Document Zn6nKv8kVqM14bom5mJYx02Xp

UniimJ States Steel Corporation \0\ Mr. D. G. Wilson General Superintendent Homestead Works Interoroanlzition Carrdspondenet 0*U: From: August 17, 1976 W. c. Janes, Manager Environmental Health Subject: Asbestos Content of Vermiculite Environmental Health has received two samples of vermiculite used at Homestead for analysis of possible asbestos content. These samples were purchased front Insolite Refractories Company under the trade name-.--HZonolite* and from J. p. Austin As.s.o.C:ia.te.s Inc. under the name, "A-Tops." Vermiculite is a hvdrated which expands to approx imate Iy t to 25 ties"i-s when heated to 2000F. Its principal use is as an insulating material. It is found chiefly in Montana but also in North Carolina, South Carolina, Wyoming, Colorado and South Africa. W. R. Grace & Co., a major miner, processor and supplier of vermiculite, has informed us that vermiculite ore deposits contain a "tramp* material which they have identified as tr.emolite, defined by OSHA as one of the asbestos family. Grace has found tremolite in the ore from both of its deposits, in Montana and South Carolina. Grace distributes its vermiculite under the trade name Zonolite. All suppliers selling vermiculite under this name purchase the product from Grace & Co. Examination of both Homestead vermiculite samples by optical microscopy using phase contrast illumination indicated a small amount of asbestos in each sample. Environmental Health recently conducted identical examinations on samples submitted by all U.S. Steel plants using vermiculite. Thpg** analyses sr>rVi a considerable number of asbestos fibers in the unexpended vermiculite oreT rt~~S>6e'ars that most of thr aTfrr*-<*-/vv during the ore expansion process. However, even with the expande "vermiculite, asbestos fibers were observed in virtually every sample. A. S. Patterson, Supervisor of Safety, was notified of these findings in a letter dated August 10, 1976. JFQ/mdd I IP1 W. C. fijmes ASB 0028626 I