If your house has insulation that was installed prior to 1990, it may contain vermiculite. Vermiculite is a naturally occurring mineral that expands when heated and is perfectly safe. However, according to the U.S. Environmental Protection Agency, 70 per cent of the vermiculite used for insulation products prior to 1990 was contaminated with asbestos. For this reason, it is important that homeowners be able to identify this type of insulation and not disturb it.
Find out if the installation was installed, or replaced, in the home between the years of 1919 to 1990, which is when the contaminated insulation was manufactured. If you lived in the home or had a relative who did, try to pinpoint the date of installation. If the home had another owner, identifying the date may not be possible.
Go up into the attic, which is usually the place where most insulation is visible. Look for open areas of insulation between the floorboards. If necessary, gently pry up attic flooring with a pry bar, but do not stir up a lot of dust. Wear a dust mask while you are looking for the insulation.
Examine the insulation to see if it is white, grey, light brown or gold. Typical pink or yellow foam insulation is fine.
Examine the consistency of the insulation to see if it looks like tiny pebbles or rocks instead of foam or fluffy layers. The size of the pebbles can range from several millimetres up to 1 inch long.
If you determine that you do have vermiculite insulation, you should also assume that it is contaminated, according to the EPA.
Do not disturb, pick up or try to remove the vermiculite insulation, as it will spread the fibres through the home. Instead, stop storing items in the area, such as an attic, and avoid entering the area.