Document a1mMaepNvv8DxwNQwjg2ep4VB

FILE NAME: Ford (FD) DATE: 1970 Nov 16 DOC#: FD106 DOCUMENT DESCRIPTION: Memo - Asbestos Emissions from Brake Lining Wear hVr^V :/ `- V a**''*', v j * 1 C \ t f K Intro Company ENGINEERING ANI) ' ' MANUFACTURING STAFF loverno er 1, 157^ To: Mr. H. L. Misch cc: Mr. D. A. Jensen Mr. B. H. Simpson 009682 Subject: Asbestos Snissions from Brake Lining Wear ' ' . . ' Studies of asbestos emissions from brake lining wear are being condi ctsd by . Dr. a. Gealer of the Scientific Research Staff. The brake lining wear test is conducted with a dynamometer stand which simulates stop-and-go ccnditions under variable load conditions. The ambient air is blown past the trake ' lining to simulate the actual driving condition and to cool the brake lining assembly. Brake lining wear materials are collected from this air stream with a membrane filter at a rate of about 1 CFK. A sampling duration of about ' . IvO hours i3 required go collect weighable amounts of the wear material. In his preliminary experiments, Dr. Gealer found about 12 asbestos iioers on . \ - a filter paper area of hO,000 square microns using the transmission microscopy , . technique. This corresponds to approximately 3 x 10" fibers per gram of wear / . : material collected. Although 3 x 10 fibers per gram appears to be' an enormous ^ number of fibers, when dispersed in the atmosphere, the concentration is extremely . low (see attachment A). V. ' - ' ; ' The present industrial hygiene standard, in the construction trade utilizing asbestos, is two fibers per cm3 at 8 hour exposure for 5 years. Tie calculations in attachment A show that the concentration of fibrous asbestos is cnly 0.65 fibers per cm3 if it is assumed that the total emission for one month is to bo spread over a given volume instantaneously. If wind velocity, fiheu size (larger fibers will settle out quickly), and the height of the inversion layers are considered, the actual concentration of fibrous asbestos is indeed believed to be very small. * Dr. Gealer is constructing an improved test stand which will bo usee to obtain more accurate information on asbes+es emissions. His test data will relate the humber of asbestos fibers emitted as a function'of weight lost by Drake lining wear. . `h . ' .: At the beginning of 1571' Professor Selikofi of the Mount Sinai.School, of Medicine, gave a seaLnar at Ford. Ha stated that asbestos emissions from auto.moDiles are very small when compared to those emitt-id by construction trades. I am attaching a-copy of a letter written by prcfe3sor Sslikoff for your information. In this PRODUCED BY FORD B000 C022 " rv ,r;; i . - . : ^ritr/S-rr: . '.J, 'IV _. -' - '- Mr. H. !.. Miser. November ':6, '>973 letter, he states that ". . while it is m y informed guess that brake linings contribute less than is coj monly assumed to. asbestos contamination of .the ambient air, 1 t:iink this should tx documented,. . . " Dr. Gealer intends to publish his fincings ' . 7. ;( Professor Selikoff is scheduled to visit Ford on November 23, 1970. A n y new inforna t:.on which may be d: 3cussed at this me e t i n g will be summarized for your informt: on. , . ' ; CONGCJRREJ BY: W. K. Brhob Autoiotiie ifci3sicms Office JSN/ij Atta :hme its ' * r* ; . 009683 PRODUCED BY FORD 8000 0023