What is Asbestos?
Asbestos is a mineral fiber that can be positively identified only with a special type of microscope. There are several types of asbestos fibers. In the past, asbestos was added to a variety of products to strengthen them and to provide heat insulation and fire resistance. InterNACHI inspectors can supplement their knowledge with the information offered in this guide.
How Can Asbestos Affect My Health?
From studies of people who were exposed to asbestos in factories and shipyards, we know that breathing high levels of asbestos fibers can lead to an increased risk of lung cancer in the forms of mesothelioma, which is a cancer of the lining of the chest and the abdominal cavity, and asbestosis, in which the lungs become scarred with fibrous tissue.
The risk of lung cancer and mesothelioma increase with the number of fibers inhaled. The risk of lung cancer from inhaling asbestos fibers is also greater if you smoke. People who get asbestosis have usually been exposed to high levels of asbestos for a long time. The symptoms of these diseases do not usually appear until about 20 to 30 years after the first exposure to asbestos.
Most people exposed to small amounts of asbestos, as we all are in our daily lives, do not develop these health problems. However, if disturbed, asbestos material may release asbestos fibers, which can be inhaled into the lungs. The fibers can remain there for a long time, increasing the risk of disease. Asbestos material that would crumble easily if handled, or that has been sawed, scraped, or sanded into a powder, is more likely to create a health hazard.
Where Can I Find Asbestos and When Can it Be a Problem?
Most products made today do not contain asbestos. Those few products made which still contain asbestos that could be inhaled are required to be labeled as such. However, until the 1970s, many types of building products and insulation materials used in homes contained asbestos. Common products that might have contained asbestos in the past, and conditions which may release fibers, include:
steam pipes, boilers and furnace ducts insulated with an asbestos blanket or asbestos paper tape. These materials may release asbestos fibers if damaged, repaired, or removed improperly;
resilient floor tiles (vinyl asbestos, asphalt and rubber), the backing on vinyl sheet flooring, and adhesives used for installing floor tile. Sanding tiles can release fibers, and so may scraping or sanding the backing of sheet flooring during removal;
cement sheet, millboard and paper used as insulation around furnaces and wood-burning stoves. Repairing or removing appliances may release asbestos fibers, and so may cutting, tearing, sanding, drilling, or sawing insulation;
door gaskets in furnaces, wood stoves and coal stoves. Worn seals can release asbestos fibers during use;
soundproofing or decorative material sprayed on walls and ceilings. Loose, crumbly or water-damaged material may release fibers, and so will sanding, drilling or scraping the material;
patching and joint compounds for walls and ceilings, and textured paints. Sanding, scraping, or drilling these surfaces may release asbestos fibers;
asbestos cement roofing, shingles and siding. These products are not likely to release asbestos fibers unless sawed, dilled or cut;
artificial ashes and embers sold for use in gas-fired fireplaces, and other older household products, such as fireproof gloves, stove-top pads, ironing board covers and certain hairdryers; and
automobile brake pads and linings, clutch facings and gaskets.
Where Asbestos Hazards May Be Found in the Home
Some roofing and siding shingles are made of asbestos cement.
Houses built between 1930 and 1950 may have asbestos as insulation.
Asbestos may be present in textured paint and in patching c