white powder in crawl space and roof space

on first reading, i would bet it is salt under the subfloor.

but if it is in the roof as well, then it could be insecticide dust.
It can be used to dust roofs and subfloors for spiders etc


Unfortunately, there is no way to tell what sort it is.
they are all mainly permethrin based these days and you are right that they are mixed with talc power for easy flow distribution
If it is over 12 months old i doubt it is still active, but alway use you PPE whenever in a roof or sub-floor.

thanks bugsy, I figured it must be something like that.

is there anyway of identifying whether its inert by now? I spose i could catch a spider and dust it and see what happens.

seems like a drastic approach to spray a heap of insecticide everywhere so that from then on anyone needing to go into the roof or under the house has to deal with a heap of fine inhalable pesticide dust!

thanks again

Originally Posted by andrew29

thanks bugsy, I figured it must be something like that.

is there anyway of identifying whether its inert by now? I spose i could catch a spider and dust it and see what happens.

seems like a drastic approach to spray a heap of insecticide everywhere so that from then on anyone needing to go into the roof or under the house has to deal with a heap of fine inhalable pesticide dust!

thanks again

its hard to know if its still active because we dont exactly know what it is.
but the white power will be mostly talc for a carrier

andrew29, in my exprience when it has been blown all about it's because there was a infestation of fleas or the like, bugsy may be able to confirm this

Originally Posted by China

andrew29, in my exprience when it has been blown all about it's because there was a infestation of fleas or the like, bugsy may be able to confirm this

can really be for anything.
most powders are registered for just about all pests.

so i 'spose all I can do is wear overalls, gloves and a respirator whenever I'm in the roof or under the house... Surely it'd be unusual for an insecticide to be sprayed about so liberally if it was likely to stay toxic to people/pets for a long time?

I have a friend who is a chemist so maybe I'll ask them if they can test it for me. I'm a bit paranoid about crawling about in unknown insecticides when I fix up the insulation.

Thanks again for your help

Originally Posted by andrew29

so i 'spose all I can do is wear overalls, gloves and a respirator whenever I'm in the roof or under the house... Surely it'd be unusual for an insecticide to be sprayed about so liberally if it was likely to stay toxic to people/pets for a long time?

I have a friend who is a chemist so maybe I'll ask them if they can test it for me. I'm a bit paranoid about crawling about in unknown insecticides when I fix up the insulation.

Thanks again for your help

make sure you post back if he does test it

Hi guys,

OK here is what I found out.

A local pest controller told me there was a guy here in hobart that does lots of 'liberal' spraying with stuff called permathrum. Its a pyrethrum based insecticide probably used for ants and spider. A chemist friend looked it up in a toxicology report and apparently it isnt so bad and breaks down reasonably qickly. Cats don't handle it well though.

I reckon ours is no longer toxic as our cat spent a day under the house and came out white about 6 weeks ago. The cat hasn't died or showed any other illness signs. From the toxicology report the cat would have showed signs very quickly.

Thanks for all your help!