Document 4a8wxnV7Q2NjXZZEakXJ6NxQp

-V '' .VlkA-A 6.-- A.-'~. J f; Hr. J. F. Ballew, Jr. Building 70-108A INSTITUTE PI-A2ST Ms. B, J. Mitchell Mr. J. G. Perkins Mr. F, Williams ! IU p /r? if ' PLAINTIFF'S EXHIBIT April 6, 1976 E.R, - Industrial Hygiene You have asked that measurements be made of personnel exposure to airborne asbestos fibers while weighing dishes are being prepared for resi due analyses. Our records show that a similar measurement was made in Specifications Laboratory Room 205, March 10, 1975, and was reported to be slightly above threshold limit value (II:v'). Three determinations have recently been made by fiber count on filter samplers worn by employees while preparing sample dishes in the Analytical Laboratory Room 108. The results of these samplings are as follows: Date Employee Fiber Count/ml Air 12/22/75 1/12/76 3/1/76 C. W. Levers D. DeLoca J. 0.. Good 4.9 47.6 7.7 We observed each of these, samplings to be similar in technique and airborne dust was not visible in either instance. The TLV for asbes tos dust exposure is currently 5 fibers greater than 5 micrometers in length per cc of air as a time weighted average (TWA) and a oeiling value not to exceed 10 fibers greater than 5 micrometers in length. As of July 15 1376, the TLV will be reduced to 2 fibers as an OSHA. allowable limit. This job task is only infrequently performed and it is unlikely that the TLV as TWA would ever be exceeded. Our measurements-, however, shew that the ceiling level can. be excessive. We, therefore, recommend that work involving preparation of sample dishes with asbestos fibers be performed, within an exhaust ventilated hood, c*c-0 H. H. Frazier" AOi'O / .J UCC 008858 iiiiiMiirawiiroiirnnii^^