Document baYn4eJpdD496DkjaGm35QnD0
FILE NAME Brakes BRK DATE 1976 July 8
DOC BRK260
DOCUMENT DESCRIPTION Memo RE Asbestos Exposure Associated With Automotive Brake Systems with Memo RE Sampling Results
INTERNAL
COR ESPONDENCE
COR ESPONDENCE
CORRESPONDENCE
CORRESPONDENCE
CALS
CALS
AND
AND
PLASTES
PLASTES PLASTES
PLASTES
PLASTES PLASTES
Mr. A. R. Clark
SA ends
ra
NSITUTE NSITUTE NSITUTE NSITUTE
NSITUTE
PLAST PLAST
PLAST
2331 CHARLESTON PP
BOX
2331
O. BOX
VIRGINIA CHARLESTON
CHARLESTON
WWE ESSTT CHARLESTON
VIRGINIA VIRGINIA
2255333300
Date
July 8 1976
Mr. J. H. Lloyd
Dr. R. J. Sexton Mr. F. Williams
Spagett
Asbestos
Associated With
Exposure Automotive BrakeSystems
At the request of the Plant Medical Department measurements of personnel
exposure to asbestos fibers during brake repair and inspection job tasks have been
made The spirit spirit of
while wearing cooperation maintenance
personnel samplers
Discussion of each
on the
during
of the
part of Mr. L. M. Hoffman was commendable
three types of job tasks involving brake job performances together with with results is
as follows
FIRST The right rear wheel of a pickup truck was removed for inspection It was
determined that new brake shoes were required the brake drum and replace the shoes He did
and
not
the mechanic
proceeded proceeded
respirator wear a respiratorrespirator respirator respirator respirator respirator as as a
to vacuua
need was
not apparent Time involved 24 minutes as sampling time Asbestos Asbestos
fiberfiber count was
0.4 fibers per ml of air with the threshold limit valve TLV being two fibers
greater than five micrometers in length
SECOND
The loft rear wheel was removed for inspection and the need for replacement
apparent compressed compressed was
At our request the mechanic wore a 3M respirator and used
air to clean the brake drum before changing the brake shoes
Significant quantities
of fine dust was generated which dispersed throughout the shop Elapsed time
five and sampling time was 19.5 minutes mmicrometers icrometers in length was 0.2 per
Asbestosfiber count ml of air There was
of fibers greater considerable dust
than collected collectedcolected
on the sample but less fibers possibly due to air dispersion
THIRD The right front disc brake was removed inspected
sampling time of two minutes
No air or vacuum was used
andreplaced during a
The results were 1.91.9
fibers per ml whichlikely indicates the
greatest with routine brake service to be the removal
and
for inspection when additional work is not required
exposure potentialassociated
replacement of the wheel
This factor factor is time related
We are of the opinion that even at the new fiber TLV there there is is generally generally generally generally generally generally generaly generaly general y
no problem with excessive exposure to asbestos in the automotive garage
Use
required the recently recently acquired reresspirpatoirs rators should be
vacuum capability should continue to be used on any special occasion where dust
levels
The 3M
of being excessive
Mr. Mr. Hoffman shouldshould be
there there are questions please
informed informed of
call
call
the results results of
these neasurements neasurements
and and if if
HH.. H.H.H.
Brazi
Brazi
a Me oh
Brazi
Brazi
H. H. Frazier Brazi
UCC 008857
Mr. J. F. Ballew Building 70-108A
INSTITUTE PLANT
Jr.
Ms. B. J. Mitchell Mr. J. G. Perkins Mr. F. Williams
April 6 1976 E.R. - Industrial Hygiene
You have asked that measurements be made of personnel exposure to airborne asbestos fibers while weighing dishes are being prepared for residue analyses Our records show that a similar measurement was made in Specifications Laboratory Room 205 March 10 1975 and was reported to be slightly above threshold limit value TLV
Three determinations nave recently been made by fiber filter samplers worn by employees while preparing sample dishes Analytical Laboratory Room 108. The results of these samplings follows
count on
in the
are as
Date
12/22/75 1/12/76 3/1/76
Employee
C. W. Devers D. DeLuca J. O. Good
Fiber Count air
4.9 47.6
7.7
We observed each of these samplings to be similar in technique
and airborne dust was not visible in either instance The TLV for asbes-
tos dust exposure is currently 5 fibers greater than 5 micrometers per cc of air as a time weighted average TWA and a ceiling value exceed 10 fibers greater than 5 micrometers in length As of July
the TLV will be reduced to 2 fibers as an OSHA allowable limit
in lengtn
not to
2 1976
This job task is only infrequently performed and it is unlikely that the TLV as TWA would ever be exceeded Our measurements however show that the ceiling level can be excessive We therefore recommend that work involving preparation of sample dishes with asbestos fibers be performed
within an exhaust ventilated hood
HHE HHE HHE : 18 18
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Prague Prague
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