Document kmdJ5NoGJq02rvw0G67VkVxBV
* ; y A S T A M X JL >
AMERICAN
CYANAMID
COMPANY
P . O.
CONSUMER PRODUCTS DIVISION
BOX 1S1, CLIP TON, NEW JER SEY
A R E A C O D E J o t J * S - 70og
0Y01S
Marchi., 1974
Dr. Norman Estrin The Cosinetic, Toiletry and Fragrance Assoc., Inc. 1625 Eye Street, N.W. Washington, D.C. 20006
Dear Norman;
X ashed our microscopist at the Stamford Research
Laboratories to comment on the "Final Report of CTPA
Talc Subcommittee" and sent a copy to Dr. J. Longfellow
who requested that I provide you with as many copies
as you deem useful.
'
I, therefore, am enclosing eight (B) copies of the
report. If more are needed, please let me know.
FDB: d t
F. D. Barbuscio
PLAINTIFFS EXHIBIT
WCD-195
LoGiudice/WCD/0242
; ' ' 1 " / 1 . .* i "
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STAMFORD RESEARCH LABORATORIES
*
RESEARCH SERVICE DEPARTMENT REPORT
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M r* T ra n k B a rb u s c io
from
M ic ro s c o p y
tMATER!Ai M e t h o d A s b e s t o s i n " a l e
ruAfiftF iw
( S46- 7145)
KiTRK reported by
I>,, W . D a v i e
., -
-4
dept. Consum er P ro d u c ts /
R0C:4 MO.
DATE REPORTED
.............
test
M i c r o s c o p i c a l k x a m i n a t i p n ____
date su b m itted 1-,,11-74 *
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NOTEBOOK REFERENCE g - 10931. U P . HQ.,111
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Introduction
;
.. i our comments on the data you have submitted concerning
.
the Dept; of Health, Education and Welfare's microscopical method
ior determining the amount of asbestos'in talc mayjheet he divided
into two parts; the test procedure itself and the 1 jections
raised;hy the CTPA subcommittee after a round-robin trial. , .
' " Test Pfocedvire
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` The method of sampling should he specified. ilicro-
rifflihs would probably he universally acceptable for powders
of allisizes and compositions,
j,
' jjv 2. Size of Sample.
j-
< j The test specifies a weight of one mg.;depend 1ng on
the aile-ranpe of the talc product, this may be too much or too
'
little ;to be truly representative,
3 . Criteria for a Fiber,
j
. ' , ' ' Two of these criteria (ii and iii) may become contra
dictory These criteria stipulate that fibers must have a length
of 5 micrometers or greater and a width of 5 micrometers or lesa.
Thus, J fiber 50 micrometers long and 8 micrometers wide (perfect
ly possible) would be in conflict, with itself! The: aspect ratio and
; the'length suffice to define the fiber dimensions} widt i - 1 Qot
be specified.
j
. . . ' ' 4 , Area to be iacamined.
.* .j . Assuming that one mg, is representative, the maximum
area suggested for examination is 648 sq. mm. This seems unneces
sarily 'large for routine microscopy, for it involves approximately
- lob traVerses of 50 fields each at 4002, or approximately 5000 field;
If the sample is well-dispersed, as specifieo, 10 equally-spaced
traverses, involving about 500 fields, should be adequate.
tso-i
LoGiudice/WCD/0243
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at;..* r.i
ts w p f . '-'i ' " * : : ' j r * .
52096--55
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General Comment
( * * **-!n r ' n r I 1 1,1J " M* * v<* a
, , . ! . :_* .
\ * >t ,
`.
' j Our Microscopy -Laboratory can perform this test,
however, we feel that the time required wouid probably b
one tp-tvo days per sample, if the figures are to- be meaning
ful. (
j
Objections by the CTFA Subcommittee
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III
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.' Objection Ho. 1,
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) Tills objection seems invalid, since the ttest re quires that both indices of refraction exhibited by- a fiber
be below 1.574 if the fiber is identified as chrysotile.
Also,,it seems unlikely that an experienced mineralogist
would ,confuse fibrous talc,or edgewise, platy talc, with
chry3 otile, as other optical characteristics, ,,1, detailed
morphology, interference color, change of relief on rotation,
' etc*, would usually be distinctive.
i
. ' ; Objections No, 2 , 3 , d, 5 , 6 and 7 .
J
* These all appear to be valid. > General Comment
I
* | Xt is quite obvious, from the disparity bf results
obtained in the round-robin trial, that the test, ks presently
designed, is not practical* Of the seven alternatives sug--
.. f-stedj No, 1, (Modified Optical Method) still seems to offer the best chance of successful application by the industry.
r ' ' t, ,
D. ;v. Davis
LoGiudice/WCD/0244