Introduction to Asbestos
Asbestos is not a single substance, but a group of silicate minerals that are highly fibrous. The fibers, which are too small to be visible, are heat resistant and strong and flexible enough to be woven. The durability of the fibers becomes a problem when they get into lung tissue, where they can remain for a long time.
Asbestos is categorized by the Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) into two general types, amphibole and chrysotile, which contain in total, six asbestos minerals. Chrysotile is a single mineral, while there are five amphibole minerals. According to some studies, amphibole fibers, which are more brittle, stay longer in the lungs than chrysotile fibers, and this may explain why amphibole fibers are more toxic.
How Do People Come in Contact with Asbestos?
Most people who have developed asbestos-related illnesses were exposed to asbestos at work. Jobs in which asbestos may be encountered are found in many areas including mining, construction, automotive repair, manufacturing, shipyards, steel mills, power plants, etc. However, asbestos is a naturally occurring mineral, and when found in nature, is referred to as naturally occurring asbestos (NOA). NOA is typically found in certain rock formations. Undisturbed NOA does not pose a health threat. But natural weathering processes or human activity can disturb the NOA, releasing it into the air, where it can pose a threat.
In addition, there may be asbestos in and around buildings, including homes, on account of a variety of products. The fact is that many building and insulation products used in the construction of homes up to the 1970s contained asbestos. Asbestos is still used in some products today, although they must be labeled if the asbestos could potentially be inhaled.
The areas in which asbestos can be found include some types of:
Furnace ducts, steam pipes, and boilers may be insulated using an "asbestos blanket" or paper tape made with asbestos. Door gaskets for furnaces, and both wood and coal stoves can contain asbestos. Material used to insulate the area around woodburning stoves and furnaces may contain asbestos as well. Between 1930 and 1950, a number of houses were built with asbestos insulation.
• Roofing/Siding material
Asbestos cement may have been used for roofing, shingles, and siding
• Wall & Ceiling Materials
Soundproofing and textured paint used on ceilings and walls can contain asbestos, as may patching and joint compounds. The presence of asbestos in textured paint and patching compound was banned in 1977.
• Flooring Materials
Floor tiles themselves, as well as backing on vinyl sheet flooring, and adhesives used for installation can all contain asbestos.
• Automobile parts
Clutch facings, brake pads, brake linings, and gaskets may all contain asbestos.
• Other Products
Some older products with insulating properties, such as fireproof gloves, ironing board covers, stove-top pads, and some hairdryers contained asbestos. Artificial embers and ashes, used to make gas-fired fireplaces look like real wood fires, may have asbestos as an ingredient.
Health and Asbestos
Breathing asbestos fibers in high levels can create increased risk for lung cancer, another cancer called mesothelioma, and asbestosis. The greater the number of fibers inhaled, the higher the risk for the cancers. Asbestosis is generally associated with both high level of exposure and long-term exposure. The symptoms of any of the three may not appear for 20 to 30 years after the initial exposure.
The presence of asbestos and the normal daily exposure in small amounts are not causes of these health problems, as long as the asbestos remains intact (that is, not deteriorating and releasing fibers).
Asbestos Testing and Removal
The Environmental Protection Agency (EPA) recommends that you do not test for asbestos yourself, because the act of testing may itself cause a safety hazard if asbestos fibers are released into the air or onto the tester. EPA also recommends that homeowners not do their own repairs, whether major or minor, but hire a professional.
For questions about products that may contain asbestos, call the United States Consumer Product Safety Commission (CPSC) hotline at:
For information on inspection and control of asbestos, call your state or local health department or the regional EPA office Asbestos Coordinator. A list of local contacts can be found at the EPA website.
Written by Mary Elizabeth