Document zzvw8ExeEXMRZEen2rdGgv0v7

f-4- SLIDE 6 This is a typical friction disc with its mating disc as is used in oilcooled, multiple disc brakes shown in the previous slide. Break Wear products: It is my understanding that the technical paper by Mr, Jeremiah Lynch of the U.S. Public Health Service on "Brake Lining Decomposition Products" has been entered into the record in earlier testimony before this Board at Granite City, Illinois. We have done similar, but less extensive work, on brake decomposition SLIDE 7 products. This slide shows scrapings from an unused brake as photographed with an electron microscope at high magnification. So you will have a better feel for this high magnification, the thickness of human hair at this same magnification would cover a screen twice as large as we have in this room. I have included a 5 micron scale on this and the three succeeding slides because Section 601 in the proposed Regulation states that "only fibers of 5 microns or greater in length...shall be counted" in the emissions from a factory into ambient air. We believe that if it is safe for a factory to emit fibers less than S microns in length, it should also be safe for a brake to emit fibers less than S microns in length into the ambient air. Additional research by qualified medical personnel may even show that asbestos fibers much larger than 5 microns are safe in the ambient air. Since these are fibers scraped from unused brake material, they are larger than S microns. CAT-1007390 015