Document zomLLoELb7ja3aZ29XwBmJvxg

United States Department of the Intenor BUREAU OF MINES 0 0 LA SA LLE. ROAD AVONDALE. MARYLAND 0 7 8 i i<;*' April 26, 1984 Mr, George J. Dippcld, Vice President Whittaker, Clark & Daniels, Inc. 1000 Coolidge Street South Plainfield, Dev Jersey 07060-1000 * Hm y >' - , i * " n*,V.' - % Ft 4 ',/ - y..& ST `.!,.* Dear Mr. Dippold; *>* & -I S i The IB talc samples received in March 1964 have been examined using polarized light microscopy fPLM), F-ray diffraction (XRD), and transmission electron ' microscopy (TEH). The samples were examined for the presence of asbestifor* mineral particulates. The mineral serpentine is present in minor amounts in samples 72 OTGRRx, 720TGRPd, 720TTPRX, 720TTPPd, 720TTERx, and 720TTEPd. Only the platy variety serpentine was observed; no chrysotile, the asbestos variety of serpent i:?, was observed by PLK or TEM* ri/r i Approximately 1/2 to 1 weight percent treaolite is present in samples 720TTPPd, 720TTPRx, and 720 TTEPd. Trace amounts (<l/2 weight percent) wereobserved in samples 7Z0TGRJfc, 720T02Pd, 720TDMPd, 720T13Pd, and 720TDMR*. A l l tremolite particles observed using PLM were blocky with maximum aspect ratios of approximately 8 to I. Some abort, thin tremolite particles with widths below the resolution of the light microscope, were observed using TEM. The msximisr aspect ratio observed by TEM was 20 to 1 with most of "the elongated tremolite particles being 10 to 1 or less in aspect ratio. Some of the tremolite observed in these samples would meet the current regulatory dimensional definition of asbestos (>5 ue in length and >3 to 1 aspect ratio), Vsi Fourteen of the eighteen samples contained fibrous talc in trace to minor amounts. Aspect ratios of the fibrous tal; particles were generally leas than JC to J with a few particles- approaching an aspect ratio of 20:1. Many of these particles exceed 5 utr. in length and meet the morphological criteria of a regulatory fiber, however, they would not be classified as asbestos. f* " r. m ' m* * HT- 0 f d o t n - V. ' ClASi. i ^ u n t f ^ EXHIBIT .V$J? These analyse* represent only the *amples submitted for examination. If yo?i hive eny questions concerning the analyses, please contact Robert Virta at (301)436-754], or call me at (301)436-7501.. `" Sincerely, , /1 i- i Enclosures: Figures 1 and 2 cc: Robert A. Clifton, Jr. V i l l i J. Campbell Research Director sv A *v, u -V,- '% -v-' 'Vi? WCD000929 / r.:~ 'V / FIGURE 1. - Electron micrograph shoving platy talc particle* observed in sample 720TEEPd e p**> f i.* Mr r- & C t f w jir: t." ci I..- B.> FIGURE 2 , - Honrepresentetive field of view of sample 72QTGRRX shoving talc ranging from platy to fibrous in morphology i i i I WCD000930 United States Department of the Interior BUREAU OF MINES 4900 LASALLE ROAD AVONDALE, MARYLAND I0B 2 April 26, 1984 pK .y T.^V^ Mr, George J. Dippold, Vice President Whittaker, Clark A Daniels, Inc. 000 Coolidge Street Sooth Plainfield, New Jersey 07080 1000 : Dear Mr. Dippold The '18 talc staples received in March 198A have been examined using poi ri reef light microscopy (PLM), X-ray diffraction (XRD), and transmission electron microscopy (TEH), The samples vere examined for the presence of ashestifer; mineral particulates. .ft -li ' j i* The mineral serpentine is present in minor amounts in samples 720TGRRx, . 720TGRFd, 720TTPRX, 720TTPPd,_ 720TTKx, and 720TTFd. Only the platy variety , of serpentine was observed; no chrysotile, the asbestos variety of serpentine, vas observed by PLM or THiv . Approxi.mately 1/2 to 1 weight percent trecclx.te is present in samples 31 720T!PPd, 720TTPRx, and 720 TTEPd. Trace amounts C O / 2 weight percent) were observed in samples 7201011*1, 720TO2Pd, 720TDMPd, 720T13Pd, and 720TDMRX. K x l trenolite particles observed using PLM were bloeky with maximum aspect ratita of approximately 8 to 1. Some short, thin trenolite particles with widths ` below the resolution of the light microscope, were observed using TEH, The maximum aspect ratio observed by TEK was 20 to 1 with most of'the elongated tremclite particles being 10 to 1 or less in aspect ratio. Some of the ; tremolice observed in these samples would meet the current regulatory dimensional definition of asbestos t> 5 urn in length and >3 to T aspect ratio),. Sir '.fif i 'x Fourteen of the eighteen samples contained fibrous talc in trace to minor amounts. Aspect ratios of the fibrous talc particles were generally less than 10 to 1 with e feu particles- approaching an aspect ratio of 20:1. Many of these particles exceed 5 pir. in length and meet the morphological criteria of a regulatory fiber, however, they would not be classified as asbestos. 0 ijct tlAiU * it* WCD000928 These analyses represent only the samples submitted for examination. If yo-^:. have any questions concerning the analyses, please contact Robert Virta at ' (303)436-7541, or call me at (301)436-7501.. ', Sincerely, & .| Enclosures: Figures 1 and 2 cc: Robert A. Clifton, Jr. William J. Campbell Research Director ;" i.-lt'T *v. i* WCD000929 FIGURE 1. - Electron micrograph bowing platy talc particles observed in sample 720TEEM Vy1 ^^ "4 FIGURE 2 , - Honrepresentative field of view of sample 720TGRRx showing talc ranging from platy to fibrous in morphology WGD000930