Document Z88BOR1wjm3JJZgVYGELZ1jKV
EXHIBIT
WCD-381
REPORT OF CTFA.TALC SUBCOMMITTEE OH METHOD TO DETECT CHRYSOTILE AND
TREMOLITE IN TALC.
v
December 10, 1973
1 The Scientific Advisory Committee of the Cosmetic, Toiletry & Fragrance Association, 1625 Eye Street, N.W., Washington, D.C. 20006 at a meeting held on. September 2, 1973, designated that a subcommittee be set up to study the optical microscopic method proposed by the Food and Drug Administration. This method was published in the Federal Register of September 28, 1973. The present membership of the CTFA Talc-Subcommittee is- shown, on an-attached sheet. '
At the first meeting of the Subcommittee, it was agreed to submit
several samples of talc to members who volunteered to apply the FDA
proposed optical microscopic method. The following talc samples were
distributed without identification - except for randomly applied and
,non`-duplicated code numbers:
*
Italian Talc Montana Talc Montana Talc Vermont Talc
Alabama Talc
No. Carolina Talc
yr
'
Source I Source II
'.
In addition, a sample of Italian Talc spiked w/w with. 1% chrysotile and 0.15% tremolite was sent to each participant. The participants were aware that the sample was spiked, but did not know the percentage of spiking.
The attached table summarizes all reports submitted:
Final Report
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Sample
Spiked Italian. Montana- I Alabama Vermont No.Carolina Montana- n
No. of Fibers With R.I. Greater
Than 1590
No. of Fibers' With R.I. Less
Than 1574
Status With Regard to Proposed FDA Method
Mrs. Lucy McCroc|e, McCrone Associates for Chesebrough
320 120
0 0 0 0 0
16 0
0
0
0
o:
0
Passes Passes Passes Passes Passes Passes Passes
Mr. Harold Stanley of Pfizer
Italian Montana- I Montana- IT^.,. Alabama Vernon t No. Carolina Spiked
^ 100 -- 100 ^100 <---*100
Ipo /*u 100
<1000
>100 >100 >100 >100 >100 >100 >100
Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite Fails Chrysotile Passes tremolite
Mr. David Hamer of Johnson & Johnson
Italian
0
Montana- I
1
Montana- II
25
Alabama
0
Vermont
0`
No. Carolina
0
0 0 0 0 0 .0
Passes Passes Passes Passes Passes Passes
Spiked Italian
Dr. John A. Refiner (D. of Conn.) for Avon
632 , 220
12,930 1,114
Fails Chrysotile Passes Tremolite j.-i'ils Chrysotile -^'Passes Tremolite
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Sample ,
Ho. of Fibers
No, of Fibers
With R.I. Greater With R.I. Less
" Than 1590
. Than 1574
Status With Regard to Praposed FDA Method
Dr. John A. Refiner (II. of Conn.) for Avon Cont'd
Montana-I Montana-- L-L Alabama Vermont No. Carolina
0
` 13 25 41 14
5,844 9,281 15,125
165 11,852
Fails chrysotile .Passes tremolite Fails chrysotile Passes tremolite Fails chrysotile Passes tremolite Fails chrysotile Passes tremolite Fails chrysotilePasses.tremolite
Dr. Tryfigve Baak of United Sierra
Spiked Italian Montana;-! Montana-11 Alabama' Vermont No. Carolina
3,000 1,000
0 0 0 0 500
2,000 0 0 0 0 0
Fails Passes Passes Passes Passes Passes Passes
Richard E. Stevens of Ernest F. Fullam, Inc, for Whittaker C&it
Italian Montana-I Montana-H Alabama Vermont No. Carolina
8,250 18,000 29,250 21,825
3,225 20,850
1,350 450
5,200
6,075 675
6,000
Fails chrysotile & rremolite Fails chrysotile & tremolite Fails ,chrysotile & iremolite Fails chrysotile & tremolite Fails chrysotile & :remolite Fails chrysotile & -.remolite
Spiked sample was not run.
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Sample
No, of Fibers
No. of Fibers
With R.I. Greater -With R.I. Less
Than 1590
Than 1574 .
Status With Regard to. Pro posed FDA- Method
Mrs. Lucy McCrone of McCrone Associates for Kolmar
Italian MontanIa-I Montana-!!
Alabama Vermont
*No. Carolina
Spiked Sample
53
o 0 0 0 0 488
0 0.
0 0 0 0 16
Passes Passes Passes Passes Passes Passes Passes
.*Sample noted to contain some fiber bundles which are rolled up talc plus some non-fibrents tremollte
The following participants examined their samples but were unable Conscientiously to count particles with confidence, therefore, did not report numbers':
Miss Marie Jones for Dr. G. Cohen - Bristol-Myers Products Research Labs. Mr. Salvatore DiBianca - The Mennen Company Liberia Mutual Insurance Co., Research Center - for Kolmar Laboratories Mr. John Facq -- The Colgate Palmolive Company, Research Center
The table reveals strong inconsistency between results obtained by the different scientists applying the method to the same group of.coded talc samples. This inconsistency is the result of problems encountered In the methodology.
1. The alphi refractive index of talc - one of the two indices exhibite t by talc plates standing on edge - varies in value between L.539 and 1.5501. This in combination with item 2, below, miy easily result in the mis-classification of such plates a;! "fibrous, less than 1.574" and therefore chrysotile.
Dr, Refiner of the University of Connecticut, in his report to Avon, admitb that this factor is paramount - "counts for chrysotile are high since (talc) edges will often be mistaken for fibrous particles".
"2. The immersion method for the determination of-relative refractive Index becomes unreliable when applied to extremely small (ca. 1 jim)particles. This is due in part to the fact that particles around 1>*W in width approach the limit of resolution of the human eye when both size and contrast are considered, especially when applying the Becke line technique prescribed. This will
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2. cause eye.fatigu and resulting errors. Thus, a fine talc shard or plate on edge may b easily mistaken for an asbestos fiber. This applies to both' the chrysotile and amphibole
. portions'of the test.
3. It is quite likely that chlorite - a mineral of varied compo sition -commonly found in pharmaceutical grade talc - would be incorrectly Identified as tremolite. Refractive indices for 'chlorite vary in the range 1.57-1.662
The examination of a sample of .one milligram dispersed on a single microscope slide presents the investigator with a preparation which is too dense for a petrographic study.
The method is laborious and time consuming. Dr. Refiner
quotes an analysis time of about five hours per sampla and
at JOHNSON & JOHNSON the investigator (D. H. Hamer) estimated
at least two or three hours.
6. Dr. Walter G. McCrone in an earlier letter to the FDA suggested that there were relatively few scientists in the country who could use the method effectively. Scientists at Bristol-Myers, The Mennen Company,,Liberty Mutual and Colgate-Palmolive had great difficulty in following the method to conclusion.
7. The proposed FDA method implies that all fibrous particles in talc ffving optical properties similar to those of asbestos minerals are in fact asbestos. This is probably an unwarranted assumption.
REFERENCES :
1. Deer, W.A., Howie, R.A., and Zussman, J., Rock-Forming Minerals, Voi. 3, p. 121 (1962).
2. ibid, p. 131.
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We have concluded that the method published in the Federal Register does not provide a truly reliable means for the detection of asbestos in talc. It results in both false-positive and false-negative findings. It is also tedious and may consume as much as one half day per sample,
""The subcommittee urges that the Food and Drug Administration defer finalizing the proposed optical microscopic method and proceed into a Phase II program which would combine FDA and Industry in a strong effort to develop a truly reliable method for measuring chrysotile content in talc. We are confident that the detection and estimation of fibrous tremolite can also be done, if necessary, as a fringe benefit, at the same time.
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Wa estimate that a satisfactory method will take at least six months to a year to develop. We suggest a close liaison between. FDA and industry in this all-out effort with updating reviews to take place as frequently as necessary.
" Review of Alternate Methods
The CTFA Talc Subcommittee has reviewed several methods to detect chrysotile and tremolite in talc, including modifications of the optical microscopic method. These are listed with comments.'
1 Optical Microscopic Method - may be used, with some modification. ' Possibly better selection of R.I. liquids and reduction of sample size per slide.
2. X-ray Step Scanning - A good method for detecting tremolite if we could accept about 0.27, as the threshold of detection. It does not distinguish fibrous from nan-fibrous tremolite. The simultaneous detection of chlorite makes method impractical for chrysotile.
3. X-Ray Step Scanning + Optical Microscopy - Acceptable as in if2 above but the optical method continues to present the dilemma in reliable identification of chrysotile. However, this does not rule out a major revision of the optical method to do the chrysotile identification and counting.
,1
A . X-Ray Scanning - The problem of chlorite interference in the detection of chrysotile is present in all x-ray procedures thus far' available. It is reliable for the detection of 17. tremolite (both fibrous and non-fibrous).
5. Differential Thermal Analysis - This procedure is capable of detecting chrysotile at the 1% level, however, it will not detect tremolite.
6. Scanning Electr onMicroscopy - This procedure is not capable of identi fying asbestos. Even with energy dispersive analysis, completely satisfactory identification is not possible.
7. Transmission Electron Microscopy + Electron Diffraction - This appears to offer the best, most reliable method and is probably capable of detecting chrysotile and tremolite (fibrous), both at a level of 0.1%. It is estimated that an installation would cost about $130M +, and is obviously prohibitive for the small manufacturer who uses talc. The amount of talc sample examined by this procedure is miniscule.
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Summaty
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1 <iaa.Qj -s*-cs vnvifiv of the Optical
.The CTFA Talc'Subcommittee Was compl .r,,sotile and Fibrous Tremolite
Microscopic Method for
th^^Federal Register, vol. 38 {No. 188)(p- 27076,
in Talc, which appeared in the Fe"er ti^^ " f i n a l i z a t i o n of
Sptrtber.ZS, 1973). It " - r nV a a d Pl S o " ! ^ collaborative rff-ift
the proposed regulation on tf}lc.
f y method of estimating
L J e e / p p A 8 industry to resolve " 3 3 , ,,lth periodic liaison
ehrysotile and tremolite In talc,
force of industry experts
^ roi "
s^) V George`'fy. Sandland Chairman CTFA Talc Subcommittee
GWS;dd
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