Document x11rKNQK2zkMgZ1xqo7YyORzm

FILE NAME: RT Vanderbilt (RTV) DATE: 1971 Sept 29 DOC#: RTV 160 DOCUMENT DESCRIPTION: Letter to Desert Minerals from Am. Conf. of Govt Ind. Hygienists RE Differentiation between Fibrous & Non-Asbestiform TALC !:-tV'M)**0-V*WCTM/f/** ..**a** AMERICAN CONFERENCE of GOVERNMENTAL INDUSTRIAL HYGIENISTS , v fc. J inV.,;" JV* <<*..*.. Sfi**- .WT>JM*pl - I t tu -WVW -* V**M*I September 29, 1971 H**rtr ' ` 11 b> t P * 1* p j P ; ) M/tr f f J 7 Mr. E* J. Ellsworth Desert Minerals, Inc. IO9I South Coast Highway Laguna. Beach, California 9265I Dear Mr,. Ellsworth; In answer to your letter of September 22 regarding a minralogie definition differentiating between fibrous and non-ashestiform TALC, I am pleased to quote from a very recent article that appeared in Science. September 17, 1971 "There is no firm minralogie definition of commercial talc and in most areas the mineral; talc, forms much less than half of commercial talc. The composition of commercial talc varies with the deposit. Vermont.mines produce a platy or granular ' v-W'-.f type of minaral relatively .free of asbestos minerals (1 ). New York and California talcs, contain more fibrous silicates, including anthophyllite and tromolite(2,5)." Reference l refers 'to Weiss and Boehner, Arch. Environ. Health lU, 3Oh (Ib/). Reference 2 refers to Wright, Talc and Soapstone, Calif. DLvrv. of Mines Pub., Bull. I76, San Francisco, I957. Reference 3 refers to Wells, Mineral Facts and Problems, U.S. Bu. of Mines, Washington, D.C., 1965. 4 Sincerely youre, Herbert E. Sfokinger, iff1.h....D. Chairman Threshold Limits Committee CRMC-HT-TALC-00010: