Document 2JGekGEX7rXKD2oL041DX4e8R

February 22, 1^77 John P. Schell Chairman CSPA Task Fere on Scmad Sabin Testing of Consumer Talcum Products Control analytical laboratories Johnson t Johnson Beseaxch Center Set? Brunswig, H.J. 0SS10 Dear Jack: Enclosed are the results of wy analysis of the sab l e s (fist J) for the CTFA round robin analysis of consumer tale products for asbestifors .asphitoole minerals. As I weatioced to you ovr the phone February 3, 1977# .1 was able to follow yossr sotted pretty closely. Our instrument, 'Phillips APB . 3500, has a couputer program for determining Istekground and giving net counts during the step can. The principle used, however, is the caste as the one in the CTFA siathod. .J a t h o s ^ we used the slit reccraaended in the CTFA etbod, we find that a divergence slit of 0.5 and a receiving slit of 0*3 sas give slightly greater sensitivity. lie did not follow the dispersion staining asethod for the optical micro scopy defeeraiaatitm. Instead, we used a refractive inda* liquid between the EX of tale and that, of :sphii>ales. The ampkiixjles were identified fay the .Baste lines' method andtheirteitetefcic* in polarized light. Arnold Shaltre, Division of Microbiology, has evaluated ted co*Bpar*d / the dispersi^ stainiBg and^polaxised, llghttechnlqus:. His cosmsent ; are ttaohed.'-'f;-^: ' .- . .-- - Xf ycu teve any questions pleas give ae a 1 1 . (b) (5) Clifton H. Wilson Division of Cosreetlcs Technology Bureau of Foods (b) (5) T nssmxzmrioe m sEsnram m ?zm zz nsmais m t&lc bt x-sm BXFmS0M3zm m d oraDCL mcso* (SST J) .. ;:... # 10 ai 33 '44 x-msr D i ^ m c n a i ' 4- i n s o l i t e f Ikw olltft + T rte s o lit* c m a i Miefoga? treaolit 4 tew al lte 4*^ s lit Iv tO ; $$ * ^ 4''Trmsci : + tewptoyiut* um oe zz n m n m oe ssestefcbm sa sso ee m ssm s ih m e sr x s naractofcsar k d a moosgawr issar . # io 21 SS.. 44 :m mv i - W t ;'T - t ' 'Zv;iS.... j H g r HOTg&efQgr ; - 4- teesblltiB 4* t e S f e S teoolit Moeoecoeir 4Treaolitft + fewoilit 4> ggesa&litft *4 4 *;: . :;*;:itttioyhglllt (s) (q) USI rsz Staad at- fcrLhtly, aapeeially ac 'ss Scfcala