Vermiculite is a material used as loose fill insulation in attics and is also a component in potting soil. Prior to 1990, most vermiculite came from a mine in Montana. The mine contained asbestos, which contaminated the vermiculite. Inhaling asbestos fibres can cause lung disease or cancer. Current testing practices for asbestos contamination in vermiculite are not always accurate. Because of the danger associated with pesticide exposure and inaccuracy of testing, caution should be used around all vermiculite.
Put on a long-sleeved shirt, long trousers and boots. Wear the disposable protective clothing over your clothes and put on an N-, P- or R-100 respirator.
Take samples of the vermiculite. Grab pieces of vermiculite from several different areas to get a more accurate sample. Not all of the pieces necessarily contain asbestos. Take samples from vermiculite that has fallen to the ground and samples from high and low areas in the attic if you are testing insulation. Disturb the vermiculite insulation as little as possible to avoid releasing asbestos fibres into the air. Place the samples inside a sealed baggie.
Take off your disposable protective clothes and put them in a bin bag. Tie the bag and throw it away outside. Throw the respirator away if it is a disposable model. If it is not disposable, place it in a sealed baggie and store in it the garage out of reach of children.
Send the vermiculite samples to an asbestos testing lab using the method recommended by the laboratory.
Sample collection of vermiculite should be done by a professional. If you decide to remove vermiculite insulation from your attic, have it done by a professional who has the required equipment necessary to capture asbestos fibres.