Document K6Gxvod1NXM7d3K5QLn9mMkx2
FILE NAME Talc TALC
DATE 1977 Feb 9
DOC TALC484
DOCUMENT DESCRIPTION Letter to Kaiser Gypsum from Pfizer RE
OSHA and Asbestos Standard
2-23-77 os
cc H. Berby
Wiborn
_ae OS,
4 7
ta A hte
MINERALS PIGMENTS METALS > PRIZEA INC 235 ( .42NU NEW YORK Y. 10017
DIVISION
1
February 9 1977
Buyin
Rick
Mr. W.E. Ousterman
Kaiser Gypsum 300 Lakeside Dr.
Oakland Ca. 94604
TALE
TALE TALE TALE
;
Dear Mr. Ousterman
C In recent months there has been increasing interest in
the subject of talc particularly with regard to the
.
nature and extent of its asbestos content
;
are one of our many valued talc
Since you
purchasers we feel
you should be aware of important information on this
subject
has The Occupational Safety and Health Administration OSHA
currently
in effect an asbestos standard which
scribes that
employees may
be
exposed
to
no
more
prethan
2 asbestos fibers per cubic centimeter of air for
hour weighted averag~ and to no more than 10
asbestos fibers per cubic centimeter at any time In
October 1975 OSHA proposed to lower the hour time-
weighted limit to 0.5 asbestos fibers per cc and 5
asbestos fibers per cc for any period not exceeding 15
minutes Very recently it has been reported that the
: ,
National Institute for Occupational Safety and Health has
recommended
the respective permitted exposure levels be
limited even further - to 0.1 asbestos fibers and 0.5
asbestos fibers per cc
October In its
1975 proposal OSHA defines
include chrysotile amosite crocidolit~
asbestos to
anthophyllite and actinolite and every protdruecmtolciotnetaining
any of these minerals OSHA also defines an asbestos
I
fiber as a particulate form of
which is
any of these minerals
;
longer than 5 micrometers and has a maximum
diameter of 5 micrometers and a length to width ratio of
at least 3 to 1
.
Fi y
HAR121604-3745 HAR121604-3745
2238
Zn
.
TALC TALC
The reason for the proposed revision of the
occupational exposure to asbestos is that
standard for
its several commercial forms has been
asbestos in
the production of not only asbestosis buatssa ocivaatreidetwyitohf
cancers and malignancies Because of the many unknown
factors including the variability individual
response to carcinogens and the absence of data to
establish a safe level OSHA has concluded that
exposure must be reduced
as
low as
is
feasible
employee
OSHA
proposes to hold bearings on the entire
until
those
hearings
and
subsequent
subject but deliberations
place there will continue to be
take
considerable uncertainty
Novertheless it is prudent for
any tale which might contain asy beosutroswofrikbeerrss whtioleavouisding
creating dust to the extent possible
procedures should be
Monitoring
trations under workingemcpolnoydeidtitoonsdetWehremriene dust concen-
dust control equipment or use of
appropriate
be
respirators should also
considered
You will
and worker
training programs
implemented
of
the
doubt
CSHA
wish
to
review
the
various
provisions
29 Code of standard for occupational exposure to asbestos
Federal Regulations 1910.1001 posed amendments
and the pro-
which appeared in the October 9 1975
issue of the Federal Register
Since we have no control over the
tale
products
in
your plant
it
conditions is
of use
of
to indicate the airborne fiber
not possible for us
concentrations which
could possibly we can provide
result from
information
your use of talc on the asbestiform
However
content of the talcs we supply
:
mineral
Pfizer research has developed the most
sensitive method available
accurate and
asbestos and
today of analyzing for
asbestiform minerals in tale This
based
on
step
scanning
ray
diffraction
method electron
diffraction and transmission electron
permits
identification
of
true
microscopy
chrysotile
|
levels of 0.5 and fibrous
asbestos at
at levels as low as
amphiboles such as tremolite
0.1 in the talc cation methods use
No other identifi
and scanning electron today including optical microscopy
as direct
microscopy are as sensitive and
ee
oe
ET
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