Hi Ross,
Coopex dust
Toxicity to dogs and other mammals is very low. It is however quite high to insects and fish, like most insecticides.
It is 1 - 2% permethrin and the remainder is just talc.
For the dust to be dangerous to the dog (10Kg dog) it would have to ingest 15gms in a short time. Dogs hate the stuff.
One puff of the dust weighs about 50milligms. It can be placed into electrical sockets and places that the dog is not able to lick.
It was designed for control of crawling insects where sprays were not able to be used. Like electrical hazards.
I have never found any records of accidental poisoning from Coopex dust.
If you ever used Mortein or like sprays you would have ingested more permethrin from inhalation than there would be available from a couple of dustings.
If you know what LD50 means then these figures will mean something to you. The higher the value the less toxic.
Coopex dust rat.. ....1479mg/Kg
rabbit... 2000
asprin rat..... 1200
sugar rat........... 29700
table salt rat...... 3000
cadmium oxide..rat.. 72
strychnine human.... 1-2 estimated
all above values are in mgs/Kg
Taipan venom .... 25ugm/Kgm (micro grams/Kg highly toxic)
Botox (botulinum toxin) 1ngm/Kg (one nanogram /Kg)
25 ugm is an invisible dust particle or droplet. One and a half milligrams is deadly to a human. Stay clear of Taipans.
Note that asprin is more toxic than Coopex dust
To humans a 200 gm dose of asprin is often deadly.
Material Safety Data Sheet for Coopex is below.
http://garrards.com.au/images/stories/zone_files/msds/coopex_dust_msds_0908.pdf
I hope that clears up a few misconceptions. (toxicity to ants of Coopex is in the nanogram range)
Cheers