white powder in crawl space and roof space

**andrew29** · 30th September 2007, 02:05 PM

Hi Everyone,

My partner and I have recently purchased and moved into a late 1950s double brick house in Hobart.

I've been crawling around under it and have noticed a dusting of white powder all over the place. It seems similar in texture to talcum powder and has a similar feel when you rub it between your fingers. The same stuff is in the roof cavity.

It looks as though its got there a fair while after the house was built judging by the powder free areas under bits of wood and stuff I move.

When I first saw it in the roof cavity I thought it might have been the result of someone sandblasting the roof but that doesn't make sense if its under the house as well. The other thought I had was some sort of fumigating powder?

Does anyone have any idea what it might be? And whether I should be worried about it?

Thanks,

**bugsy** · 30th September 2007, 02:26 PM

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.

**andrew29** · 30th September 2007, 05:49 PM

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

**bugsy** · 30th September 2007, 07:42 PM

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

**China** · 30th September 2007, 08:48 PM

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

**bugsy** · 30th September 2007, 09:10 PM

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.

**andrew29** · 30th September 2007, 10:08 PM

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

**bugsy** · 30th September 2007, 10:40 PM

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

**Tonyz** · 2nd October 2007, 09:44 PM

How long you been in this house?
Any Idea who the previous people living there were and
Did they have police records
Would the Drug squad still be interested in your place

**andrew29** · 12th October 2007, 09:14 PM

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!

**Bleedin Thumb** · 14th October 2007, 11:54 AM

I used to live in a flat in South Brisbane that used to be used as a brothel before we moved in - well actually we were squatting.

You ran your finger over any architrave and you got a fine white powder...everything was covered in talcum powder!

It was a hard place to live in...besides the very loud wallpaper, we used to get really creapy blokes knocking on the door at all hours of the night asking for Sheryl or Lisa!

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