Document 2q576M8BLvxJY8rMY2pmQpeB5
FILE NAME Brakes BRK
DATE 1986
DOC BRK098
DOCUMENT DESCRIPTION Journal Article - Asbestos Exposure in Motor Vehicle Repair in Hong Kong
J. Soc Occup Med 1986 36 104-106
Printed in Great Britain . -
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Asbestos Exposure in the Motor Vehicle Repair and
Servicing Industry in Hong Kong
INSTITUT DE L'AMIANTE
V. K. I. CHENG and F. J. O'KELLY
113 QUIST QUIST RUE SHERCROOKE - BURDAU 410
Occupational Health Division Labour Department Hong Kong
NILATR^ ALNILATR^ AL QUIDES QUIDES CANADA H3A 2018
recommended by the Asbestos Research Council
ARC 1971 was used Dust samples were collected on
millipore filters ofdiameter 25 mm and pore size 0-8 ...m using Casella pumps Filter sections were clearweitdh
magnification
Ftibrriesacwietwthiwithtihannaadssppeedccittarmraaetttiieoormaexgceendiingfexceeding ic...a3magnifcto mtwmagnwiiifitecaotihronnelenggthrgeraetateerrgreater
minimum of 200 fibres or 100 random fields and dust concentratiwoenrse detebyrthm e si tann dare d Ad RC
SoSommee 25 minute personal
samples at 1 litre
minute Bow rate minute 46 personal static samples at 2 litres
per minute Bow rate were collected The personal
samples were taken when the operator was either
were taken at breathing level within 5 metres of the work centre as portraying average exposure levels
repair
servicing
found in brake and clutch
cent chrysotile asbestos together with phenolic type
resins as binder and various other additives to affect
performance and wear and tear may cause fibre re-
jesse Recognition of an associated bealth hazard is
increasing and advice on prevention has been promul
gated by countries such as Australia and America but
assessment of occup haza ardt s fi romoasn besa tosl in
relevant
legislation it was oppotro t invu estn igaete
conditions in local garages A sample survey was under-
taken to get some measures of asbestos exposure as a
basis for determining health protection strategy
Method
Excluding very small concerns with less than 5 em-
ployees where brake and clutch work was unlikely to be
regular 12 garages were chosen at random from a list
of establishments registered with the local Factory
Inspectorate The largest was a bus servicing depot with 119 employees while the rest provided the usual repair
and servicing facilities for a variety of vehicles Of
these three had betwe 50eannd 100 and the remainder less than 50 employees
Visits were made to each garage to observe work
involving friction material and measure airborne dust
levels The membrane filter sampling method associ
-
ated with phase contrast optical microsopy PCM
104
Pra
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Findings
Asbestos material in clutch repairing was not encountered in any garage and it was explained that because of long life and the growing popularity of automatic fluid transmission gear systems its use was seldom necessary On the other hand brake work was a common activity in all estab anl d ati tens tionh wasmthe erefn oret focs ussed on this as likely to be the main source of possible asbestos exposure
Processes in brake work included cleaning dust from
the assembly removing old brake shoes separating
worn brake linings and fitting new ones to shoes with
possibly rivetting and bevelling the lining and reas-
sembling All processes were observed in bus servicing but in the other garages the use of factory made pads
for further machining Dust arising from the work was obviously a possible
source of asbestos It accumulated in the brake bousing
and was usually cleaned out by blowing with high
pressure air jet or brushing either of which methods could produce a visible dust cloud Sawing filing rivet-
another potesn ourt ce i of adul st In the largest estabalci omps arthmenmt e wasnalt lo-
cated to brake system maintenance and an extract fan was mou behn ind tht e work e benchd In the smaller garages there was no demarcation of working spaces and no arrang foredumsteconntrtol
Roug halh f tl he y ar angement
25 the
EXHIBIT NO
Betty Browning
Establishment
A B
D E
G H
:
I J K L
CA
brake cleaned
Air Sample
Type
Personal
StaticPersonal
Static
Personal
Static Personal Static Personal Static
Personal
Personal Static Personal Static Personal Static Personal
PersonalPersonal
Static
by jet CB brake
Work
Activity
x8JJJ
x8JJJ x8JJJ x8JJJ x8JJJ
/ CA
cleaned by
No. of
Samples
3
ANTM NYM N Y
ANTMN MNYMN N NY ANTMN MNYMN N NY ANTMN MNYMN N NY ANTMN MNYMN N NY ANTMN MNYMN N NY ANTMNMNYMNNNY ANTMN MNYMN N NY
Asbestos fibres ppeerr milliliare
_ Range
Mean
004-083
0-55
0-02-0-54 0-01
0-00-0-01
0-008
0-20-0-24
023
0-01-0-02 0-01-002 0-02 0-0 0-00-0-08
0-015
0-015
0-015 0-05 0-2
ANTMNYMNY 0-01-0-03 ANTMNMNYMNNNY
0-08-0-12
ANTMN MNYMN N NY
0-00-0-01
ANTMN MNYMN N NY
0-10-0-10
ANTMN MNYMN N NY
0-01-0-02
ANTMN MNYMN N NY
0040-12
ANTMN MNYMN N NY
0-03-0-03
ANTMN MNYMN N NY
0-16-0-28
ANTMNYMNY 0-08-0-12
ANTMN MNYMN N N Y
0-02-009
shing M bral pos mocuiane
oz
010
0-005 0-08 0-015 0-08 ec)
2
010 0-06
Sampling results
1. in Details of the number of samples takeean ch
the type of sample the work activity in the case of
personal samples and the asbestos fibre count are pre- sented in Table In many cases the fibre concentration
Discussion
Chrysotile can undergo degradation to forster-
iwteaosr a fibrsilo icatu e phs ase Lynch 1968 and it
temperaotriugirneally doubted that any fibres survived the high
generated in braking In addition to heat
this
confirmation survey however
of the
presence offibres
more significant than exact
levels tification at low levels
quan-
and recordings below ml were interpreted accordingly
0-1 fibre
Range
Mean
, ,
0-01-0-83
0-13
0-00-054 0-0-054
0-05
with mean 0-05 in the static Table II summarizes the asbestos levels in the
samples and shows a
various
a
mean
of
0-13
range fibre in
of
0-01
to
0-83
fibres
with
of 0-00 to 0-54 fibre personal samples and a range
a
of
samples
By occupational occupational exposure standards these fibre con-
centrations were comparatively low The highest aver-
age level of 0-13 fibre in personal samples and
the static sample average of 0-05 fibre indicated the time
weighed average exposure to be well within the occupa-
tional hygiene standard for chrysotile of 0.5
fibre at
to
.
Exposure such levels was unlikely be associated with a serious risk of pulmonary fibrosis and there
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106 OCCUPATIONAL MEDICINE 1986 VOL NO 3
appeared to be no record of such cases occurring in the
industry While asbestosis could be discounted as an
occupational hazard the same did not apply to the
carcinogenic risks The relationship of Threshold Limit
low levels diseases diseases other than fibrosis is uncertain and low levelsof exposure not necessarily guarantee
protection It was also for consideration that brake
debris is likely to contain an amount of small and
broken fibres
refleicntfiebwrdheerleevedlissedaesteerpmoitnenetdiablyisstnaontdanercdescsoaurnitl-y ing methods A link between garage work and cancer
has nobtutas yet been established by epidemiological a recently reported case of mesothelioma
Langer and McCaughey 1982 warna wiarnningg note
In answer to the pertinent question of what action
covered servic- was necessary in the circumstances it seemed prudent
to alert local industry to possible health hazard and aPdvrisae confotprriceovnc etnrteoilveofmeasures To this end a Code of
asbestos in motor
code included the advantage of using asbestos free friction material when possible the education of ex-
er
tee
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