Joined: Dec 05, 2011
Location: Pennsylvania Pocono Mt Neutral-Acidic Elv1024ft AYR41in Zone 5b
I know many permies use vermiculite when gardening and as insulation for RMH. According to this talk it seems vermiculite is a dangerous health hazard, a toxic form of asbestos and therefore not very green. I sure many already know this.... But for those who don't....
TED Talk Margaret Hefferman: The dangers of "willful blindness" -
Joined: May 20, 2011
Location: North Georgia / Appalachian mountains , Zone 8A
Vermiculite itself is not a known health hazard, its vermiculite from a particular producer in Libby Montana which was contaminated with ASBESTOS.
Even then, its not a danger unless it gets airborne so that it can get into the lungs.
Gardeners that use vermiculite do not use it as insulation, but as an ingredient in soil mixes.
Joined: Jun 21, 2012
Location: Arkansas Ozarks zone 7 stoney acidic sandy loam
I used vermiculite briefly in the nineties...a bit in potting soil and some straight for sunflower sprouts. I didn't know where it was from/mined and learned after I finished a huge bag about possible asbestos contamination. That became another item that I decided I could easily go without. We are trying to bring in less and less from outside our land, so for me...the possible risk just reinforces a direction I wanted to go anyway.
"We're all just walking each other home."
Joined: Feb 20, 2011
Location: Moving to: NE Washington USDA zone 5 Western steppes to the Rockies
That TED talk was a huge disappointment for me. Early on, the speaker made erroneous claims, which for me, negated the legitimacy of the entire talk. Vermiculite is not a toxic form of asbestos. It is not asbestos at all.
That mine was shut down around 1990, because it was known to be contaminated. Some of the contaminated vermiculite may have been used as late as 1995 as insulation.
Concerns about Asbestos-contaminated Vermiculite Insulation
A mine near Libby, Montana, was the source of over 70 percent of all vermiculite sold in the United States from 1919 to 1990. There was also a deposit of asbestos at that mine, so the vermiculite from Libby was contaminated with asbestos. Vermiculite from Libby was used in the majority of vermiculite insulation in the United States and was often sold under the brand name Zonolite. If you have vermiculite insulation in your home, you should assume this material may be contaminated with asbestos and be aware of steps you can take to protect yourself and your family from exposure to asbestos.
It should be noted that the EPA, while stating that homes from that era might be contaminated, does not recommend that you remove it. Perhaps they feel that it is less of a danger behind your walls than it would be if exposed for removal.
There was also a mine in Virginia shut down for the same reason. Since vermiculite and asbestos are often found together, it is now required that all vermiculite mines be inspected periodically for contamination.
It is not a pretty picture, but it is not as the speaker described it.
TED gets a thumb's down from me on this one.