Re: Pest Control - Additional information on Gentrol usage

[Kay Lancaster <kay@xxxxxxxx>]

On Wed, 7 Apr 2004, Sandra L. Troon wrote:
> decision that the pesticide should not be put inside the case. We
> discussed considering freeze treatment of the case contents.
>
> At this point the curator is wondering if anyone else is using this
> pesticide or one like it?  I personally have strong reservations about
> using pesticides in museums because of their potential for adverse
> effects on people, the environment, and artifacts.  Thanks for your
> answer Meg and a big hello to you.

I'm a former herbarium curator, not a textile specialist: Hydroprene
(the active ingredient of Gentrol) is an insect growth regulator (IGR)
that works by blocking development of adults from juveniles. I cannot
speak to its potential effects on artifacts if applied to them (it's
water soluble; 2g/l at 20oC), but it appears to be one of the least
toxic pesticides, and one I would be comfortable using in a herbarium
environment as a premises spray (though not on specimens) -- certainly
more comfortable than I'd be with using the more commonly used
pyrethrins and pyrethroids. (The old standard herbarium specimen
treatment was mercuric chloride and/or methyl bromide fumigation-- and
I'll take pyrethroids over that!)

LD50 for ingestion of hydroprene in rats is more than 5000mg/kg, and
more than 10,000mg/kg in dogs -- by comparison, acetominophen (Tylenol)
has an LD50 of about 1000mg/kg in rats; table salt has an LD50 of 3000
mg/kg (LD50 is the measure of an acute dose that would kill 50% of the
test population.)

A good place to look for toxicity and environmental information is at
the National Pesticide Information Center:
http://npic.orst.edu/npicfact.htm and at ExToxNet, the Extension
Toxicology Network:  http://extoxnet.orst.edu/ and Toxnet at
National Library of Medicine: http://toxnet.nlm.nih.gov

Hydroprene, depending on the formulation, rates from "caution" to
"warning", but not "danger".  Caution is the lowest hazard warning
word allowed to be used on a pesticide -- if fly swatters were classed
as pesticides, they'd have to have a "caution" label.

It appears to have a reasonably short time "residence time" in animals;
about 75% of an acute dose was gone in 2-10 days in rats. It appears to
have no predicted reproductive effects in mammals in any sort of
reasonable doses.  There are no human studies available, according to
NPIC, but ToxNet at the National Library of Medicine quotes the
1991 Farm Chemicals Handbook as saying no skin irritation and minimal
eye irritation was noted in humans occupationally exposed.
Acceptable daily intake for humans (it's allowed for use in food
handling) OPP RfD 0.02mg/kg

Freezing specimens is certainly a good option for infested items that
can be frozen, but it's not going to do much for a premises infestation
unless you can freeze the premises, too.

(Current common herbarium practice is to freeze all incoming specimens,
all specimens removed from airtight cases for more than a few minutes,
inspection and trapping, and the occasional use of premises sprays when
needed.)

Here are some more web references about museum pest control:
http://www.collectioncare.org/cci/ccipc.html
http://www.colostate.edu/Depts/IPM/natparks/museum.html
http://bss.sfsu.edu/calstudies/arttest/sum.htm
http://www.cr.nps.gov/museum/publications/conserveogram/cons_toc.html
http://www.uic.edu/sph/glakes/harts/HARTS_library/Ipm.txt

Kay Lancaster  kay@xxxxxxxx