Document da154axMkD734bon6kRxv1g45

w // To kM y \j ETHYL CORPORATION INTl-.R-OlTICh j. G. Burdick, M.D. Addiu.s-, Houston PliO.M W . E. Rinehart, Sc.D. Subject Asbestos Exposure Levels AnmtKs.s Date New Orleans October 23, 1969 On August 18, 1969, air samples were taken by Dr. J. Pierce relar tive to the use of asbestos-containing materials at the Houston plant. The samples were sent for evaluation to Mr. L. Schaefer, who is considered an expert in identification and counting of asbestos particles, at the Kettering Laboratories in Cincinnati. Sample sites, conditions and results were as follows Site and Condition No. of Asbestos Fibers (mppcf*) At breathing zone in carpenter shop during cutting of asbestos board with bench saw 0.3 At breathing zone in carpenter shop during cutting of asbestos board with band saw 0.2 At breathing zone during cutting of asbestos board at outside portable saw 0.1 *mppcf = million particles per cubic foot The value which is presently recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) as a Threshold Limit Value for asbestos is 2 mppcf. This assumes repeated 8 hour workdays under relatively constant exposure conditions. It is true that certain of the operations (power saws) produce a great deal of dust, which very well may exceed "nuisance" levels. The important thing, however, is that our sampling technique (which is more severe than the human respiratory system) did not reveal amounts of asbestos dust (fibers) at_ the breathing zone which we would consider hazardous under the operating conditions we sampled. Were these conditions to change substantially, the conclusions might be different. ETH 000005 Sheet #2 (continued) Memo to: J. G. Burdick, M.D. Re: Asbestos Exposure Levels October 23, 1969 Since excessive levels of asbestos during power saw operations were not found, I do not feel there is much likelihood of finding excessive levels in other locations (applying or removing insulation) and I do not feel at this time that further sampling is required. WER/af cc: Mr. M. C. Hudgins Mr. Wallace Armstrong W. E. Rinehart, Sc.D. Environmental Toxicologist ETH 000006