Attic Insulation

By: Rob Parker, RHI, CHI, CMI

Recently I’ve done inspections in homes containing vermiculite insulation in the attics. Vermiculite is a mica-like mineral mined around the world and used in a variety of commercial and consumer products because it is fire-resistant and has good insulation qualities. The problem is that vermiculite ore, produced by the Libby Mine in Montana from the 1920′s to 1990,  known as Zonolite^® Attic Insulation and possibly other brands in Canada during that time, was the main supplier of vermiculite-based insulation to the world market and may contain amphibole asbestos.

Products made from vermiculite ore produced by the Libby Mine were not widely used after the mid-1980′s and have not been on the market in Canada since 1990. Not all vermiculite produced before 1990 contain amphibole asbestos fibres; however, to be safe and in the absence of evidence to the contrary, it is reasonable to assume that if your home has older vermiculite-based insulation, it may contain some amphibole asbestos.

Although the overall percentages of amphibole asbestos in bulk vermiculite are very low, the airborne percentages can increase if the material is disturbed. Asbestos poses health risks only when fibres are present in the air that people breathe. If asbestos fibres are enclosed or tightly bound in a product, for example in asbestos siding or asbestos floor tiles, there are no significant health risks. How exposure to asbestos can affect you depends on; the concentration of asbestos fibres in the air; how long the exposure lasted; how often you were exposed; the size of the asbestos fibres inhaled; and the amount of time since the initial exposure.

When inhaled in significant quantities, 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 best way to minimize your risk of amphibole asbestos exposure is to avoid disturbing vermiculite-based insulation in any way. If vermiculite-based insulation is contained and not exposed to the home or interior environment, it poses very little risk.

Based on current information, there is no evidence that vermiculite currently available for horticultural purposes (e.g. potting plants) is a health risk when used as directed.

If you know you have vermiculite-based insulation in your attic, take these precautionary steps.

• Do not allow children to play in an attic with open areas of vermiculite-based insulation and make sure anyone working in the attic knows about the possible presence of amphibole asbestos.
• Do not use the attic for storage if retrieving items from it may disturb the insulation.
• If you must go into the attic, walk on boards in order to minimize disturbance of the insulation and use an appropriate respirator mask. Do not remain in the attic any longer than is necessary.
• Common dust masks are not effective against asbestos fibres.
• If you have vermiculite-based insulation and you decide to have it removed, speak to trained and qualified asbestos removal professionals to handle the insulation removal. They can be found by looking up experts in “asbestos abatement /removal.
• NEVER attempt to remove the insulation yourself.
• Seal all cracks and holes in the ceilings of the rooms below the insulation (for example, apply caulking around light fixtures and the attic hatch) to prevent insulation sifting through.
• If you suspect you have vermiculite-based insulation in your walls, as a precautionary step, seal all cracks and holes.

Asbestos related illnesses are usually associated with frequent and prolonged exposure to asbestos. The time it takes to develop a disease from exposure to asbestos is usually long – up to decades. However, some steps you can take if you have concerns about exposure to asbestos are; talk to your health care provider; avoid or minimize further exposure to any form of asbestos; and stop smoking and avoid second hand tobacco smoke and other irritants that could affect your lungs.

If you are concerned that your home may contain vermiculite-based insulation you should visit the Health Canada http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/insulation-isolant-eng.php or CMHC (Canada Mortgage and Housing) http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_001.cfm websites to get the most up-to-date information as it becomes available or call 1-800-443-0395.

For specific information on safety precautions and acceptable respirator masks when working with asbestos, go to: Canadian Centre for Occupational Health and Safety (CCOHS)  Respirator page, http://www.ccohs.ca/  or call:  1-800-668-4284 (toll-free in Canada and USA)