Asbestos is the generic name for a variety of fibrous minerals found naturally in rock formations around the world. Because asbestos fibres are strong, durable and non-combustible, they were widely used by industry, mainly in construction and friction materials. Commercial asbestos fibres belong in two broad mineralogical groups: serpentine (chrysotile) and amphibole (tremolite, actinolyte and others).
Amphibole asbestos often contains more iron and resists acid and extremely high temperatures. Because of this, it has been heavily used in industrial furnaces and heating systems. However when inhaled, amphibole fibres stay much longer in the lungs than chrysotile fibres and they are more likely to inflict damage and cause disease, including cancer. Accordingly, amphibole asbestos has been drastically controlled and largely replaced.
Chrysotile is the only serpentine asbestos that is found in almost all asbestos-based products available today and is the main form of asbestos still mined. Chrysotile is different from the amphiboles both structurally and chemically. It is generally accepted that chrysotile asbestos is less potent and does less damage to the lungs than the amphiboles.
How much asbestos is in a product does not indicate its health risk. If the asbestos fibres are enclosed or tightly bound in a compound, there is no significant health risk. One of the main problems with asbestos came from sprayed or "friable" (easily broken up) amphibole asbestos used in buildings until the 1970s. People working in construction, maintenance or in the renovation of older buildings should be particularly careful when handling this asbestos.
Minimizing Your Risk
Construction and maintenance workers should avoid creating asbestos dust from scraping, brushing, rubbing or cutting damaged insulation. Insulation damage should be reported to the appropriate authority, such as the Occupational Health and Safety Manager. If you work in this area, determine whether asbestos is present before beginning work and take appropriate precautionary measures.
Public and commercial building owners should keep an inventory of asbestos-containing materials to inform users, authorities and contractors.
Homeowners should receive expert advice before removing materials that may contain asbestos. If you think your home may contain asbestos, check regularly for signs of wear or damage. However, you can't always tell just by looking at a material. If in doubt, have it analyzed by a qualified professional, who can be found by looking up experts in "asbestos abatement /removal".
If you must handle small amounts of damaged asbestos-containing materials, follow these steps:
Keep other people and pets away, and seal off the work area;
Wet the material to reduce dust, making sure it is not in contact with electricity;
If possible, do not cut or damage the materials further and do not break them up;
Clean the work area afterwards using a damp cloth, not a vacuum cleaner, and seal the asbestos waste and cloth in a plastic bag.
Check with your local municipality on how to dispose of asbestos-containing waste;
Wear appropriate protective clothing, including a single-use respirator approved by the National Institute for Occupational Safety and Health (NIOSH);
and Wash or dispose of clothing and shower after finishing the job.
Government of Canada's Role
Health Canada has encouraged provincial occupational health authorities to adopt stringent workplace exposure limits for asbestos. The sale of pure asbestos and certain high risk consumer products that are composed of or contain asbestos fibres is strictly regulated under the Hazardous Products Act. In addition, the emissions of asbestos into the environment from mining and milling operations are subject to the Canadian Environmental Protection Act.