Document DdnGZD0wx2Mw7NLX2eDEMqwxa

r' C* 4/1/74 .Date COSV! BTiaty!;.'-'' :v4'-- r ;l y i'irra . ! A f \ 5 , v. - association im c. 1623 EYE STREET, N .W ., W A S H IN G TO N , D .C . 20506 PHONE (202) 593-2070 To The Talc Subcommittee From Norman F. Estrinl Ph.D. Please: Attend to Note and return I I Note and forward to L~` Files r n See (phone) me re '-- attached I Prepare reply for my -- signature I I Send me information 1-- 1 required to answer f i t For your information As per conversation . As requested I I For your comments '-- 1 and suggestions I I Does attached meet 1-- 1 vvitfi your approval? f I For signature, if you 1-- 1 approve 1 | Make----------------Photo Copies Other Remarks P LA IN T IFFS EXHIBIT WCD-397 Goodhue WCD 000193 A M E R I C A N CYANAM'ID COMPANY. C O N SU M ER P R O D U C TS DIVISION P. O , BOX 151, C L I F T O N , A R E A C O D E 2 Cr 1 NEW J E R S E Y 544- 7000 071S March S, 1974 Dr. Norman Estrin The Cosmetic, Toiletry and Fragrance Assoc., Inc. 1625 Eye Street, N.W. W a s h in g t o n , D.C. 20006 Dear Norman: I ashed our microscopist at the Stamford Research Laboratories to comment on the "Final Report of CTFA Talc Subcommittee" and sent a copy to Dr. J. Longfellow who requested that I provide you with as many copies as you deem useful. I, therefore, am enclosing eight (8) copies of the report. If more are needed, please let me hnow. F D B :dt F. D. Barbuscio Goodhue WCD 000194 I . t ' ,'-.f; r-': STAMFORD RESEARCH LABORATORIES RESEARCH SERVICE DEPARTMENT REPORT to M r, I r a n i : B a r b u n c io FRCM M icro sco p y material M e th o d : A s b e s t o s i n T a l c charge NO, 2096-35 ( 546- 7145) WORK REPORTED 9Y D . W. D a v i d e p t . C o n s u m e r P r o d u c t s ; f room no. ' DATE REPORTED 2- 25-74 i test M ic ro s c o p ic a l E x a m in a tio n DATE SUBMITTED 1- 11-74 i - NOTEBOOK REFERENCE S _ 1093l . P O . 110.111 : Introduction i- ' \ Our comments on the data you have submitted concexming the Dept; of Health, Education and Welfare's microscopical method 1 | for determining the amount of asbestos'in talc mayibest be divided into two parts; the test procedure itself and the Objections raised;by-the CTPA subcommittee after a round-robin trial. Test Procedure .i -1 1. Sampling, |, The method of campling should be specified. Micro- riffling would probably be universally acceptable for powders of allsizes and compositions; i !' 2, Size of Sample. : j The test specifies a weight of one mg.; depending on the .size-range of the talc product, this may be too much or too jii n t' i- . little ito be truly representative, '{ . ... i 3* Criteria for a Piber. .. . V .. ; Two of these criteria (li and iii) may become contra- dictor. These criteria stipulate that fibers must have a length o 5 micrometers or greater and a width of 5 micrometers or less. Thus, e| fiber 50 micrometers long and 8 micrometers wide (perfect ly possible) would be in conflict with itself! The aspect ratio and the'length suffice to define the fiber dimensions; 'width should not he specified. i i 4, Area to be Examined, i ;; i ! . t. ' /' '] Assuming that one mg, is representative,; the maximum area suggested for examination is 648 sq, nun. This seems unnsces- aarily -Large for routine microscopy, for it involves approximately 100 traverses of 50 fields each at 4001, or approximately 5000 fields,1 If the sample is well-dispersed, as specified, 10 equally-spaced traverses, involving about 500 fields, should be adequate. . > ESD=i ,r Goodhue WCD 000195 22096-35 General Comment . :J;_,-vv ,... . -'." j Our Microscopy Laboratory can perform.this test. However, we feel that the time required would probably be one tpctwo days per sample, if* the figures are to:be meaning ful. ' .' 1 t .. iObjections by the OHFA Subcommittee <. ' '' !/; ^ O b j e c t i o n iio. 1. 1 i `- . ; This objection seems invalid, since theitest re quires that, both indices of refraction exhibited by a fiber be below 1,574- if the fiber is identified as chrysotile.. . Also, ;lt seems unlibely that an experienced mineralogist would confuse fibrous talc,or edgewise, platy talc, with chrysotile, as other optical characteristics, i.ej, detailed morphology, interference color, change of relief on rotation, etc., would usually be distinctive, * /. . .- Objections Ho. 2, 3, A, 5, 6 and 7, ,j . " ' These all appear to be valid, General CommaTTh !' ] ; It is quite obvious, from the disparity Of results obtained in the round-robin trial, that the test, as presently designed, is not practical. Of the seven alternatives sug- gested, Ho, 1, (Modified Optical Method) still seems to offer the best chance of successful application by the industry. t i :. ,r .:f ""r- Goodhue WCD 000196