Insulation Containing Amphibole Asbestos
It's Your Health
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The Health Risks Of Vermiculite Containing Amphibole
Minimizing Your Risk
What To Do If You Suspect You Have Been Exposed To
Need More Info?
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
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
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.
The Health Risks Of
Vermiculite Containing 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
the concentration of asbestos fibres
in the air;
how long the exposure lasted;
how often you were exposed;
the size of the asbestos fibres
the amount of time since the initial
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.
Minimizing Your Risk
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.
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
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. For
information on appropriate respirator masks, see the Need More Info?
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.
If you plan to remodel or renovate--for instance, by re-insulating your
attic--in a manner that would disturb the vermiculite, speak to professionals
who are trained and qualified to handle asbestos removal before proceeding with
the work to be done.
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. For example, apply caulking
around window and door frames, along baseboards and around electrical outlets.
What To Do If You
Suspect You Have Been Exposed To Asbestos
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. Exposure to cigarette smoke and asbestos greatly
increases your chances of developing lung cancer.
Need More Info?
For the most up-to-date information on this issue, call
For more information on asbestos, visit the following
It's Your Health article Health Risks of Asbestos
The Canada Mortgage and Housing Corporation publication on
For information on general safety tips and guidelines for
working with different types of insulation and other materials, visit:
Natural Resources Canada publication, Keeping
the Heat In, Chapter II, Part IV,
Health and Safety Considerations
For specific information on safety precautions and
acceptable respirator masks when working with asbestos, go to:
Canadian Centre for Occupational Health and Safety (CCOHS)
Tel: 1-800-668-4284 (toll-free in Canada
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:
Natural Resources Canada publication on
Product Safety Web section
Environmental Contaminants Web section
Agency for Toxic Substances and Disease Registry
For more information on the
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 1-800-267-1245
Updated: September 2009
Original : March 2004
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