Document p2gjZarRoEV31n7q8pRMVOp37

FILE NAME Talc TALC DATE 1973 Feb 14 DOC TALC446 DOCUMENT DESCRIPTION Memo RE Talc Producers Association - Proposed Greenwood Plaza - 3 West February 14 1973 aa P. A. Martinson Ma 2. West ALC PRODUCER'S ASSOCIATION PROPOSED R. S. Lamar's letter of Januar3y1 1973 Dick Lamar's soundness of I would like letter suggested that I the letter before it is comment on the technical sent Before doing so to raise a question as to the desirability of sending such a letter ou after attending the recent meeting the Talc Producer's Association in New York City While the intent of the meeting was to promulgate a scries of definitions differentiating asbestos tremolite talc and commercial talc I believe I was instrumental in changing the end resulsto that only one definition is being proposed i.e. industrial talc While the exact wording may differ definition below the general gist very slightly from was as follows the Industrial talc from the mineral mineral talc and fibrous minerals is a product varying in mineral composition Sig020 tale . Mg6 other naturally ] OH to mixtures of associated fibrous and as defined by ASTM Designation D2946-71 While we should clear with the Vanderbilt people whether they intend to continue their previous plan to convince Government officials that tremolite is not an asbestos mineral my own impression from the meeting is that they are convinced of the futility of this approach The much more reasonable approach and one which has some slight possibility of bearing fruit is to concentrate on the definition of fiber The ASTM definition referred to above uses an aspect ratio of . 10 rather than the a ACGIH ratioof 1 R. T. Vanderbilt appears to be the spearhead for the whole effort to disassociate tremolite from the list of asbestos minerals If they are not going to push this approach then there is little need in my opinion for sending the letter to Talc Producers or to the Producer's Association So much for the political to the technical aspects of aspects the letter With reference I should like to make the following _ points some of which obviously will be minor 000058 : oo, e February 14 1973 Pago 2 A. Martinson - 2 West Iton 2. While tremolite does have a fibrous the particles can be fibrous or fibrous crystal habit In essence a of fiber is a particle with a defined minimum ratio length to width Unfortunately this aspect ratio D is not a definitely established limit As a matter of fact in theIn ASTM definitions there are two ratios given as minimum In the ASTM definition of asbestos mineralthse ratio is 10 in the Textile Fiber section the limit is given as 100 the However more important aspect ratio limit whether it has elt any more scientific significance or not is that promulgated SoS by the ACGIH namely an aspect ratio of 3. If the tremolite ' net particles have fibrous as far an aspect ratio greater than 1 they as OSHA is concerned If the ratio is are loss Rect than 1 the tremolite particle is a particle not a fiber ae Thus although tremolite is a fibrous mineral as stated in lee Item 2 the individual particles may be fibrous or may not be fibrous depending on their specific aspect ratios WER Starting with this distinction we go to Item 1 which says tremolito is clearly a member of the asbestos family of that minerals Again this is correct but since the asbestos are minerals fibrous by definition then we could conclude that those particles of tremolite whose aspect ratio is ex- tremely small are really not fibers and therefore they could be considered as not being asbestos What I am trying to point out is that whether tremolite iswhether to be classed as an asbestos minera is secondary to whether the particles are really fibrous or not insofar regulations are concerned and we should try to as the OSHA pin our argu- ments on the aspect ratio factor : . Item 3. ray diffraction methods make possible a positive differentiation between both minerals It will not definitely identify tremolite in a mixture containing small quantities of of tremolite in a large concentration talc Strongest identifying ray lines for tremblite are essentially the same as those for anthophyllite and several other amphibole minerals The statement that pure talc mineral is fairly common in nature is something that I must defer to R. Lamar's knowledge I had not anticipated that there were any large deposits of pure talc mineral without concomitant impurities albeit fibrous impurities such as carbonates oxides etc. 000059 Se SABSR REE STE S RUaoe TR ora * February 1973 Paye 3 P. A. Martinson= 2 West | Item 8 While I am sure that our Industrial Hygienists can supply information regarding correct procedures for dust control and other protective measures that may be required it will be a long time before sufficient medical or epidemio- - logical data are available on which to pass any recommendations other than to include tremouite as either an asbestos fiber in which case the fiber count limitations will be paramount or as a nuisance dust in which particle count would be para- mount Dick this tion Lamar is to be congratulated on preparing a summation ofinforma- type which brings together at one point pertinent informa- of a technical nature S. SPEIL SS CC i, W. L. VanDerbeek avy 2 West. J. M. Sharratt A 2 West . H. R. Keefe W. C. Streib R. P. Carter = ~ .2 West. - 3 West - 5 West R. S. Lamar - = 1 North - E. B. R. F. Smith Bassett ~ Long Beach Carson - Long Beach Carson eonps grepnaws pe merc . ie RMOENP 000060 cae ERY Ly