Document Xab4M0xQ4dRk9NpzY4XeXoxx

MEMORANDUM OF VISIT September 28, 1976 / // ff-yO BETWEEN: Ms. Rachel Scott, Correspondent The Washington Post and Heinz J. Eiermann, Director Division of Cosmetics Technology Ms. Scott inquired about any progress the FDA had made in regard to the "asbestos problem". She was doing a follow-up story and wanted to know whether the agency proposed?or is about to propose,regulations concerning asbestos as a contaminant of talc. I informed her that no regulatory action had been taken concerning asbestos in cosmetics. We were continuing our work on the development of instrumental methods for the determination of asbesti-form minerals and examined several samples of commercial cosmetic talc products. Once the methodologv has been w n r^^ o"t 'l~n our satisfaction wo may propose regulations on asbestos. Our investigations of talc products demonstrated that none of the talcs used in these products contained asbestos as a contaminant. She wanted to know whether their was still concern regarding the asbestos program. I answered her that since asbestos had been identified as a potential carcinogen, the agency would always be concerned about this matter and its potential health hazard. Heinz J. Eiermann /" 2 DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE PUBLIC HEALTH SERVICE DCST-77-1374 DCST-77-1375 DCST--77-1383 DCST-77-1384 DCST-77-1385 These samples consist of talc with known amounts of added chrysotile or tremolite. The talc used to prepare these samples is a commercial product which was analyzed by x-ray diffractometry -and differential thermal analysis. Tne analysis indicated the absence of tremolite, chrysotile and chlorite at the limit of detection. To make the samples as uniform in composition as possible, the talc and asbestiform mineral were mixed in a blender using alcohol as a mixing aid. The alcohol was then removed by evaporation and the sample remixed. George H. Boone 2 We -would appreciate receiving the results of your analyses when you have completed the examination of these samples. We would like to know the identity of the asbestos in each sample and, to the extent possible, the amount present. We would also appreciate receiving a copy of your methodology or a reference. Enclosed are some reprints of material dealing with the microscopic identification of amphibole and serpentine minerals. 'Thank you for your cooperation, assistance and interest. Ronald L. Yates TO: M em bers of the CTFA T ask F orce on Methodology for the Detection of Asbestos in Talc A t the S e p t e m b e r 11, 1974, m e e t i n g of th e C T F A T a s k F o r c e on methodology for the detection of asbestos in talc for cosm etic use, the results of our round robin analysis w ere discussed. The two ,fc o o k b o o k " p r o c e d u r e s fo r the d e te c tio n of c h r y s o t i l e and a s b e s t i form amphibole in cosm etic grade talc have now been modified as a result of this evaluation. The two methods would assu re that a talc is 99.0 to 99.5% free of asbestiform m inerals. A shortcoming of the round robin analysis for chrysotile in talc is that no one perform ed the n ecessary optical m icroscopy-dispersion staining back up method to the DTA procedure. This m ethod is of great im portance since the p rim ary method (DTA) is specific only to the serpentine class of m inerals; that is, antigotite, chrysotile, etc. which have different morphology's. E n c l o s e d you w ill find t h r e e c o d e d t a lc s a m p l e s p o s s -ib ly c o n ta in in g chrysotile. Would you please exam ine these sam ples strictly in a c c c r d u u ^ o with wux ^ r u p u s e u uoLicai r m o r o s c n n v - d i s p ^ r mn fo 'r ing test method, a copy of which is attached. I w ill co n tac t you by tele p h o n e o n 'o r a ro u n d O c to b e r 31, for your results and comments. Thank you, FRR/gm A tta.chment F. Robert Rolle, Ph.D. C hairm an, T ask Force on Methodology for the Detection of A sbestos in Talc 4- - Optical M icroscopy and Dispersion Staining "Having failed the DTA test for serpentine m inerals, the sample must next be tested by optical m icroscopy/dispersion staining or by tra n s mission-electron microscopy. The following optical method uses the Becke line procedure for deter mining relative refractive index. . 1. P r e p a r e a m i c r o s c o p e s l i d e by d i s p e r s i n g a p p r o x i m a t e l y 0 .3 m g . of talc in C a r g i l l e r e f r a c t i v e in d e x liquid 1. 550, u n d e r a 22 x 22 m m . cover glass. 2. On examination with the polarizing microscope any chrysotile fibers or fiber bundles in the prepared slide w ill exhibit: a. in the crossed polars mode, low order (first order, grey-white) retardation colors and straight extinction characteristics. ---------- fcu-----f ih ro n ^ -mo r p h o lo g y - in m o s t c a s e s a length: ^ r a t i o of several hundred on^, c . in the p l a n e - p o l a r i z e d lig h t m o d e a. r e f r a c t i v e in d e x m atch when the long direction of the fiber is parallel to the plane of polarization. In the plane perpendicular to this the fibers will exhibit a refiactive index less than that of the liquid. 3. Repeat 1 and 2 using C argille refractive Index liquid 1.544. Under these conditions for 2.c. (above) the refractive index m atch will occur when the short (diam eter) direction of the fiber is parallel to the plane of polarization. The other index ex hibited will be greater than that of the liquid. 4. U s in g the s lid e p r e p a r e d in 1, e x a m i n e the s a m p l e in the d i s p e r s i o n staining mode with central stop (dark-field). Any chrysotile fibers present will exhibit blue colors, distinctly separating them from the non-chrys otile particles. If this test is carried out with plane polarized light as the illum i nating source the color exhibited will vary with fiber orientation, so that as the stage is rotated the chrysotile fibers will change c o l o r ; blue --> b lu e - p u r p l e . 5. - - Again, for positive confirmation, both color and morphology (fibers, large l:d) c rite ria m u st be satisfied. If optical m icroscopy/dispersion staining gives negative results, chrysotile may be present with a diam eter too sm all to be detected by optical microscopy, thus, transm ission electron microscopy with SAED must be employed. Following is the transm ission m icroscope p rocedure. If chrysotile serpentine is detected at the sam e level found by DTA by either m icroscopical method, then the talc fails.