Document k67GzVR6KpOOj8NdBKvpYD9Dq

DIVISION and LOCATION Mr. H. T. Dickinson date: October 27, 1-976 subject.- General Electric Company Salem,.Virginia Data on brake lining decomposition products is quite sparse and that which does exist,, relates only to asbestos emissions from vehicle .operations or brake. dynamometer tests ' Enclosed are copies of a.pamphlet produced by the Asbestos ` . Information Association of North America "Asbestos and Brake Linings'* and two scientific papers referenced in the: . * pamphlet - "Brake Lining Decomposition Products" by Lynch and' "Brake and Clutch Emissions Generated During Vehicle Operation" by Jacko et al. hVls.M ^ v4V-**>>*>^i- V'1* Laau> . ** ju 4 friction materials will vary according to the temperature created during the braking operation. Note the following statement in the preface to the Jacko paper- "friction material emissions are generated by . wear j- Abrasive and adhesive wear are considered to be the most important 'mechanisms below approximately 450oP; thermal wear predominates above 450 F. The organic constituents pyrolyze or oxidize -^r-. n-rrtp>nar>r>r>ivg:-.- / solid particles or gaseous reaction products. The asbestos fibers are pulverized into small particles Which are either trapped in the brake (or clutch) housing,, fall to the road, or are emitted to the atmosphere. Host of the asbestos is heated td temperatures high enough to cause chemical conversion and ' * is therefore trapped or emitted as olivine or forsterite particles. --- According to the jacko study only ,3% of the dust created by automotive braking survived as asbestos. The remainder was converted to an inert substance known as forsterite. > PLAINTIFF'S EXHIBIT urf'O'LlSV PLAINTIFF'S EXHIBIT GEWVOCT04-011479 WV-21591 Mr# H, T. Dickinson 2 October 27, 1976 The conditions observed' in the Jacko study may. not be duplicated in the operation of the G,,E, brake assembly if the operating temperatures are different. However, it makes little difference so far as OSHA is concerned because the only thing that counts is the level of airborne concentration in the ' I&reathinq zone of workers. The only way this can be determined is bv monitoring the work place where the brake assembly is- used. G.E. has an industrial hygiene- department, with headquarters in Bridgeport, and I am sure they are quite ' capable of. ..making this determination. Please let me know if you need any further information, : /as Enclosure cc: fir. Ek McBrearity - Atlanta GsBorne " ~ GEVWOCT04-011480