Many cars on the road today contain asbestos in their clutch components. A naturally occurring family of minerals, asbestos was a popular choice for automotive parts because of its superb properties of resistance to heat and friction. Asbestos is made up of tightly-packed microscopic fibers, to which those beneficial properties are attributed.
Asbestos has been outlawed in many construction and commercial uses by the Environmental Protection Agency (EPA). It can still be used, however, in some components in which the asbestos fibers remain tightly bound, including clutch facings and linings. Although it is not often used in new parts, clutches that contain asbestos can be found in many older cars as well as in replacement components.
Asbestos is a safe material as long as its fibers are bound in the clutch facing or other component. When the part is damaged or opened, however, those fibers can escape into the air. Because they are so small, they are easily inhaled; the lungs cannot expel them, so they remain in the lungs for years, causing irritation and scarring (asbestosis). Some people can develop lung cancer or mesothelioma, a rare cancer of the lining of the lungs, as a result of prolonged exposure to asbestos. Smoking greatly increases the risk of developing these diseases.
People who manufacture automotive clutches aren’t the only ones at risk for asbestos exposure. Just through normal use, clutch materials wear down and release small amounts of asbestos dust that becomes trapped in the clutch housing. When it is opened for repair or replacement, the asbestos dust can escape and release fibers into the air. Using a compressed air hose to clean the parts, or a regular hose or shop vacuum can further contaminate the air.
Although new automotive parts are required to be labeled when they contain more than 1% asbestos, older aftermarket parts will likely not carry such labels. Assume that all clutch components contain asbestos and proceed with caution.
Because asbestos is so dangerous, there are government regulations in place for auto repair shops that perform more than five brake jobs per year. These regulations cover safe cleaning and disposal equipment that will prevent asbestos fibers from contaminating the work area or the air, including wet cleaning methods, high efficiency vacuums, workshop enclosures and disposal techniques. Even an accomplished home mechanic should not attempt clutch repair or replacement, due to the danger of asbestos contamination. If it is impossible to use a professional repair shop, the mechanic should follow the cleaning and disposal methods recommended by the EPA and the Occupational Safety and Health Administration.