Document DM0aB6x0qYLGZ4wXxzgvxykGO

1.4 Reliability of the membrane filter method and Its use for enforcement While it may be that the proposed 0.5 fiber/cc limit is essentially a "no detectlble asbestos" limit, the facts are that during industry's endeavors to comply with the existing limit, and the July 1, 1976 limit, asbestos counts in the 2-10 fiber/cc range have been most difficult to reproduce. While skilled counters may have readings varying by 0.5 fiber/cc on the same sample, tests made at the same work station under Seemingly identical conditions will vary up to 2 fiber/cc. A standard is being proposed (0.5 fibers/cc) that is less than the variations encountered in the relatively clean areas of 1975. Industry appreciated that the membrane filter method is the only tool available for fiber counts, and realises it must be used to clean up the work area. However, the use of this membrane filter method for enforcement of the 0.5 fiber/cc limit is of serious concern. Users acknowledge that the membrane filter method is not an accurate reproducible means of quantifying asbestos concentrations. The friction materials industry expresses their objection to the use of a tool--with questionable reliability--as a means of enforcement of a very tight numerical standard. 1.5 The proposed exposure levels will expand applicability of the standard to brake lining shops, car dealers, etc. The proposed expbsure limits, and the proposed ceiling concentrations in particular, would bring.'.most-garages with brake lining work, as well as their suppliers (re-builders, job shops, and the/like) under requirements of this standard. Equal enforcement would mean that the regulated area, monitoring, ventilation, record-keeping and other requirements Intended for manufacturers would now be required by these small businessmen. FMSI03254 T