Document v1OXkxMLyvZK9Q1jdrbBOQxrm

F eb ru ary 22, 1977 John Po Sehels, Chalrsan CTFA Task Fores on Hound Robin Testing of Consular Talcum Products Control Analytical XiSbcrmtorieis Johnson Johnson Research Center Seif Brunswick, 3J. 08910 Dear Jack: Enclosed are the results of my analysis of the samples (Set J) for the CTFA round robin analysis of consumer talc products for asbestifors asphibol minerals. As I mentioned to you over the phone February 3, 1977 # 2 was able to follow your method pretty closely. Dor instrument, * Phillips APD 3500, has a computer program for determining background and giving net counts during the steps scan. The principle used, however, is the Basse as the one in the CTF& method. Although we used the slits recoCTsended in the CTFA method, we find that a divergence slit of CL5 and a receiving slit of 0.3 seas give slightly greater sensitivity. lie did not foilcar the dispersion staining method for the optical micro scopy determination* Instead, we used a refractive index liquid between the RI of talc and that of aephiboles - The asphibolas were identified by the Beebe Hues' method and thGir oriehtation in polarized light. Arnold Shultxe, Divisicsi of Mlcr^iology, has evaluated and compared the dispersion staining and polarised light techniques. His comments are attached. If you have any questions please give me a call. cc: HJE HFF-440" . Jm HFF-441 ..HMD HFF-446 CHW HFF-446 . AES, .HFF-127 Sincerely yours, Clifton H. Wilson Division of Cosmetics Technology Bureau of Foods CHWrdce Approved: HMDaivs: 02 /2 2 /7 7 T nssmxzmrioe msEsnram m?zmzz n sm a is m t&lc bt x-sm BXFmS0M3zm md oraDCL mcso* (SST J) .. ;:..... # 10 ai 33 '44 x-msr D i^ m cn a i ' 4- in s o lit e f Ik w o lltft + T rte so lit* c m a i Miefoga? tre a o lit 4 tew al lt e 4* ^ slit Iv tO ; $$ * ^ 4''Trmsci : + tewptoyiut* u m oe z z n m n m oe ssestefcbm s a s s o ee m s s m s ih m e s r x s n a ra cto fcsa r kd a m oosgawr issar . io 21 SS.. 44 :m # vi-Wt m ;'T - t ' 'Zv;iS.... jH gr HOTg&efQgr ; - 4- te e sb lltiB 4*te S fe S teo o lit M oeoecoeir 4 Treaolitft + few oilit 4>ggesa&litft *4 4 *;: . :;*;:itttioyhglllt F ebruary 2S, 1577 Consents cci COT*. Hafeod J 4-1; A sb^ tifors* -fesshibola M istrals in C fessstic T alc, Part XI, A s^ stifo s^ Aeohibola M inerals by o p tic a l Kiosasaopy and D ispersion Draining (X&sosd X0-7-7&) D ispersion sta in in g - In tb s 1*605 liq u id tb s dLsyssrsicn colors saccfclcned in tba setbod w ill appear I f th e id n sr a l has a certa in refra ctiv e l a t e range/ bat otXser co lo rs or acne w in appear i f fe e range 1 d iffe rsa t* Tbe co lo rs sssy w r y even fo r differs*#: lo t s o f tb s s*a&- dossal aiaee a l l lo t s m y n o t hava the sarss r s fr a c tiw ind ices A ssineral lik e crocid olite w ill no dispersion c o lo rs in the 1.605 liquid,, because tbo liq u id ssad the ^ireesad hsv& no refractive* index in eoesssa fa r arr/ wss^alxsagtin In Kry cs^ rien o , s^yfoibolis fib e rs can b& d etected j e s t s s e a s ily by fe e ose o f p olarised lig h t (polarised in , analyser out) as by dispersion stedsdag, i f n o t sass^ w ily . Xf t a lc i s sarafeed-lii .4 liq u id w ife m ix&asz es&tal to car M dhsr than th e indesfc o f f& lc, and lct&zr than fe e low est ito&esc o f ss^M bole (fo r safaris l.S fO ). fib ers w ill stacd csst b rig h tly , e sp e c ia lly i f coo isocssss W7ma&> . ASS/dal: -Arnold E. Sg&uIs S&vista* o f Hi^tobiology l&gna^s o f Foods .w.v.v ::::::: v.v.t;: ::::::: .v.v.-.v ::::::: .*.V.V." Fahruaxy 2S, 137? CoB^ssfcs a C3S71 Hetsa J 4-1; A sb a stifo cs Jssbol M inarals in O s s tie T&Ie, Part XI; &sb&BtiiGOE3i Ass^iibol fu se r a is by Cptic&i Mtxscccrf m D ispersion S taiain g. (Xs&md I-1-7&) Dispoxsiess sta ia in g ~ In t& 3U6&5 ui^ ' th s 4L^?$r2im oe ls r s ssstloBed in tit asfebod w iU app&sr i -fes sta&ral bas a oe r ta in x efra ctiv e iadc rangs, bot ct$sr co lo rs or aras w i l l app*er i f range i s <Ufarst. To c s lc r s sy vary ever* br d if tosgsxt lofes o f the s*s& sns&l ais^ss a i l lo t s m y n o t hav th rase sfracfci^ indices* A finssssX lik s cm cidoX lte v i l i *s&* bo dispersion. eo lo rs in tse 1.685 licpaid, b^csisi# the JLl^dd egs tb s inssml rss^s no rofe feive indgse in eooa fo r any ^nvalcmgtiu In Et? essparienca, asfoiJhol lib e r s m n b dcted ftssfc a s o a sily by tba * o f p olarise^ li^ ife (pclartsad in , analyser eu t) ts by disparsleg sfceddisg, i f n ot sacra sN&Xy. Xf t a lc e sso^ ted i s .-* H ossi %dth an ii?c ogual to or M # than tbo h ieb o st isa5^ o f talc* & ta ssr &m :: fcho la a o st index of, JCgMbola (fo r assasp^ l,,S). f rs w ill srta e s t b rig b tly , tK p eia lly i f cos'iSoQasas .. V . ::::: :::::: :::::: / -:::: .v.v.v. -V.v.-.V AS/al Arnold E. Ssmis^ id visio o f H icnsbiology Asnasa o f fto s . -,v.v.v.;v .V.V.V.*/.; v.:;::;:: . r.v.v-v.v.-. /.V.'.V.V.V. ;::.v.v.v. `.*/.v.;:::: ...W .v.v.v.;;*.: *'..... *1vv/.::::::; .'.V.V.V.'.V. /..v.v.r.;: