Document mqEZpaEnbgXz9j3EKoK7OO7B0

TO: FROM: DATE: SUBJECT: COPIES: R. B. Norwood B. O. Stanley February 22, 1974 CTFA Sub-Committee; Talc Analysis Methodology J. K. Barr D. w. Holstein H. M. Stephenson G. A. Nells On February 19, 1974, the writer attended a meeting of the CTFA Talc Analysis Methodology Sub-Committee held at Johnson t Johnson's research center, New Brunswick, New Jersey. A list of the attendees appears in the attached minutes of the meeting. The object of this meeting was to objectively discuss all methods proposed to date for the analysis of asbestos and tremolite in talc and select the most promising ones for submission by the CTFA to the FDA. The minutes of this meeting are attached to this memo. Harold D.Stanley Group Leader - Research Testing HDS/jmb attachments '0017691 C IV^ CONFIDENTIAL 11713437 CONFIDENTIAL PFI KA 00000604 Minute of the & e t l n g of the .CTFA T u k force on ifethcdclogy for the Detection of Asbestos In Talc held at the Johnson and Johnson Research Center, Tuesday, February 19 197^. Present vere the following: Affiliation F. Robert Rolle, Task force Chalrean Johnson and Johnsen Rai Stanley ! William V. Risenberg John W. Stuart Walter Luckevica David H. Basier John P. Schals John K. facq C. J. Ftenaentier Xan M. fitevart Trygve Baak J. P. Sinko, Jr. D. Harri George Sandland Herb Conrad Pfiser pda/ep/ob/dm PDA Cesaetes Avon .Producta Johnson and Johnson ' Johnsen and Johnson Colgate-Palmolive Co. Cyprus Industrial Minerals Walter C. McCrone Associates Cyprus Industrial Minerals Colgate-Palsollva Co. Cyprus Minerals Corp. Bristol Myers Co. Johnson and Johnson OBJECTIVES Dr. Roll outlined the objectives of the task group to be: "development of methods f r the detection of fibrous aophibole and fibrous chrysotlla in cosmetic grade talc.i The methods must be applicable to finished products and oust meet the following criteria: a) must be specific for detection of asbestos in talc and It, or a folic* up method, must discriminate between fibrous and oon-flbroas farms of asbestos. b) m s t have definable detection limits. e) must be reproducible song different workers with different Instruments, d) must result in a pass or fail on a tale. Before proceeding to a detailed discussion of methods submitted by participants, details of talc inlu&lation studies were reported by Dr. Rolle. i i 0017692 CONFIDENTIAL PFI KA 00000605 11713438 CONFIDENTIAL PFI KA 00000606 PTHALATIgt STUDIES This work was done by Dr. F. D. Pooley In England to determine tbs mount cf talc a baby might breathe during powdcrlr^. The model system consisted of a dell which was sprinkled with talc to simulate powierin,;. The cu nt of airh'-rne talc was coloured using an M.B.S. personal air sor-pler which separates collected dust Into respirable and ncn-respirosle fractions. The point was node that 8 minutes of constant sprinkling were required to allow enough talc (aicrograa amounts) to he collected for coasirecont. Thesa data were then used to calculate the average number of talc particles a baby could be exposed to during a week. The calculation wna outlined in detail and the data were compared with presently accepted Industrial exposure limits for asbestos. It was concluded from these tests that even if tale were pure asbestos the levels cf exposure of a baby durin" ncrnal powder ing are far oelcv the accepted tolerance U n i t s . The results and details of tills experiment ore being prepared for submission to the FDA and C17A. a . Dgrm T icfl cr a m o t Considerable time was devoted te discussion of alternative definitions of a fiber other than the 3:1 axial ratio as specified in the Federal Register which is felt to bo unrealistic. It was decided, however, to stay with this definition because of a lack of medical evidence correlating geo metric factors with potential b e & l t . haxards. FARTCCUB 8ia Hal Stanley reported that particle size studies of various talc w p l f l submitted by participating CTTA members have been completed and that all are generally similar. These data will be submitted to the FDA to gether with the inhalation studies reported by J. and J. ANALYTICAL METHODS: Optical Microscopy: A promised method frem Johna-)tonvllle la under modification and was not submitted. Dispersion Staining - McCrcne Associates itlnciples of the dispersion staining method were presented by David Hamer. From his experience the method was reported to be suitable for tremolite down to levels of 0.1 percent but was not suitable for chrysotile. The principal reason is the size of chrysotile particles imich' ore generally below the limits of resolution cf the cethal. The m i n i m a dimensions of visible trernllte particles were estimated at 10 yn x 2 ys.. One experiment was cited where up to 7j chrysotile in a known spiked sarple was missed. It was pointed out that in finished product talcs other added ingredients might interfere with the method. A combination of color and gecoetric factors must ha considered when identifying a tremolite particle by this method. 0017693 11713439 CONFIDENTIAL PFI KA 00000608 - 3- X-ray Diffraction: X-ray diffraction procedures Ter trcmollte wers submitted by representatives fTra Pfizer, Johnson ar.d Johnson, and Cypras. Hal Stanley Indicated that Pfizer's technique far tremclite, hosed on step-scanning of the 110 reflection at 10.5C> tvo-theta, ha a a detection H a l t of 0.2%. Thera It general a^Tcenont that t..i detection U n i t can be reached by step-canning procedures, hut sore diso.~ecr.cnt as to the detection licit* achievable by normal scan.ninr. Since the 10.5b tvo-theta peak ia clmraeteristic of onphlboles and the cathod ia thus not specific for trcaolite, the question of bach-up methods was raised. Pfizer and Cyprus have used acid leaching followed by x-ray fluorescence for Ca as a bach-up for trcaolite. X-ray fluorescence is capable cf detecting to U n i t s of 0.1%. The possibility of interferences by Ca-ecntaining aubstancea, particularly in finished products, cust be considered. Dispersion stad nine ** alto an alternate provided size criteria are net. s {1* . Differential Thermal An*^yeia; * Differential thermal analysis as a method for terpentine cinerals in talc vas discussed by J. Sc'ielz of Johnson and Johnson. Tbiis netted was reported to detect 0.5 to 1.0% chrysotlle which exhiti'.3 two thernal events, an endothern at 650C and an exotherm at 830-8^0C. The netted is specific for nir.erals of the serpentine class. The method does not depend on morpholo/ry end in the case of positive responses cust be checked by microscopy. Valter Luckcvicz cf Avon confirmed J. & J. experience with DTA. Excellent agreement cn sarples exchanged between the tvo laboratories was reported. Base question as to the type of instrument used vas raised. Avon uses DuPont and J. and J. uses Stcne instrumentation. Hal Stanley of Pfizer reported no success using Eisner equipment. Trygve Saak of Cyprus indicated reservations wit- respect to reproducibility among different instruments and laboratories. X-Ray Fluorescence An x-ray fluorescence method capable of detecting 0.1% trenailte based on Ca analysis was reported by Cyprus. Acid leaching is used to remove acid soluble interfering Ca-containing minerals. The question of in terferences by Ca compounds, especially ia finished products, by flow 5 i agents or ether additives, was raised. Positive responses aust be followed up by another method such as S.E.M., dispersion staining or 6 TEH with SAED. X-ray flucreecer.ce is considered by Cyprus to be easier to *t quantify than X-ray diffraction. Atomic absorption can be used as an alternative for greater sensitivity. Electron HIcroccopy ~ The Pfizer method for chrysotlle in talc utilizing TEM and A M D we# presented in detail bv >5*. Stcr.lcy. Chrysotlle is estimated easily at 0.1% by weight, fiber counts f:r chrysotlle in unknown* are ccopaired with tavr.m nlxturca similarly prepared. Identification of fiber* as ebryaotile is mado by SAED. i | j j J J 0017694 CONFIDENTIAL PFI KA 00000609 11713440 CONFIDENTIAL PFI KA 00000610 Cyprus techniques are similar but include aluninun shadowing to get a better idea of particle c..apc and as an internal standard fer SAD. Levels cf chrysotilo are determined by count in comparison with standard. MeCrone methods vere discussed by Ian Stewart. They carry out diffraction studies at pctentials of 150-2CO kv. utilizing talc itself as internal standard. Quantitatic.i is based on area percent determinations versus standards. The procedure requires several hours to carry out. It was pointed out that at O.ll ciirysotilc the fibers are readily apparent in every exposure and can be readily estimated in a natter of. minutes. SAE2 is necessary to identify fibers as chrysotile. Materials with simi lar morphology thus are eliminated iron the count. MeCrone's method is sensitive to veil below the O.li level for chrysotile. The method la suitable in situations where a great number of different tale specimens are to .be studied. It was agreed that the Pfizer method would be used by the teak group since it is the most accurately specified. Sample size will be at tbt operator's discretion but must be consistent. Al uninun shadowing will be included. The test will be pass or fail at the 0.1% level. . Infrared Spectroscopy A n Infrared method, proposed by V. Luckewicz of Avon and baaed on aa absorption at 765 cn-1, specific for trenolite, was discussed. Chlorite is an interference and must be eliminated by beating. Although the M t h o d was deemed useful for qualitative indication of the presence of tremolite, It was felt that additional study of the quantitative aspects was needed before considering the procedure further. The following methods will be used in round-robla studies: 1) X-ray diffraction for amphibole; if positive, to be followed up by SEM or dispersion staining to see if it is fibrous. Two positives and talc fails. 2) Differential thermal analysis for serpentine; if positive, to be followed up by TEM to see if it is chrysotile. Two positives and talc fails. 3) Transmission electron microscopy for chrysotile utilizing a aplicad ssrple at the 0.l chrysotile level. If chrysotile is at the 0.l level or higher, talc fails. 1) X-ray fluorescence for calcium in amphibole; if positive, to be followed up by SEM or dispersion staining to see if it is fabrous. Two positives and talc fails. JF8:ag \ ( J P. 81mkot Jr. A 0017695