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Vermiculite insulation can contain asbestos; these simple precautions can reduce your possibility of harmful exposure.

Many houses in London that were built before 1990 may have had vermiculite insulation, which was sold for use in attics from the 1920s to 1984, and was very popular under the CHIP program from about 1977 to the mid-1980s.

About 70% of the world supply of vermiculite came from the Libby Mine in Montana; its product was sold as Zonolite® Attic Insulation and possibly other brands in Canada during that time. This vermiculite was found to contain traces of asbestos. The amount of asbestos was very low, but it was enough to have the product taken off the market.

And unlike so many other items taken off the market, there was little that could economically be done about existing applications. Very often, the results of attempting corrective action can be worse than just living with the less than perfect product.

Asbestos can become a health problem if it is disturbed when it is in a friable state, that is when it breaks up, or can be broken up, into tiny particles that can become airborne, possibly being inhaled and lodging in the body. That is why the removal of asbestos is a major undertaking, to be carried out under strictly controlled conditions that govern how the work is done so that the asbestos is properly contained with very little possibility of anyone being contaminated by its dust. Stable and undisturbed asbestos, or asbestos that is contained so that it is not exposed to air or air currents, is normally considered safe.

If you have vermiculite in your attic and are concerned that it may contain asbestos, you can have a sample of the material tested, for a reasonable cost (around $100). Call the testing company before taking any sample to find out how much you will need, and how to safely take it. And take heart, one of the testing companies advises that very few of the samples from London that they test actually contain asbestos.

In the attic the vermiculite is normally not disturbed unless work is done such as running an electrical cable through the insulation for a ceiling light or fan, or connecting a new discharge vent from a kitchen or bathroom exhaust fan. If this is necessary, the work should be done by professionals who are aware of, and understand the necessary ways to handle this product. Care should be taken that anyone doing the work is protected by respirators of specific type (NIOSH) and not just dust masks, which are of no protection against asbestos dust.

If any vermiculite spills into the room below, never use a vacuum cleaner to pick up the spilled material! It will just blow the asbestos dust, if there is any, throughout the house. Dampen a paper towel with amended water, which is just water that has a little dishwashing detergent mixed in it to make it soak more easily into any material it touches. Its purpose is to ensure that there is no dust disturbance. Gently cover the material with the dampened paper towel and scoop it up without causing dust. Plastic bag it while wet, tie the bag securely, and place in the garbage.

The cost of removing asbestos from an attic can be very high, running into many thousands of dollars. It is much more economical to ensure that any asbestos containing material is not disturbed, and that there are no locations where it might seep out of the attic into a room below. These will be such places as where light fixtures hang from ceilings, where ventilation ducts pass through ceilings, and possibly from cracks, most likely in plaster ceilings; make sure any openings or cracks are patched or sealed with good quality caulking, and airtight. They should be airtight for other reasons - air infiltration raises energy consumption. Also, don't use your attic for storage, minimise any work that has to be done there, and use all safety precautions if work has to be done.

If after all this, you check and find that your attic insulation material does contain asbestos, and you decide that you just have to have it removed, make sure that you talk to reputable contractors qualified and certified in removing asbestos contaminated material, or you will cause yourself problems far, far worse than any that you think that you might have now. Do not be surprised if it is suggested that you move out of the house for several days while the work is done, so that work areas can be properly sealed from areas outside them. And do not be surprised if the cost of the quotation is close to the cost of buying a new car.

In the end, only you can decide if the peace of mind will be worth the cost.