Older Vermiculite May Have Asbestos Fibres

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. But It’s Your Health, a joint publication of Health Canada and the Public Health Agency of Canada, cites some possible health concerns.

The world’s main supplier of vermiculite-based insulation was the Libby Mine in Montana, which produced vermiculite ore from the 1920s to 1990. Vermiculite insulation was sold in Canada, under the name Zonolite and possibly other names, during that period.

The problem is that the Libby ore may contain amphibole asbestos.

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

Asbestos poses health risks only when fibres are in the air that people breathe. If asbestos fibres are enclosed or tightly bound in a product, for example in asbestos siding or 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 time since 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.

Asbestos-related illnesses are usually associated with frequent and prolonged exposure to asbestos. It can take decades to develop a disease from exposure to asbestos.

While the overall percentage of amphibole asbestos in bulk vermiculite is very low, the airborne percentages can increase if the material is disturbed. To minimize your risk of amphibole asbestos exposure, avoid disturbing vermiculite-based insulation. As long as it is contained and not exposed to the home or interior environment, it poses very little risk.

Based on current information, there’s no evidence that vermiculite 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 precautions:

• Don’t let children 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.
• Don’t use the attic for storage if retrieving items from it may disturb the insulation. 
• If you must go into the attic, walk on boards to minimize insulation disturbance and use an appropriate respirator mask – common dust masks are not effective against asbestos fibres. Don’t stay in the attic any longer than necessary. 
• If you have vermiculite-based insulation and you decide to have it removed, have trained and qualified asbestos removal professionals handle the insulation removal. They can be found by looking up experts in “asbestos abatement/removal.” 
• Never try 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, seal all cracks and holes as a precaution. 

If you’re concerned about exposure to asbestos:

• Talk to your health-care provider 
• Avoid or minimize further exposure to any form of asbestos 
• 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, visit Health Canada’s website at www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/insulation-isolant-eng.php or the Canada Mortgage and Housing Corp. site at www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_001.cfm for the latest information, or call toll free 1-800-443-0395.

For specific information on safety precautions and acceptable respirator masks when working with asbestos, check out the Canadian Centre for Occupational Health and Safety Respirator page at www.ccohs.ca, or call 1-800-668-4284.

Rob Parker, a Registered Home Inspector with the Ontario Association of Home Inspectors and Certified Home Inspector with the American Society of Home Inspectors, does home inspections in the London area. Call him at ThamesSpec Home Inspection Service at 519-857-7101, e-mail thamespec@rogers.com or visit the website at www.thamespec-inspections.com.

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