Pesticide Ingredient Information/Metaldehyde

A group of Cooperative Extension departments at several universities --
Cornell, Oregon State, U. of Idaho, UC Davis, and Michigan State -- got
together and wrote, in technically correct but easier to understand
language, papers on several dozen of the most frequently encountered
ingredients of pesticides sold in the USA. This information is in a
database and web site called EXTOXNET.  The URL is:

http://ace.ace.orst.edu/info/extoxnet/pips/ghindex.html

I don't have a background in chemistry and had a terrible time
understanding many of the other information sources on pesticides and have
come to rely on this one as my first points of research.  Each PIP
(Pesticide Information Profile) contains immediate and long term toxicity
information as well as ecological effects and environemntal fate.

And, in terms of Metaldehyde, one of the first sentences in the PIP is:

All product labels must include the following statement on the front panel,
"This pesticide may be fatal to dogs or other pets if eaten. Keep pets out
of treated areas", as well as the signal word CAUTION or WARNING.

It goes on to mention under acute toxicity:
Acute toxicity: Metaldehyde is slightly to moderately toxic by ingestion,
with reported oral LD50 values of 227 to 690 mg/kg in rats, 207 mg/kg in
cats, 100 to 1000 mg/kg in dogs, 200 mg/kg in mice, 175 to 700 mg/kg in
guinea pigs, and 290 to 1250 mg/kg in rabbits [8,185]. A child died after
ingesting 3000 mg (approximately 75 to 100 mg/kg for a 30 to 40 kg child)
of metaldehyde [186].
--------
FYI, the LD50 ratings refer to the concentration in millograms per kilogram
that will rapidly 		kill 50% of a small animal population. The
lower the LD rating the more toxic is the pesticide. To give you a point of
comparison, the LD50 ratings of some other pesticides are as follows:
Diazinon = 300, Malathion = 1400, Pyrethrin = 1500, Sulfur = 5000,
Insecticidal soap = 16,900.

One of the problems with the Metaldehyde products is that they are
formulated in pellets or small particles that may be attractive to pets or
children. Most other products are sprayed and the immediate toxicity
problems most likely encountered will be a dermal LD or corrosive
(eye/lung) problem to the person who is mixing or spraying.

I'm currently teaching a class and producing a video on less toxic pest
management for employees of hardware stores and nurseries. I was also one
of the authors of a Sunset book (Western USA book publishing company) on
common sense pest control. Seems like I've spent the last two years trying
to sort this all out. If any of you have questions on this area, I'd be
happy to try and answer off-line (think this thread may be getting a bit
far afield and maybe also too USA specific.)

Regards,
Carol Moholt


                         The Bay Area Gardener <http://www.gardens.com>
                 **serving gardeners in the greater San Francisco Bay Area**
                       * email: moholt@gardens.com * phone: 650-968-4480 *
                           301 Windmill Park Lane, Mtn. View CA 94043
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