Document QM4yZp0vDL8kJYBd9abXnkgQv

Page Two Sales Department Letter #76-46 November 4, 1976 Jhere are several different types of asbestos, and the type commonly used in friction materials is known as "chrysotile". This asbestos material is widely used Jin, high temperature applications because of its thermal' stability. The asbestos content in friction materials i:" may vary between 25% and 60% by weight, dependentvupon the friction material specifications. The cause of friction lining wear for the ikjst part-is not due to abrasion, but rather due to minute spot areas of intense heat at points of contact between- the drum and friction lining. At these high temperajbires ? Jthe chrysotile asbestos breaks down into harijaless tninerals, so the actual amount of asbestos fibdtJthat ,18 'liberated to atmosphere during the life of thej lining >is less than 0.3%. Exposure to high temperatures,' Essentially destroys the asbestos fibers, and tfe^4Se^-i|eJjrianical rubbing action produces a powder form with, a particle size of less than 1 micron (micrometer)! This is considerably smaller than the 5 micrpp limit specified by both OSHA and EPA, plus the fadti thatthere is virtually no asbes tos content remaining. Lining dusting or smoking during clutch or brake engage ment is basipafly canonized material from the binder, or nonasbestos: material 'from the fillers. In summary, there is no measurable amount of airborne asbestos' fiber;liberated to atmosphere during clutch or brake engagement, so there is no cause for concern that aChea1th hazard exists. JR.. W. Rosenow RWR/pl