It's Your Health
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Some vermiculite insulation may contain amphibole asbestos fibres. These products can cause health risks if disturbed during maintenance, renovation or demolition. However, there is currently no evidence of risk to your health if the insulation is sealed behind wallboards and floorboards, isolated in an attic, or otherwise kept from exposure to the interior environment.
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. Of concern is vermiculite ore produced by the Libby Mine in Montana from the 1920's to 1990. It was sold as Zonolite« Attic Insulation and possibly other brands in Canada during that time. Vermiculite from the Libby Mine may contain amphibole asbestos. The Libby Mine supplied the majority of the world market in vermiculite-based insulation.
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 contains amphibole asbestos fibres. However, to be safe and in the absence of evidence to the contrary, it is reasonable to assume that if your building 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:
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 link between exposure to asbestos and other types of cancers is less clear.
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.
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.
If you are concerned that your home may contain vermiculite-based insulation visit the Need More Info? section in this article or the Health Canada Web site to get the most up-to-date information as it becomes available.
If you know you have vermiculite-based insulation in your attic, take these precautionary steps.
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:
For the most up-to-date information on this issue, call 1-800-443-0395
For more information on asbestos, visit the following sites:
For information on general safety tips and guidelines for working with different types of insulation and other materials, visit:
For specific information on safety precautions and acceptable respirator masks when working with asbestos, go to:
For more information on workplace safety, visit the Environment and Workplace Health, Occupational Health and Safety Web section
For more information on vermiculite and asbestos visit, the following Web sites:
For more information on the Hazardous Products Act) and asbestos, see Justice Canada's Web site
For more photographs of vermiculite insulation and additional information regarding vermiculite containing asbestos, please visit the US EPA's Asbestos Home Page
For additional articles on health and safety issues go to the It's Your Health Web section
You can also call toll free at 1-866-225-0709 or TTY at 1-800-465-7735
Updated: September 2009
Original : March 2004
ęHer Majesty the Queen in Right of Canada, represented by the Minister of Health, 2009