Document p2QGDpB9R138Dkga4nLnOrn8D

m Johns-ManvOI* Internal Correspondence k R. D. UekMiM'IS One Kerch 7, 1975 n* R. 1. rrlckhi-ss cni o. j. RlMO*erSR, <1. UMdi>JR W. 1. Rsit:-4V, 0. L RMUee-tf, File. Chrono * *** ASBESTOS SUILT-0W BOOFrFi A*ID HEALTH TOOK BOTE OS ftABCB 20. 1975 Sine* 1972. Johns-Vanvilie has ran auite i few tests on roofino dobs, both new roo'ine as well as tear-off. to detomino if asbestos fibers are released to the air. The fiber counts are ouite low. The esreoent TLV for asbestos fibers is 5.0 fibers/ec and. 1b July of 197S, the TLV is scheduled to drop to 2.0. Zn lookino at all the data attached. I find no fiber level as hieh as 2.0 fibers, and with the execution of an earlv tear-off (St. Hocis suer), none of the lobs even reach 1.0 fibers. It would aeoear as thooqh new roo'ino. where the fibers are clearlv bound bv saturant. have levels that are barel*' de tectable. Tear-of's, which will be very variable in con dition. swthodolocry. etc.. can have flicker levels but still apparently within the 197f orooosed standard of 2.0 'ikers. The total dust eaneratad tmalnlv ron roo* Insulation) can be considerable and this would contain oerlite. class fibers, etc. Zt would aoooer that (ss in anv demolition) oood vorpractice would require resuiretors and eye nroteetior. 'or yoneral protection. The aabaatos levels, however, would be Zf there is any question that renaina unanswered, it would be whether the 2.0 'ibers is trulv a valid TLV. Bv definition, no harard should oxist as lone ss lovels ara below the tlv. This TLV la at least beinq queationed by Dr. Selikoff. The British Occupational Fyniene Soeiotv is reevsluatina date on Turner Brothers Asbestos Ltd. to sse if the 2.0 TLV la reasonable. If it is, asbestos BUB looks very safe. K. L. Frieklae