Document g8KBeqQ3130oRkeZXGNbjnOV

FILE NAME: RT Vanderbilt (RTV) DATE: 1974 Oct 9 DOC#: RTV015 DOCUMENT DESCRIPTION: J-M Memo RE FDA Optical Methods for Counts of Asbestos Minerals Meeting OSHA Definition in 4 Talc Samples Produced by RTV dohns-Manvilie mesp?:^. R. S. Lamar - R&D Data: October 9, 1974 V. E. Wolkodoff - R&D Distribution at End of Memo FDA OPTICAL METHODS FOR COUNTS OF ASBESTOS:MINERALS MEETING OSHA DEFINITION;IN FOUR TALC SAMPLES PRODUCED--BY R. T. VANDERBILT COMPANY 1. Through J. P. Leineweber ^Rr~7E7 ~~atter has requested that this memorandum listing asbestosfixB^rScounts on four samples of talc from R. Tv-Vanderbilt^j^mpanyr(submitted by Charles Wagner Company ji?e-irdxxsdesk on Friday, , October 11,1974. 2. The R. T. Vanderbilt Company talc samples are identified as follows: . 1. Lab. No. RC-74255-1 2. Lab. N o . RC-74255-2 3. Lab. N o . RC-74255-3 4. Lab. No. RC-74255-4 . Nytal 200 Nytal 400 Asbestine 3X Asbestine 325 samples are extremely complex due to types of asbestos^eing present, the J-M modified optical method 'Could H5t be|used`:'for each,determihationgbutyrather we had to use the.FDA MicfoscopicaT:;?DefebfibnffOf^Asbestos in,Talc by Arnold E. Schulze 'and-Wil^ian^V.yEisenberg issued on Augrust -20, 1973. The" ;JfMfjm^i%'a;e'd<bptical technique, however, was used o n eachl'-SaM^lesV,(clarified Mi 11ipore membrane) in conjunction with-Zernecke phase contrast microscopy as a check on the total number of fibers in each sample. In all testsionly fibers meeting OSHA definition were counted; that is, at least a 3:1 aspect ratio;and fiber lengths have to be at least 5 microns or longer., 4. Total number of (asbestos fibers)per mg in each sample: a. Nytal 200 b. Nvtal 400 c. Asbestine 3X d. Asbestine 325 1, 055,000-fibers/mg 2.146.000 fibers/mg 1.460.000 fibers/mg 1.526.000 fibers/mg 5- Fibers per mg of each /Asbestos component for the four CRMC-ELS R. S. Lamar (2) October 9, 1974 samples studied are as follows: SAMPLES TREMOLITE CHRYSOTILE ANTHGPHYLLIT iytal 200 Nytal 400 Asbestine 3X Asbestine 325 604/000/mg 1,931,000/mg 876,000/mg 992,000/mg 300,000/rag 86,000/mg 561,000/mg 503,000/mg 151,000/mg, 129,000/mg . 23,000/mg 31,000/mg The predominant.fiber.in each sample is Tremolite which can be somewhat biocky,.with clipped ends/ is;-very ;harsh, but most are:'narrowi:andfrigid;Afibers. ^TheiGhr^so.tidie' ranges from siflky (very small percentage)-, bundles of few fibrils, and bundles'containing numerouis`fibrils. In general, the Chr-ysotile is considered medium-harsh, to harsh. The AutKopKiliite is characterized by having very narrow diameters, being extremely rigid, being almost spear-like since individual fibers can show,one end as acicular (needle-like) and others show a double termination of acicularity. 6. By transmission electron microscopy (TEM), six plates were taken of each sample. One print of each sample to show at least !a few Ghrjfsotile.fibers:are attached: and the magnification is 11.0Q0X. At this magnification 1.1 cm equals one micron. The TEM plates on file are as follows: a. Nytal 200 b . Nytal 400 c . Asbestine 3X d. Asbestine 325 TEM Plate Nos . 2301-A-F TEM Plate Nos. 2302 A-F TEM Plate Nos. 2303 A-F TEM Plate Nos. 2304 A-F All plates were taken at 4400X, and after enlargement for prints, the magnification would be 11,000X. All TEM plates were taken on our RCA EMU-3B electron microscope. We had planned to use a better model, Philips 200, at The Denver Research Institute for greater CRiviC-ELS-005165 R. S. Lamar October 9, 1974 clarity, better resolution, obtain plates at higher, magni-. -a fication and do selected area electron diffraction to prove the identity, of the asbestos, minerals; (which cannot be done on our RCA model), but the instrument at DRI was , not available for our use at the time; and in all probability^ even if available, the work could not have been finished by October111, 1974, since the optical work took a great deal of time. 7. If better TEM micrographs are needed with selected area electron diffraction.patterns for your PDA presentation, and if you. somehow can get additional time before the presentation, I will make arrangements for our use of the Philips 200 electron microscope at DRI. l/. Z tiukrfj V. E. Wolkodoff Applied Research Section jc Distribution: R. P. Carter E. M. Fenner Paul Kotin, M.D. W. B. Reitze F. J. Solon, Jr. G. L. Swallow A. C. F. Pinkbiner, J. A. McKinney H. R. Keefe P. A. Martinson C. J. Sulewski W. L. VanDerbeek R. G. Riede - 4N - 4N - 4N - 4N - 4N - 4N III - 5W - 5W - 2W - 2W - 2W - 2S - 2S F. L. Pundsack J. P. Leineweber W. C. Stt'eib A. J. McArthur S. Speil NOTEBOOK 4454 pp. 70-77 CRMC-ELS-005166 CRMC-ELS-005167 CRMC-ELS-005168 1;1 ' TEH Asbestine ?X, RC 7425'.>--> EM-2303H LI,00OX CRMC-ELS-005169 CRMC-ELS-005170