Document Ev4ebDMw0eGGvOJZnGbM3JBxg

ETHYL CORPORATION INTER-OFFICE MAR 1 9 19791 To D. G. Goates Address Houston Plant From P. J. Sanders Subject Insulation Removal - Na Building Address Houston Plant Date March 13, 1979 The following is intended as a supplement to my letter to you dated January 29, 1979. The insulating material removed from the line used to transfer sodium from the #1 filter to the weigh tank con tained 2% asbestos. The samples collected to represent the exposure of the two carpenters who used saws to cut away segments of the insulation showed concentrations of 1.7 and 3.2 asbestos fibers >5 microns in length per cubic-centimeter of air. These peak concentrations occurred during 25 and 19 minute periods, and therefore, should be considered in relation to the OSHA ceiling limit of 10 fibers/cc. Eight hour time weighted average exposures, assuming no other occupational exposure to asbestos, were calculated to be ~Q.l fibers/cc. The current OSHA standard is 2 fibers/cc as an eight hour TWA. The samples collected on 1/17 to represent the exposure of the carpenters during the stripping of the insulation and clean-up of the work area were 0.4 and 0.3 fibers/cc averaged over the 115 minutes they worked with this material. Cal culated eight hour TWA's were less than 0.1 fibers/cc, assum ing no other exposure to asbestos. Bulk samples obtained from the insulating material of lines from the #2 and #3 filters to the weigh tank are composed of 4% amosite asbestos. Proper precautions should be taken if it becomes necessary to remove these lines. PJSrbto cc: W. F. Armstrong/A. 0. Wikman J. G. Burdick/G. B. Meyers C. B. Hunt C. J. Lowe R. L. Mack J. D. Roper J. T. Rucker G. L. Ter Ilaar File: Operations - Houston ETH 002372