Document kmXYLJD7o0Z8M7L2QQQEM90jB

r INOUSTftlAl HVG2CNC A2A POLLUTION MORTON CORN. Pm. D.. B. Cm. E. consulting engineer 310 BOWER MILL BOAB PITTSBURGH PENNSYLVANIA 1322S March 25, 1970 rn ^ Pi/75 . * TELEPHONE 4IX - 1.4337 Mr. J. L. Hyde Pittsburgh Corning Corporation Research and Engineering Center 800 Presque Isle Drive Pittsburgh, Pennsylvania 15239 Dear John: KC" NC-i Re: Anticipated Lowering of Asbestos TLV and Tyler Plant Design I am writing to answer the question posed by Dr. Lee Grant (your letter, March 13, 1970) with regard to the anticipated lowering of the ACGIH TL\ for asbestos from 12 to 5 fibers/cm3, and the ability of the proposed TyleT ventilation system to meet this standard. As you know, we do not design ventilation systems to ensure a cer tain level of contaminant in.the environment; we design to remove it completely from the source. However, whenever men and house keeping practices are involved in the process, they introduce vari ables which design and fabrication procedures cannot take into account. The best ventihtion system can be fouled, up by poor house keeping practices or procedures by operators which do not utilize the available ventilation facilities. The Tyler ventilation system is the best one I can design for these process operations. The plant manager will have to be sure that the system is maintained to ensure proper hood face velocities and duct conveying velocities. If this is done, contamination will emanate mainly from scrap handling operations, which are poorly controlled at this plant and at the Port Allegany plant. There were many discussions of scrap handling practices at Port Allegany and my recommendation to discard the Butler Building was not ac cepted in the final analysis. The Tyler system design'is essentially the same as that used at Port Allegany, but it does not utilize the Butler Building, which is an improvement. In summary, the ventilation systems for Tyler and Port Allegany are excellent, with the exception of the scrap handling feature. If the 5 fibers/cc TLV is exceeded upon start-up, modification of the scrap handling procedures will be required. Sincerely yours, lHte document was not a record of PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. Morton Corn, Ph.D. Consultant 5313 4.