Health and Safety Advisory: Vermiculite Insulation May Contain Asbestos When the Libby Mine in Montana began production of vermiculite ore in the 1920s, the mineral was becoming well known for its fire-resistant and insulation qualities. The Libby Mine supplied the majority of the world market with vermiculite-based insulation, and sold it in Canada as Zonolite Attic Insulation, and possibly other brand names, until 1990. Today, vermiculite from the Libby Mine is known for a far less-desirable trait: it may contain asbestos, a known respiratory hazard and cancer-causing substance. For this reason it has not been widely used since the mid-1980s, and has been off the market in Canada for the past 10 years. As recently as March 2004, however, Health Canada issued a health advisory to the public, warning of the possible presence of asbestos fibres in some vermiculite insulation. These asbestos fibres, said the advisory, may pose a respiratory health risk if disturbed during maintenance, renovation or demolition. The Health Canada advisory followed national media coverage of members of a Manitoba family afflicted with mesothelioma, a rare form of cancer. The attic of the family home contained vermiculite insulation contaminated with asbestos. What you should know about the risk Not all vermiculite contains asbestos fibres. However, to be safe and in the absence of evidence to the contrary, it is reasonable to assume that if buildings have older vermiculite-based insulation, it may contain some asbestos. When inhaled, asbestos fibres can cause asbestosis (a scarring of the lungs which makes breathing difficult), mesothelioma (a rare cancer of the lining of the chest or abdominal cavity) and lung cancer. The health risk is related to the inhalation of airborne asbestos liberated by the disturbance of the insulation. There is currently no evidence of risk to health if the insulation is enclosed behind wallboards and floorboards, isolated in an attic, or otherwise kept from exposure to the interior environment. There is no evidence that vermiculite currently available for horticultural purposes (e.g., potting soil), poses any danger when used as directed. Safety precautions Do not allow children to play in an attic with open areas of vermiculite-based insulation. Make sure anyone working in the attic knows about the possible presence of asbestos. Do not use the attic for storage if retrieving items from it may disturb the insulation. Avoid disturbing vermiculite-based insulation in any way. If you must go into the attic, walk on boards in order to minimize disturbance of the insulation. Use an appropriate respirator mask (common dust masks are NOT effective against asbestos fibres). Do not remain in the attic any longer than necessary. If you have vermiculite-based insulation and decide to have it removed, have trained and qualified asbestos removal professionals handle the job. NEVER attempt to remove the insulation yourself. If you plan to remodel or renovate in a manner that would disturb the vermiculite, speak to trained, qualified asbestos removal professionals before proceeding. Seal all cracks and holes in the ceilings of the rooms below the insulation (for example, apply caulking around light fixtures, ceiling fans and the attic hatch) to prevent insulation from sifting through. Even if you suspect you have vermiculite-based insulation in your walls, as a precautionary step, seal all cracks and holes. For example, apply caulking around window and doorframes, along baseboards and around electrical outlets. The best way to minimize the risk of asbestos exposure is to avoid disturbing vermiculite-based insulation in any way. If you work in a building that may contain vermiculite insulation containing asbestos, direct your concerns to the custodian department. In leased and owned buildings, they are responsible to ensure the building is safe for occupancy, on behalf of tenant departments.
Some insurance companies will not insure homes with vermiculite insulation. As the only way to ensure there is no asbestos is by laboratory testing it can be an expensive process.
