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Asbestos is a mineral fiber that can be found throughout California. It is mined just like any other mineral. These naturally occurring fibrous minerals possess high tensile strength, the ability to be woven and are resistant to heat and most chemicals, as well as being incombustible and corrosion and friction resistant. Because of these properties, asbestos fibers have been used in a wide range of building materials and manufactured goods, including roofing shingles, ceiling and floor tiles, paper and cement products, electrical and thermal insulation, textiles, coatings, and friction products such as automobile clutch, brake and transmission parts. Thermal system applications include steam or hot water pipe coverings and thermal block insulation that can be found on boilers and hot water tanks. Fireproofing insulation may be found in building structural beams and decking. Acoustical insulation (soundproofing) has commonly been applied as a troweled-on plaster in school and office building stairwells and hallways. Asbestos fibers have been incorporated into over thirty-six hundred (3600) commercial products. Serpentine rock with veins of asbestos

Frequently, asbestos fibers are mixed with materials that bind them together producing asbestos containing material (ACM).

Unfortunately, with time and exposure to damaging forces (i.e., weather conditions, chemicals, mechanical forces, etc.), many asbestos-containing materials may become crumbled, pulverized or reduced to powder, thereby releasing asbestos fibers, or they may deteriorate to the extent that they may release fibers if disturbed.


Friable vs. Non-Friable Asbestos

The U.S. Environmental Protection Agency (EPA) made this distinction when first regulating ACM under the National Emission Standards for Hazardous Air Pollutants (NESHAP) in 1973. They called the more dangerous type of ACM "friable." Friable asbestos-containing materials were officially defined as those materials containing more than 1% asbestos which could be crumbled, pulverized or reduced to powder by hand pressure when dry, using methods specified in the NESHAP rules.

The EPA called "non-friable" asbestos the generally less dangerous form of ACM, not very likely to release asbestos fibers into the air. A non-friable ACM is a material containing more than 1% asbestos but not able to be crumbled, pulverized or reduced to powder by hand pressure when dry, using the same methods. Since inhalation of asbestos fibers has been linked to the development of respiratory and other diseases, any material which is friable, or has a high probability of releasing fibers, must be handled in accordance with the Asbestos NESHAP.

When non-friable ACM is subjected to intense mechanical forces, such as those encountered during demolition or renovation, it can be crumbled, pulverized, or reduced to powder, and thereby release asbestos fibers. When non-friable materials are damaged or are likely to become damaged during such activities, they must be handled in accordance with the Asbestos NESHAP.


Asbestos and Indoor Air

The main source of asbestos in indoor air is insulation products. Buildings built in the last 50 years used a variety of materials composed of asbestos mixed with other fibers like paper, fiberglass, or synthetic fibers and a binder, usually lime or gypsum mortar. The most commonly reported material in California homes is the cottage-cheese ceiling insulation. Other common materials include vinyl floor tiles, patching compounds and textured paints, furnace, stove and pipe insulation, stove door gaskets, some roofing shingles and siding material, and parts of some pre-1979 appliances (e.g. toasters, clothes dryers, hair dryers).


When is Asbestos a Hazard?

Exposure to asbestos can occur in a variety of ways. Airborne particles can be released by eroding natural deposits. It is often detected indoors when released from building materials like insulation, ceiling and floor tiles. It may also be released into water through erosion, corrosion of asbestos/cement pipes or disintegration of asbestos roofing that finds its way into sewers. In fact, asbestos is not always an immediate hazard. Only when materials containing asbestos are disturbed or damaged does asbestos become a problem.



The World Health Organization, the federal Department of Health and Human Services, and the U.S. EPA have determined that asbestos is a human carcinogen. Scientists do not yet know with certainty how much exposure to asbestos can result in a person developing asbestos-related disease, but scientists do know that long-term exposure to relatively high concentrations of airborne asbestos is a potent cause of disease. Therefore, it is prudent to reduce environmental exposures whenever possible.

Exposure to asbestos can cause an illness known as asbestosis as well as lung cancer and a rare cancer of the lining of the lungs called mesothelioma. Exposure occurs when asbestos fibers are inhaled but the effects from exposure may not be seen for 20 to 50 years. Cigarette smoke and asbestos together significantly increase the chances of getting lung cancer. If you are concerned about possible exposure, consult a physician who specializes in lung diseases (pulmonologist).

Asbestosis -- Asbestosis is a serious, progressive, long-term non-cancer disease of the lungs. It is caused by inhaling asbestos fibers that irritate lung tissues and cause the tissues to scar. The scarring makes it hard for oxygen to get into the blood. Symptoms of asbestosis include shortness of breath and a dry, crackling sound in the lungs while inhaling. There is no effective treatment for asbestosis.

Lung Cancer -- Lung cancer causes the largest number of deaths related to asbestos exposure. People who work in the mining, milling, manufacturing of asbestos, and those who use asbestos and its products are more likely to develop lung cancer than the general population. The most common symptoms of lung cancer are coughing and a change in breathing. Other symptoms include shortness of breath, persistent chest pains, hoarseness and anemia.

Mesothelioma -- Mesothelioma is a rare form of cancer that is found in the thin lining (membrane) of the lung, chest, abdomen, and heart and almost all cases are linked to exposure to asbestos. This disease may not show up until many years after asbestos exposure. This is why great efforts are being made to prevent school children from being exposed.


Asbestos regulations

The EPA established the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Asbestos to minimize the release of fibers during activities involving asbestos handling. The District regulates asbestos demolition and renovation operations using Rule 62.7 instead of the NESHAP.

Rule 62.7 applies to all renovation and demolition operations, including those not previously regulated under NESHAP. The rule applies to operations at dwelling units and operations involving 100 or more square feet of ACM. Residential single-unit dwellings where owner/occupant performs such operations are exempt.

State and Federal regulations require that all materials must be removed during building renovations or demolition activities. Building codes today still allow asbestos containing materials (ACM) to be installed into new buildings.

Note: The Business and Professions Code sections 7180(b)(3) and 7187 prohibit:
Contractors from providing professional health and safety services or performing any asbestos risk assessment, including clearance air monitoring
Consultants and site surveillance technicians from having any financial or proprietary interest in an asbestos abatement contractor hired for the same project


EPA: Basic Information
EPA: Laws and Regulations
CDC/National Institute for Occupational Safety and Health
U.S. EPA Asbestos Ombudsman: 800-368-5888
Cal/OSHA Asbestos Consultants Unit: 916-574-2993
Asbestos Information Association: 703-412-1150

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