Document g2MZ0OR30X0LLEbok82JY9eZa

t Mr. J. A. Dierdorf General Supervisor Safety and Environmental Health Clairton Works Sutjaet: Analyses of Insulation Materials Ujuted Iniararganixation Corraspondanea Date August 27, 1981 Fnai: J. F. Quealy Senior Environmental Health Engineer As requested. Environmental Health has analyzed three bulk samples of insulation materials submitted by Jim Santory for determination of possible asbestos content. Two of the samples were Transite board from the Benzene Lab and Transite pipe from the Electric Shop. The third sample was identified as crucible tray insulation from the Benzene Lab. Transite is a trade name product of the Johns-Manville Corporation. It is a composite asbestos/cement material extensively used in rigid insulating board or pipe applications. Johns-Manville has informed us that it contains approximately 35% chrysotile asbestos, by weight. We confirmed the presence of chrysotile under polarizing light microscopy, using the dispersion staining technique. Microscopic examination of the crucible tray insulation showed it to be composed exclusively of homogeneous fibrous material. These were long, singular fibers, unlike the fibrous bundles generally found in asbestos. In addition, the uniform fiber diameter of approximately three microns was somewhat larger than those usually observed in asbestos. Under polarized light, these fibers were found to be an isotropic substance, i.e., having only one index of refraction such as fiberglas or mineral wool. This test eliminates any possibility of the material being asbestos. JFQ/jmr USEI000105