Document e79456RykN05bR0LNrdGM5XE9

Mr. Robert S Kogdelain, President Fag# 3 April 10, 1979 Remarks and Conclusionsl The teat# demonstrate that asbestos leyels are virtually eliminated by the use of a system employing brake encapsulation device connected to a REPA-filtered vacuum dust collector. Without the use of such equipment, flhar coaceatrationa during compressed air jet-blowing of brake drums ranged' from 6.6 to 29.8 fibars/mlllilitec, Howavor, when the Asbesto-Clene System was used, fiber concentration* on both the mechanic and dust collector exhaust were not detected, as verified by transmission electron microscopy. An Important exception to this is observed la lest #2, the sample taken on the operator. Prior to this test, this mechanic bad worked on brake jobs without using the Asbesto-Clene System and without changing his work clothes. This exposure had resulted Is contamination of his clothes, re flected In the high residual asbestos concentration of 59,000 nanograma/cubic meter and 0.3 fibers/milliliter. Is contrast, the operator in Test fl and Test M wore class coveralls. This points tsp the need to adhere to the 05HA regulations concerning special clothing, change roams, etc. to minimise contamination. The background asbestos measurements, of 400 sad 613 monograms/ cubic meter, are consistent with other background measurements taken during brake repair work. They are the result of residual coatani mation of the garage by asbestos. This study has been unique end fortunate In two respects; first because of che great interest and Importance of determining cbrysotlle asbestos levels In such circumstances. The data Indicate that the Asbesto-Clene System represents an outstanding advancement in Industrial hygiene procedures to control asbestos exposure. It has also bean a pleasure to work with you In preparing and conducting these tests. If there ore any questions regarding the results or conclusions la this report, please do not hesitate to contact me. AJOUjm Arthur K. kohl, Ph.D. Environments! Sciences Laboratory 007914 PRODUCED BY FORD