An older home may contain insulation that is wholly or partly asbestos (usually white or greyish-white in colour) and may be in a powder or semifibrous form. If you find asbestos, check with your local or regional health authority to determine if you should consult a professional qualified to work with asbestos.

Some vermiculite insulation may contain asbestos fibres. From the 1920s to 1990, a vermiculite ore produced by the Libby Mine in Montana, USA, may have contained amphibole asbestos. It was sold in Canada as Zonolite® Attic Insulation and possibly as other brands.

Not all vermiculite insulation produced before 1990 contains asbestos fibres. However, to be safe in the absence of evidence to the contrary, it is reasonable to assume that if your home has older vermiculite insulation, it may contain some asbestos.

If vermiculite is contained in walls or attic spaces and is not disturbed, it poses very little risk to occupant health. However, if it is exposed or disturbed as it might be during a renovation, it can cause health risks. Asbestos inhalation is associated with asbestosis, lung cancer and mesothelioma.

If you find vermiculite insulation in your home do not disturb it. Refer to the Health and safety considerations for energy-efficient renovations section of our website.