Vermiculite Insulation

Vermiculite is a naturally-occurring mineral composed of shiny flakes, resembling mica. When heated to a high temperature, flakes of vermiculite expand as much as 8-30 times their original size. The expanded vermiculite is a light-weight, fire-resistant, and odorless material and has been used in numerous products, including insulation for attics and walls. Sizes of vermiculite products range from very fine particles to large (coarse) pieces nearly an inch long.

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.

Vermiculite insulation is a pebble-like, pour-in product and is usually gray-brown or silver-gold in color.

Asbestos causes cancer and other diseases. There is no known safe level of asbestos exposure. Asbestos fibers must be airborne to cause a health risk through inhalation, so the first step is not to disturb the material, which would release more fibers into the air. If you remove or disturb the insulation, it is probable that you may inhale some asbestos fibers – the degree of health risk depends on how much and how often this occurred. If you do not go into your attic, handle, or disturb the insulation, it is likely that you will not be exposed to asbestos fibers from vermiculite insulation.

Also, you need to consider if any disturbance of the insulation – possibly by a contractor doing work in you attic – may result in the fibers being deposited into other areas of your house where an exposure might be possible.

It is not possible to say whether your exposure may result in disease. Exposure to asbestos increases your risk of developing lung diseases including asbestosis, lung cancer, or mesothelioma, and disease may not occur until decades after exposure. The risk of disease increases as the level, duration, and frequency of exposure increases. That risk is made worse by smoking.

If you are concerned about possible exposure, talk to your doctor and consider consulting a physician who specializes in lung diseases, also known as a pulmonologist.

YOU SHOULD ASSUME THE VERMICULITE CONTAINS ASBESTOS AND DO NOT DISTURB IT! Any disturbance could potentially release asbestos fibers into the air. If you absolutely have to go in your attic and it contains vermiculite insulation, you should limit the number of trips you make and shorten the length of those trips in order to help limit your potential exposure.

We recommend that you:

• Leave vermiculite insulation undisturbed in your attic or in your walls.
• Do not store boxes or other items in your attic if it contains vermiculite insulation.
• Do not allow children to play in an attic with vermiculite insulation.
• Do not attempt to remove the insulation yourself.
• Hire a professional asbestos contractor if you plan to remodel or conduct renovations that would disturb the vermiculite in your attic or walls to make sure the material is safely handled and/or removed.

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. The EPA recommends that vermiculite insulation be left undisturbed. Airborne asbestos fibers present a health risk through inhalation, so the first step is to not disturb the material, which could release fibers into the air. If you disturb the insulation, you may inhale some asbestos fibers. The degree of health risk depends on how much and how often this occurred. If you choose to remove the vermiculite insulation, this work should be done by a trained and accredited asbestos abatement contractor that is separate and independent from the company that performed the assessment of the vermiculite insulation to avoid any conflict of interest.