What is asbestos?
Asbestos is a naturally occurring mineral that takes the form of hollow, microscopic fibers which are nearly indestructible. It can be densely packed into a tough, flexible and very useful material, which has been used for hundreds of years as an insulation, fireproofing, and building material.
There are three major types of asbestos used in building and industry:
- Chrysotile, or white asbestos - used as insulation, fireproofing and soundproofing.
- Amosite, or brown asbestos - used in high friction applications like brake shoes & clutches.
- Crocilodite, or blue asbestos - not as common as the other two, but the most toxic form.
About 95% of all asbestos used in the U.S. has been chrysotile, the least toxic form of asbestos.
Where is asbestos found?
Asbestos is often a component in the following materials:
- Thermal insulation
- Building ventilation systems
- Ceiling tiles
- Vinyl floor tiles
- Dry wall, dry wall tape and plaster
- Texturized paints
- Roofing shingles, felt, tar, flashing
- Decorative building materials
- Sheathing on electronics and power cables
- Automotive brake pads and clutches
Can asbestos be identified visually?
There is no way to visually identify asbestos. Many materials that contain asbestos look just the same as materials that don't. The only way to confirm that a material is asbestos is to take samples and analyze the material in a laboratory. Therefore, it is best to treat anything that looks like it may contain asbestos as if it does until it is analyzed and proven to not contain any asbestos.
When is asbestos a potential health hazard?
Asbestos that is "friable" may be crumbled, pulverized or reduced to powder in your hand when dry. Friable asbestos has the potential to release asbestos fibers that can become airborne, and potentially create a health hazard.
Asbestos that is bonded, coated, painted, covered, or otherwise protected so that it doesn't release airborne fibers does not present a health hazard.
What are some health effects that could result from exposure to airborne asbestos fibers?
- Asbestosis - a progressive, non-cancerous and irreversible scarring of the lungs that can produce shortness of breath. Typical latency period is over 20 years.
- Pleural disease - plaque deposits or a thickening of the thin tissue that separates the lungs from the other organs in the body.
- Lung cancer - cancerous tumors that have a latency period of 20 to 30 years, usually fatal.
- Mesothelioma - a cancer in the lining of the chest cavity or abdomen, very rare but always fatal.
It is important to note that most asbestos related diseases have occurred in workers who historically have had high exposures to asbestos. These exposures occurred in occupations where asbestos was mined, milled, used in primary manufacturing, and in insulation trades, such as shipbuilding. Before asbestos was known to be a serious health hazard, exposure levels to airborne asbestos in these industries may have reach over 100 fibers/cc. This is 1000 times higher than the current Occupational Health and Safety Administration (OSHA) Permissible Exposure Limit (PEL) of 0.1 fibers/cc. Workers whose only exposure to asbestos was in changing auto brake shoes containing asbestos have shown no increased incidence of any asbestos related disease.
Research has shown that smoking significantly increases the risk of lung cancer in individuals who are exposed to unsafe levels of asbestos.
What can you do to limit your exposure to asbestos?
Most buildings, especially older ones, contain some amount of asbestos. But remember, asbestos is only a potential hazard if it is damaged and friable, releasing fibers into the air we breathe.
If you come across something that appears to be friable asbestos, such as damaged insulation on a pipe, assume that it is asbestos, and notify your supervisor. Do not damage or disturb the area. A sample of the material will be taken and analyzed. If it is determined to be asbestos, it will either be removed or repaired so that it is protected and no longer releasing fibers.
If your job involves stripping or buffing floors that could be vinyl asbestos tile, this should be done infrequently, using a wet method. A soft, non-abrasive pad should be used, and the machine should be run at low speed (below 300 rpm). Do not burnish or dry-buff flooring unless it has sufficient finish so that the pad can't contact the bare floor.
To report potential asbestos containing material, contact the
Office of Environmental Health and Safety at (313) 577-1200.
Source: Holland, John P., Asbestos, Hazardous Materials Toxicology - Clinical Principles of Environmental Health, Sullivan & Krieger, 1992.