Asbestos is a mineral fibre. It can be positively identified only with a special type of microscope. There are several types of asbestos fibres. In the past, asbestos was added to a variety of products to strengthen them and to provide heat insulation and fire resistance.

From studies of people who were exposed to asbestos in factories and shipyards, we know that breathing high levels of asbestos fibres can lead to an increased risk of:
Lung Cancer Mesothelioma, a cancer of the lining of the chest and the abdominal cavity Asbestosis, in which the lungs become scarred with fibrous tissue The risk of lung cancer and Mesothelioma increases with the number of fibres inhaled. The risk of lung cancer from inhaling asbestos fibres 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 fibres, which can be inhaled into the lungs. The fibres 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.

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 fibres, include:
Steam Pipes, Boilers, and Furnace Ducts insulated with an asbestos blanket or asbestos paper tape. These materials may release asbestos fibres if damaged, repaired, or removed improperly.
Resilient Floor Tiles (vinyl asbestos, asphalt, and rubber), the backing on Vinyl Sheet Flooring, and Adhesive used for installing floor tile. Sanding tiles can release fibres. So may scraping or sanding the backing of sheet flooring during removal.
Cement Sheet, Mill-board, and Paper used as insulation around furnaces and wood-burning stoves. Repairing or removing appliances may release asbestos fibres. So may cutting, tearing, sanding, drilling or sawing insulation.
Door Gaskets in furnaces, wood stoves, and coal stoves. Worn seals can release asbestos fibres during use.
Sound Proofing or Decorative Material sprayed on walls and ceilings. Loose, crumbly, or water-damaged material may release fibres. So will sanding, drilling or scraping the material.
Patching and Joint Compounds for walls and ceilings, and Textures Paints. Sanding, scraping, or drilling these surfaces may release asbestos.
Asbestos Cement Roofing, Shingles, and Sidings. These products are not likely to release asbestos fibres unless sawed, drilled or cut.
Artificial Ashes and Embers sold for use in gas-fired fireplaces. Also, other older household products such as Fire-Proof Gloves, Stove-Top Pads, Ironing Board Covers, and certain Hair-dryers.
Automobile Brake Pads and Linings, Clutch Facings, and Gaskets.

Some roofing and siding shingles are made of asbestos cement.
Houses built between 1930 and 1950 may have asbestos as insulation.
Attic and wall insulation produced using vermiculite may contain asbestos fibres.
Asbestos may be present in textured paint and in patching compounds used on wall and ceiling joints.
Artificial ashes and embers sold for use in gas-fired fireplaces may contain asbestos.
Older products such as stove-top pads may have some asbestos compounds.
Walls and floors around wood-burning stoves may be protected with asbestos paper, mill-board, or cement sheets.
Asbestos is found in some vinyl floor tiles and the backing on vinyl sheet flooring and adhesives.
Hot water and steam pipes in older houses may be coated with an asbestos material or covered with an asbestos blanket or tape.
Oil and coal furnaces and door gaskets may have asbestos insulation.

If you think asbestos may be in your home, don’t panic. Usually the best thing is to leave asbestos material that is in good condition alone. Generally, material in good condition will not release asbestos fibres. Check material regularly if you suspect it may contain asbestos.
Don’t touch it, but look for signs of wear or damage such as tears, abrasions, or water damage. Damaged material may release asbestos fibres. This is particularly true if you often disturb it by hitting, rubbing, or handling it, or if it is exposed to extreme vibration or air flow. Sometimes the best way to deal with slightly damaged material is to limit access to the area and not touch or disturb it. Discard damaged or worn asbestos gloves, stove-top pads, or ironing board covers.
If asbestos material is more than slightly damaged, or if you are going to make changes in your home that might disturb it, repair or removal by a professional is needed. Before you have your house remodeled, be sure to find out whether asbestos materials are present.

The only way to be sure whether a material contains asbestos is to have it tested by a qualified laboratory. The EPA recommends testing suspect materials only if they are damaged (fraying, crumbling) or if you are planning a renovation that would disturb the suspect material. Otherwise, it is best to leave asbestos undisturbed. Samples should be taken by a properly trained and accredited asbestos professional (inspector).

Do keep activities to a minimum in any areas having damaged material that may contain asbestos.
Do take every precaution to avoid damaging asbestos material.
Do have removal and major repair done by people trained and qualified in handling asbestos. It is highly recommended that sampling and minor repair also be done by asbestos professionals.
Don’t dust, sweep, or vacuum debris that may contain asbestos.
Don’t saw, sand, scrape, or drill holes in asbestos materials.
Don’t use abrasive pads or brushes on power strippers to strip wax from asbestos flooring. Never use a power stripper on a dry floor.
Don’t sand or try to level asbestos flooring or its backing. When asbestos flooring needs replacing, install new floor covering over it, if possible.
Don’t track material that could contain asbestos through the house. If you cannot avoid walking through the area, have it cleaned with a wet mop. If the material is from a damaged area, or if a large area must be cleaned, call an asbestos professional.
Major repairs must be done only by a professional trained in methods for safely handling asbestos. Minor repairs should also be done by professionals since there is always a risk of exposure to fibres when asbestos is disturbed. Doing minor repairs yourself is not recommended since improper handling of asbestos materials can create a hazard where none existed.
Removal is usually the most expensive method and, unless required by state or local regulations, should be the last option considered in most situations. This is because removal poses the greatest risk of fibre release. However, removal may be required when remodeling or making major changes to your home that will disturb asbestos material. Also, removal may be called for if asbestos material is damaged extensively and cannot be otherwise repaired. Removal is complex and must be done only by a contractor with special training. Improper removal may actually increase the health risks to you and your family.