDB
soup" at any time, anywhere.  It is a risky substance with inhalation,
ingestion, and contact routes of entry.

I have used p-dichlorobenzene in small tins in insect collecting cases for
preservation.  In my career I have also mouth pipetted E. coli, stained
electrophoretic gels with benzidine (a REAL carcinogen with no established
safe level), mutagenized fruit flies with ethylmethanesulfonate, done
paper chromatography with a variety of NIOSH-listed solvents (including
benzene, OSHA PEL = 1 ppm; NIOSH REL [Recommended Exposure Level] =
0.1ppm) , and have handled plenty of formaldehyde-soaked specimens (OSHA
PEL = 0.75ppm)!

We should be aware of risks and take conservative precautions when we are
fortunate enough to know a priori that they are risks. On the optimistic
side, it is worth remembering that the human who holds the record for the
highest measured DDT and DDE levels in his fat tissue was a freshwater
commercial fisherman - who died at the age of 100!

Don Fattig, Ph. D.
Certified Hazardous Waste Worker

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From: Christopher Wood <[email-masked]>
Date: Fri, 7 Apr 1995 20:42:57 -0700

Please ignore name in header.  This message is from:
Rod Crawford, Burke Museum, University of Washington.

> be slogging around a field camp in PDB soup, mould or none!

That's putting it a bit strong.  In the USA, PDB is so recognized only by 
the state of California, not by the federal FDA.  So far as I know 
(someone correct me if I'm wrong) the evidence is confined to lab animals 
and there is nothing linking PDB to human cancer cases.  Personally, it 
doesn't worry me as much as the prospect of a life's work destroyed by 
dermestids.  And what is the betting that Vapona (the only widely 
used alternative chemical) is not just as likely to prove carcinogenic?

Rod Crawford
[email-masked]