Document pw63ddJ7bJnrgQm4Vk6mQakX
FILE NAME Talc TALC
DATE 1977 Feb 9
DOC TALC098
DOCUMENT DESCRIPTION Letter to Kaiser Gypsum from Pfizer RE
Talc & Asbestos
2-23-77 cc H. Berby ~~
;
R. Wiborn
uD
MINERALS PIGMENTS & METALS
PFIZER INC 235 C. 42ND ST NEW YORK Y. 10017
DIVISION
February 9 1977
:
.
Mr. W.E. Ousterman
Kaiser Gypsum 300 Lakeside Dr.
Oakland Ca.
94604
1
Rick
RicRick k Deck
Deck
. '
Wabern
TALE TALE TALE
C
Dear Mr. Ousterman In recent months there has been increasing interest in the subject of talc particularly with nature and extent of its asbestos conternetgardSin tc oe ty he ou
are one of our many valued talc purchasers we feel
syo uubjsehcotuld be aware of important information on this
The Occupational
Safety currently has in
and Health Administration effect an asbestos standard
OSHA
scribes
that employees may be
exposed
to
no
which premore than
2 asbestos fibers per cubic centimeter of air for
hour weighted average and to no more than 10
asbestos fibers per cubic centimeter at any time
In
October weighted
1975 limit
OSHA proposed to to 0.5 asbestos
lower
the
hour
time-
asbestos
fibers per cc and 5
fibers per cc for any period not
exceeding minutes Very recently it has been reported that the 15
rNeactoimomneanldeIdnstitute for Occupational Safety and Health has
limited even
respective permitted exposure further further - to 0.1 asbestos fibers
levels be and 0.5
the asbestos fibers per cc
October In its
1975
include
proposal OSHA defines asbestos to
chrysotile ' anthophyllite
amosite
brocidolite
tremolite
and actinolite and every product
any of these minerals
OSHA also defines
containing
fiber as a particulate form of
an asbestos
which is
any of these minerals
longer than 5 micrometers and has i
diameter of 5 micrometers and a
maximum
at least 3 to 1
length to width ratio of
.
ty
4 he .
A
HAR121604-3745 HAR121604-3745
2238
\
TALC TALC
as The reason for the
occupational
proposed revision
exposure to asbestos is
of the that
standard
for
its
the
several commercial
forms
has
been
asbestos in
production of not only
cancers and malignancies
asbestosis Because
associated with but a variety of
factors including the
of the many unknown
response to
variability individual
establish
a
carcinogens
safe
and
the
absence
of data
to
level OSHA has
exposure must be reduced low concluded that employee
proposes to hold
as is feasible
OSHA
until
those
hearings on the entire hearings and subsequent delibseurbajteicotns bu tt ake
place there will continue to be
considerable
uncertainty
Nevertheless it is prudent for
any talc which might contain
your workers while using
creating dust to the
asbestos fibers to avoid
extent possible procedures should be
Monitoring Monitoring
trations dust
under
employed to determine dust working conditions Where
concen-
control equipment or use of
appropriate
be considered and worker
respirators should also
You will no doubt wish to training programs implemented.
of the CSHA standard
review the various provisions
29
Code
of
Federal
for occupational exposure Regulations 1910.1001 and
to asbestos the
posed amendments which
issue
appeared in the October
pro-
of the Federal Register
9 1975
Since we have no control
tale products in
over the conditions of use of
to
indicate
the
your plant it airborne fiber
is
not possible
for us
could possibly result from
concentrations which
we can provide information your use of talc
However
content of the talcs
on the asbestiform mineral
we supply
:
Pfizer research has developed the
sensitive method available
most accurate and
asbestos and asbestiform
today of analyzing for
based on
minerals in tale This
step scanning diffraction and
ray
diffraction
method electron
permits
transmission identification
electron
microscopy
of true chrysotile asbestos
a lt evl ee ls velosf 0.5 and fibrous amphiboles such as at
cation
as low as 0.16 in the talc
methods use today including
No other tirdeemnotliiftie-
optical
and scanning electron
microscopy are as
microscopy
as direct
sensitive and
i
}
i
t }
|
HAR121604-3746
2239