Vermiculite is a low density insultiontion which has the appearance of layers of mica separated by air gaps. ( looks like potting soil). Vermiculite is a naturally occurring mineral worldwide and makes a good insulating material.
Vermiculite is not asbestos (and vermiculite sold today does not contain asbestos) but some vermiculite deposits were contaminated with asbestos. The majority of the vermiculite used worldwide was from a mine in Libby, Montana. The mine was closed in 1990. As well as being rich in vermiculite, this mine had the misfortune of having a deposit of tremolite, a type of asbestos. When the vermiculite was extracted, some tremolite came in with the mix.
Asbestos minerals tend to separate into microscopic particles that become airborne and are easily inhaled. People exposed to asbestos in the workplace have developed several types of life-threatening diseases, including lung cancer. Workers in and around the Libby mine developed serious health problems.
Like any hazards, length and intensity of exposure are major factors in the risk of asbestos-related respiratory illness. To assess the risk of asbestos exposure at a house, a sample of the vermiculite would need to be analyzed by a lab. Since most of the vermiculite used in Canada was taken from the Libby mine, the odds are quite good that there is asbestos in the vermiculite in Canadian attics.
The good news is that we don’t live in our attics. In addition, as long as it is undisturbed, neither the asbestos fibers bound up in the vermiculite chunks nor the dust will be released into the air. The bottom line is, like most household products that may contain asbestos, and there are many, doing nothing is often the best approach. Naturally, the risk of exposure increases with the amount of time spent in the attic.
If have vermiculite in your attic, and your attic is not used for living space or storage, it is normally recommended to leave it in this state. Do not disturb it. If required work is planned that involves these areas, it is strongly recommended you have this tested first. We will extract a minimum of 3 samples and have an accredited lab conduct the analysis. If it is found to contain asbestos, or if you just assume it does, precautions should be taken. The safest approach would be to have the insulation in the affected areas removed by a qualified environmental contractor