I did a bit more research on the subject of asbestos in Vermiculite. I have now read conflicting accounts of there being a danger of it containing asbestos or that the amount of asbestos poses a danger. I do know a few things for certain, and some things not for certain and, as you will see I nonetheless was able to make up my mind on whether or not to go back to using Vermiculite:
The asbestos scare regarding commercially available vermiculite started or rose up again within the past 5 or 6 years in my area, and in Herpdom.
In that time, my local Home Depots (and many, if not all, local garden centers) stopped selling horticultural Vermiculite.
They have not started selling it again as far as I aware (at least not Home Depot as far as I know).
The government, specifically the EPA, did some studies about possible contamination of Vermiculite Insulation products and Vermiculite garden products.
There is no known minimum amount of asbestos needed to cause diseases such as cancer. In other words any minimal contact with asbestos potentially can later cause disease. Sure a one time exposure may not necessarily cause lung disease, but it may be possible if not probable.
Asbestos fibers remain in the lungs forever (as long as your forever lasts anyway).
It is unlikely that currently marketed Vermiculite contains high levels of asbestos, but it is possible. Some such products did contain small or trace amounts of asbestos as recently as 2000. The EPA did a study that found asbestos (in at least trace amounts) in 15% of the samples tested, or 8 out of 54. There was another test that found asbestos in 17 of 38 samples – a tad more than .45%. That figure alone is scary enough for me not to want to use Vermiculite but; I’ll admit I am a whimp.
I wonder if either 38 or 54 samples was a broad enough sample to perform a truly scientific test considering all of the bags of vermiculite out there. (see:
http://www.epa.gov/asbestos/vermfacts.pdf). Another study (or the same study cited in another report?) used only 38 Vermiculite products, and found asbestos in 17 of the samples! How the percentages have changed – that is asbestos in just above 45% of the samples. (see:
http://www.epa.gov/asbestos/vermiculite.pdf).
Of the testing wherein 54 samples tested, only .001 grams of vermiculite was tested from each sample and the EPA admits there may have been higher levels of vermiculite in other samples from the same bag. (see:
http://www.epa.gov/asbestos/vermiculite.pdf).
While the EPA states there is only minimal risk to the home user (in gardening and planting) it nonetheless recommends using other types of soil conditioners (again they were talking about Vermiculite for gardening applications, which is the type we buy for use with herps) such as Perlite, sawdust, peat or bark. (see:
http://www.epa.gov/asbestos/vermfacts.pdf).
As to where and when asbestos is found in Vermiculite:
“Now, as for vermiculite being contaminated with asbestos, the EPA has only found this to be true only in one mine located in Libby, Montana several years ago, and the vermiculite was found to contain trace amounts of an asbestos-like material called asbestiform.”
Asbestiform is not the only type of asbestos material found in vermiculite. There have been at least 4 types of asbestos found within Vermiculite from the Libby Mine and they are called Libby amphiboles. These are made up of: actinolite, tremolite, winchite and richterite asbestos. (
http://www.epa.gov/asbestos/insulationreport.pdf). The primary type found in vermiculite from the Libby Mine was tremolite asbestos. (se:
http://www.epa.gov/region01/homechecklist/qa.html). While Asbestiform may have been found in trace elements this is not true of tremolite asbestos which was abundant in the vermiculite.
Vermiculite Insulation has been shown to possibly contain up to 2% of asbestos (see:
http://www.epa.gov/asbestos/insulationreport.pdf). So if you used a bag of 100 grams of vermiculite, it could conceivably contain up to 2 grams of asbestos. Of course the threat is not as high now that the Libby Mine has been closed. Yet there is still a potential threat and, the threat is from asbestos mined from other than the Libby mine:
“Data shows that asbestos content in vermiculite products from other mines is lower than that of the Libby mine which closed in 1990. Therefore it is unlikely that today’s vermiculite products pose a consumer risk. Future and ongoing sample analysis will confirm or deny this assumption.”
(see:
http://www.epa.gov/asbestos/oppt.pdf).
So, note that the EPA is saying there are mines other than the Libby mine which contain Vermiculite that has asbestos in it. This indicates the threat is still out there in those other mines. They also say the threat is minimal; however in the same paragraph they say such is an assumption that will be confirmed or denied by ongoing or future testing! Great, let’s depend on future testing to say that the stuff poses a minimal threat right now!
Asbestos does not go away. It can accumulate in your home over time if you continually use products containing it, such as Vermiculite. It is known that indoor ambient levels can be increased by 50 times because of such buildup. (see:
http://www.epa.gov/asbestos/oppt.pdf)
So based on all of that good stuff, that I found over the course of the last 2 hours or so: I am not about to start using vermiculite again. My personal opinion is that no one should take the chance of asbestos contamination by using this stuff.
As to the concern over Sphagnum Moss and Sporotrichosis; I can not say I want to contract it. Late last spring I got a rash/lesions on my arms, and legs. I had been working in the garden in shorts (something unusual for me to wear). The exact things I was working with were: top soil, cow manure, and Sphagnum Peat Moss. Around the same time I also prepared eggs laying boxes and egg incubation chambers, all with long cut Sphagnum Moss. I got a very itchy rash/lesions some weeks later. They were diagnosed as some sort of fungus from working in gardens, and treated with a cream. According to a site I checked the diagnosis should have included a swab of the lesions (it was not done) and the treatment should have been with pills (also not done) but the name sounds vaguely familiar and I sure handled lots of Sphagnum Moss and Sphagnum Peat Moss. I may just have to nuke any sphagnum moss I use again in my microwave. I am not recommending anyone else do the same until I let you know if it blows up or not!
All the best,
Glenn B