Vermiculite is a naturally occurring mineral composed of shiny flakes which resemble mica. When heated to high temperature, the flakes expand into a light-weight, fire-resistant, and odorless material used in numerous products, including insulation for attics and walls.
VERMICULITE INSULATION CONTAMINATION
A mine near Libby, Montana, was the source of over 70 percent of all vermiculite sold in the United States from 1919 to 1990 which also contained deposits of asbestos and therefore contaminated the vermiculite. Vermiculite from the Libby mine was sold under the brand name Zonolite. According to EPA, if you have vermiculite insulation in your home, you should assume this materials may be contaminated with asbestos. Furthermore, testing is not necessary and may not detect asbestos due to the randomness of the contamination. You should assume that all vermiculite insulation is from the Libby mine and be treated as if it contains asbestos.
WHY IS ASBESTOS A PROBLEM FOR HOME OWNERS
Asbestos causes cancer and other diseases and there is no known safe level of asbestos exposure. If Vermiculite insulation is present in your home, do not disturb it. If you do not go into your attic, handle, or disturb vermiculite insulation, it is likely that you will not be exposed to asbestos fibers.
Federal asbestos regulations do not apply to work that you perform in your own home, but EPA strongly recommends that you do not attempt to remove vermiculite insulation yourself. EPA recommends using an accredited asbestos contractor if you need to have it removed.