Vermiculite: A Hidden Health Hazard

Vermiculite: A Hidden Health Hazard

Does Your Attic Insulation Contain Vermiculite Asbestos?


Vermiculite was a popular insulation material that may contain asbestos

Vermiculite is a lightweight, fire-resistant, and odorless crystalline mineral that was popular to use as insulation for attics and walls for most of the twentieth century. These granules resemble a cross between mica and clay cat litter. They expand when heated, so the sizes of vermiculite products range from very fine particles to large, coarse pieces almost an inch long.


Unfortunately, most of the vermiculite used in North American and elsewhere came from the W.R. Grace & Company mine in Libby, Montana. The mine, which operated from 1919 – 1990, had a significant deposit of tremolite, a type of asbestos, and it contaminated the vermiculite. In fact, toxic asbestos dust from the vermiculite mines that helped the town of Libby prosper for decades is blamed for killing hundreds of area residents, and sickening thousands more.


Asbestos minerals tend to separate into microscopic particles that become airborne and are easily inhaled. People exposed to asbestos have developed several types of life-threatening diseases, including lung cancer. Like many airborne contaminants, the longer you are exposed to it, the more likely you will become sick.


Well into the 1970s, many types of building products and insulation materials used in homes contained asbestos. Bans on its use began being instituted in the U.S. in the 1970s and it was banned outright for residential uses in 1989.


Many homes in the Midwest still contain vermiculite insulation, insulating tape, older asphalt shingles, textured wall paint, old floor tiles, and other potential sources of asbestos. These can pose some risk to the indoor air quality of the home.


The good news about contaminated vermiculite is that asbestos fibers must be airborne to cause a health risk, so if you don’t disturb the material, it is unlikely you will be exposed to asbestos fibers from vermiculite insulation according to the U.S. Environmental Protection Agency. If you plan to remodel or otherwise use the space where the tainted vermiculite is located, you will need to hire a professional to remove it safely.


Home buyers can have suspicious materials tested for asbestos as part of the home inspection process. Our professional inspectors can safely gather a sample and send it for laboratory analysis, so you’ll know if your new home contains this toxic substance.

To learn more about Hawley Home Inspections’ skilled team of professional home inspectors, call or email us today at:  Certified Master Inspector


314- 257-0040

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