Document 3JKdnkx0jx9L5oaEKYr41nBny
123 E.STIEGEL STREET, MANHEIM, PENN. 17545.
RaybestosJJVlanhattan
July 17, 1975
1. H. WEAVER C
CORPORATE DIRECTOR
ENVIRONMENTAL CONTROL
Mr. E. W. Drislane Executive Director Friction Materials Standards Bergen Mall Office Center E. 210, Route #4 Paramus, N. J. 07652
Institute,
Inc.
Dear Ed:
Please note the attached article that appeared in the May/June issue of Public Health Reports. The second page of the article contains a reprint of a booklet titled "Brake Repair Work Can Be Hazardous to Your Health."
This report, and others which have appeared recently, emphasize the need for responsible action on the part of friction materials manufacturers. Early this year, bulletins were sent to Grey-Rock and Raybestos distributors describing proper brake service procedures. However, I doubt very much that this information has gotten down to the mechanic level.
It has been suggested a small card containing abbreviated instructions be placed in every box containing automotive, bus, truck, and industrial brake linings manufactured by Raybestos-Manhattan. Tags probably would be used for roll lining. The following text is recommended:
- IMPORTANT
- AVOID EXPOSURE TO ASBESTOS DUST.
- DO NOT USE AIR HOSE WHEN PERFORMING BRAKE SERVICE WORK OR
FOR CLEANING WORK AREA.
- USE VACUUM CLEANING OR WET CLEANING METHODS SUCH AS DAMP
.
CLOTH OR OIL TREATED BRUSHES.
- DO NOT GRIND OR OTHERWISE MACHINE BRAKE LINING MATERIAL WITHOUT
ADEQUATE DUST EXHAUST AND COLLECTION EQUIPMENT.
I strongly recomnend all FMSI member companies adopt similar policy and procedure.
Very truly yours.
I. H. Weaver Corporate Director Environmental Control
dm
FMSI 06866
' ` The Hazards of Asbestos for Brake Mechanics
BARRV CASTLEMAN, LUCILLE A. CAMAROTA. ALBERT J. FRITSCH. SUSAN MAZZOCCHi, and ROBERT G. CRAWLEY
ASBESTOS is the generic name of a group of hydrated
magnesium silicate mineral fibers. There are two
groups of these minerals--serpentine (chrysotile) and
amphibole (amositc, crocidolite, anthophyllite,
tremolite, and actinolite).. Ninety-five percent of the
world's asbestos production is chrysotile.
Reports of epidemiologic and pathological studies
(1--4) reveal that occupational exposure to commercial
asbestos minerals enhances the likelihood of a number
of diseases--asbestosis and cancers of the lung, pleura,
peritoneum, larynx, and gastrointestinal tract. The
time from onset of exposure to the time of clinically ap
parent disease is usually more than 20 years. Cancer
from asbestos is not limited to workers who handle the
material. There are r also reports of pleural and
peritoneal mesothelioma (tumors rarely seen in the
general population) in persons with family, or
neighborhood, or indirect occupational exposure to
asbestos (4-- 7).
.
Mesothelioma was the cause of death of a man who
had rrgularly sanded vinyl asbestos floor tile (S). Under
simulated conditions of this man's work, a maximum
asbestos dust concentration of 1.3 fibers per ml (fibers
longer than 5 microns) was found in air samples passed
through membrane filters worn by a person sanding
vinyl asbestos (S). The type of asbestos now used in
domestic floor tile is chrysotile--the same as that used
in brake friction materials, according to the Asbestos
Information Association. A case of mesothelioma in a
brake mechanic has been reported (9).
Commercial friction materials used in the United
States for braking passenger cars and trucks contain an
average composition of 50 percent chrysotile by weight
(10). Asbestos has been used for brake drum linings,
disk pads, and clutch facings fob the past 50 years. Jacko and DuCharme (11) estimated that the United States annually uses 103 million pounds of asbestos for brake friction materials and 4.5 million pounds in automotive clutch friction materials.
In 1968 Lynch reported that because of the heat of friction caused by braking, almost all of the asbestos in brake linings is transformed to a nonfibrous mineral, and a small fraction of asbestos escapes as free fiber (12). Jacko and co-workers determined that vehicles in this country emit 158,000 pounds of asbestos per year, of which 11.2 percent is retailed in the brake and dis posed of during service (13).
Brake mechanics have low and intermittent exposure to asbestos. This exposure has been reported to be 0.79 fiber per ml time-weighted average (fibers longer than 5 microns), with peaks up to 7 fibers per ml when brake parts are being cleaned (14). The standard method for removing dust from brake parts is to blow it out with a
A/r. Castlcman, an environmental engineer, was with the Center for Science in the Public Interest when this paper was prepared; he is now with the Maryland Public Interest Research Group. Dr. Frilseh is director of the Center jor Science in the Pibtic Interest. Ms. Camarola is an occupational health nurse, District oj Columbia Department of Human Resources. Ms. iMazZ'nchi was a research associate. Environmental Cancer Research Project, Environmental Sciencrs Laboratory, Mount Swat School oj Medicine, Hew York City. Mr. Crawley is a sanitarian, llaltimore County Department oj Health.
Tearshect requests to Barry Castlcman, Maryland Public Interest Research Group, 3110 New Slain Dining Hall, University oj Maryland, College Park, Md. 20742.
254 Public Hoalth Reports
FMSI 06867
''tomprisscd air hose. In 1970 several reports (I I-IS) tleseiiberl the levels of exposure of brake mechanics to asbestos,' alternative friction materials, and specific changes in brake repair practices which would reduce the levels of exposure.
Baltimore and Washington Studies
In December 1972, the Baltimore County Department
of Health mailed a 1-pagc mimeographed circular to
about 130 establishments which provide brake repair
service. These businesses included new car and truck
dealerships, certified motor vehicle inspection stations,
and other concerns advertising brake repair as a
specialty. Some or the establishments initially con
tacted had cither gone out of business or replied that
they do not do brake repairs. The circular warned that
inhalation of the dust from brake cleaning could cause
serious diseases, including cancer, and advised
vacuuming brakes of accumulated dust. Additional
measures suggested were improved ventilation and the
use of face masks (19). Two student volunteers went to
100 of the places on the mailing list 4 month' later to
ask shop managers what methods they were using in
brake repair. A similar study was started in Washington, D.C., in
August 1973. This work was conducted by the Center
for Science in the Public Interest and the District of
Columbia Department of Human Resources. Of 186
brake service establishments initially contacted, 120
were followed up. Several new methods were tried in
order to improve the effectiveness of the warning. The
warning leaflet was more eye-catching and readable
than the paragraph-form sheet used in Baltimore; the
leaflets were handed out by an occupational health
nurse to the mechanics themselves--none were mailed;
and followup to ascertain the degree of effectiveness
was conducted by the same nurse who interviewed
the repair shop managers. The Washington study was
also featured in a local television program at the time
the leaflets were first handed out.
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BRAKE REPAIR WORK CAN BE
TO YCUR HEALTH
To assure that students trained in brake repair by public vocational schools would learn proper methods, health officials met with appropriate school officials in both locations. At the time they were contacted, school officials in Baltimore and Washington reported that the schools were teaching the "blow out" method of brake dust removal to the trainees.
The standard method of cleaning brakes is "blowing out" with a compressed air hose. In Baltimore, 65 per cent (65 per 100) of the brake repair establishments contacted were using this method at the time they received the warning circulars. In Washington, the figure was 91 percent (110 of 120). Most of the managers and workers interviewed had never heard _aboul the hazardous potential of brake dust. Predict ably, the responses ranged from annoyance to apprecia tion.
Of the 65 places in Baltimore initially blowing out brakes, 11 were using cither vacuum or wet brushing methods at the time of followup. Four others were still blowing out brakes, but had improved ventilation or provided dust masks, or both, to reduce workers' ex posures.
In Washington, only two establishments had changed to wet brushing, but none were vacuuming brakes. Four others provided face masks. Interestingly, two others decided to change brake shoes in all brake repairs, thereby simplifying the problem of dust removal and reducing the mechanics' exposures.
The degree of improvement, indexed by the percent-, age of establishments converting from blowing out brakes to safer techniques after a single warning, was 23 percent in Baltimore County and 7 percent in Washington. This disparity probably arises more from differences in the methods of the studies than from differences in the study groups.
It may be critically important to approach manage ment at the outset in order to enlist the cooperation needed to implement any changes in practice. A mechanic who is approached directly with a warning may simply disregard it. The mechanic might reason that if the dust were really dangerous, there would be a law requiring the use of preferred methods in brake repair. And the employer, if not asked to participate from the beginning, may well conclude that he need not be concerned with the matter. The failure to involve management may be the main reason why the Washington study produced less gratifying results than
the Baltimore study. Brake warning programs consisting merely of mailed
warning notices require little manpower, compared to other health programs. Also, the effort to implement safe techniques in public vocational schools is time well spent.
Conclusion
Over a 7-ycar period ending in 1976 ( 20,21), the b'.S. standard for time-averaged exposure to asbestos will have been reduced from 5 million particles per cubic
May-Juno 1975, Vol. 90. No. 3 255
FMSI 06868
.foot of air 10 2 fibers per ml (fibers longer than 5 microns). For asbestos textile plants, this reduction is about 15-fold {22). Present and scheduled standards claim only to protect workers against nsbestosis, the
i disease for which the dose-response relationship is most quantitatively known. The British standards for chrysotilc and amositc asbestos, which are comparable to the asbestos standard scheduled to take effect in the United Slates in 1976, do not purport to provide protec tion against increased risk of cancer (23,24). Previously studied cohorts of asbestos workers were exposed to time-averaged concentrations greater than 2 fibers per ml (fibers longer than 5 microns). Current studies of cohorts with time-averaged exposure on the order of 1 Tiber per ml (greater than 5 microns in length) may provide evidence of hazard at that level. In
view of alarming preliminary findings of pulmonary fibrosis in such a cohort, the National Institute of Oc cupational Safety and Health has suggested to the Department of Labor that consideration be given to
I further lowering of tbe*asbestos standard (25). The average brake mechanic is not aware of the
potential hazard of airborne brake dust. Nor is he quick to change time-hardened habits when warned, of dangers if he cannot feel their effects. Nonetheless, sub stantial reduction in asbestos exposures during brake repair can be achieved by simple changes in technique, with the use of equipment already available in most brake service establishments.
In view of the tendency of the accumulating literature to reveal cancer induction From asbestos at progressive ly lower levels of exposure, mechanics should be ad vised not to blow out brake parts and to use instead methods which create less airborne dust. The manufac turers of automotive friction materials could easily at tach a clear hazard warning to every item sold.
The limited success of both the Baltimore and Washington studies shows the limited efficacy of volun tary compliance with health warnings--the shop managers and the mechanics simply do not have the same regard for a warning that they have for a regula. tion. The margin of safety, if any, provided by the current asbestos standards has been sharply criticized as insufficient (26). While it is advisable that brake mechanics at least be warned of the potential hazard or their work, it is also apparent that blowing out brakes will be a common practice so long as health regulations permit it.
Rejercnccs
1. Cooper, \V. C., ct al.: Asbestos--tlie need for and feasibility of air
pollution controls. National Academy of Sciences, Washington,
DC., 1971.
.
2. SclikolT, I. J., Hammond, F.. C., and Clntrg, J.: Mortality ex
periences of asbestos insulation workers. In Proceedings of the
International Conference on Pneumoconiosis, Johannesburg,
1909, edited by !l. A. Shapiro. Oxford University Press,
Capetown, South Africa, 197U, pp. ISO--186.
3. Stell, P. M., and McGill, T.: Asbestos and laryngeal carcinoma.
Dinert 2: 416 -- 417, Aug. 25, 1973. /. Newhousc, M. I... anti Thompson, II.: Mesothelioma of the
pleura and pi ritoneum following exposure lo asbestos in the lamdon area. Hr J I ml Med 22. 261--269 (1965). 5. Lichen, J., and Pistawka. II.: Mesothelioma and adiestos ex posure. Arch Environ Health 14: 559-563 (1967). f. Wagner, J. O., Slngs. C. A., and Maiehand, P.: Diffuse pleural mesothelioma and asbestos exposure in the North Western Cape Province. Hr J Ind Med 17: 250 -- 271 (I960). 7. Dahpien, |\, Dahbert, A. F., and Min/, l.; Epidemiologic drr Plcuraincsothclioma. Yorlaufigcr Herirht uber 119 Falle aus drm Hamburger. Raum Prax Pneumol 23: 547--558 (1969). S. Murphy, R. L., cl al.: Floor tile installation ns a source of asbestos exposure. Am Rev Respir l)is 104: 576 -- 580, October 1971. 9. Sullivan, R. J., and Athanassiadis, V. C.: Preliminary air pollu tion survey of asbestos. National Air Pollution Control Ad ministration, APTD 69--27. Raleigh, N.G., 1969, p. 32. 10. Harwood, C.: Asbestos air pollution from the wear of brake linings. Illinois Institute of Technology Research Institute. Chicago, April 1972. 11. Jaeko. M CI., and DuCharme, R.T.: Brake emissions: emission measurements from brake and clutch linings from selected mobile sources. Environmental Protection Agency Report 68-04-1)020. Ann Arbor, 1973. ?2. Lynch, J.: litake lining decomposition products. J Air Pollut Control Assoc 18: 624-- S26 (1968). 73. Jacko, M. G., DuCharme, R. T., and joiners, J. H.: Brake and clutch emissions during vehicle operation. Paper presented at Society of Automotive Engineers Meeting, Detroit, May 1973. 14. Hickish, D. E., and Knight, K. L.: Exposure to asbestos during brake maintenance. Ann Occup Hyg 13: 17--21 (1970).
15. Hatch, D.: Possible alternatives to asbestos as a friction material. Ann Occup Hyg 13: 25--29 (1970).
16. Knight, K. L., and Hickish, D. E.: Investigations into alternative forms of control for dust generated during the cleaning of brake assemblies and drums. Ann Occup Hyg 13: 37--39 (1970).
17. Lee, G. L.: Removing dusts from brake assemblies during vehicle servicing--alternative cleaning methods. Ann Occup Hyg 13: 33-36 (1970).
IS. Bentley, M. L.: Control of the useuf asbestos-containing friction materials. Ann Occup Hyg 13: 31--32 (1970).
19. U S. Senate, Committee on Commerce: Toxic Substances Con trol Act of 1973. Hearings before the Environment Subcom mittee. Statement of B. Castlcnian. 93d Cong. 'U.S. Government Printing Office, Washington, D.C., 1973, pp. 117, 349 -- 350.
20. Guenther, G. C.: Emergency standard for exposure to asbestos dust. Federal Register, vol. 36, No. 234, Dec. 7, 1971, pp. 23207-23208.
2\. Guenther, G. C.: Standard for exposure to asbestos dust. Federal Register, vol. 37, No. 110, June 7, 1972, pp. 11318--14322.
22. Lynch, J. K., Ayer, H. E., and Johnson. D. L.: The in ' terrclationship of selected asbestos exposure indices. Am Ind Hyg
Assoc J 12: 598-604 (1970). 2?. Hygiene standard for chrysotilc asbestos dust. Ann Occup live
|1:`47-49 (1968).
24. Hygiene standards for airborne amositc asbestos dust. Ann Oc cup Hyg 16: 1 --5 (1973).
25. Key, M. M. : Reopening of asbestos standard. Memorandum toj. Slender, Assistant Secretary of Labor, Occupational Safety and I lealth Administration. Office of Technical Publications, National Institute for Occupational Safely and I lealth, Rockville, Md.. March 26, 1974.
2b. Gee, Ik, and Houhuys, A.: Action on asbestos. N Engl J Med 285: 1317-1318, Dec. 2, 1971.
255 Public Hoalth Reports
FMSI 06869
Preventive Health Care
Men with long experience as brake mechanics should have a physical ex amination at least once a year and preferably every six months. This should include a chest X-ray. The examining physician should be informed of the man's job and his exposure to asbestos.
<
j ,
If you have, or have had, exposure to |
asbestos, cigarette smoking is particu-
iarly bad. If yousmoke,stop.
|
.
'
How You fttay Contact Us
i
i t
j
Please let us know what action you are taking, what ideas you may have to
i
j !
offer, and what problems you encounter in following our suggestions for making
}
your workplace safer.
Contact:
I
Center for Science in the Public Interest 1779 Church Street, N.W. Washington, D. C. 20036
(202)332-6000
^
CAN BE TO YOUR HEALTH
District of Columbia Department of Human Resources Community Health and Hospital Administration Occupational and Employee Health Program' Center for Science in the Public Interest
FMSI 06870
What Are The Hazards?
Brake linings contain large amounts of asbestos fiber, a substance harmful to your body--
The risk of lung , cancer for people who smoke and work with asbestos is 92-times greater than for people who neithersmoke nor work with asbestos..
Among a number of groups of asbes tos workers,..one out'of .every, five deaths is due to lung cancer.
The risk of a serious lung disease, called asbesfosis, and cancer of other body sites is about the same for smokers and nonsmokers alike who work with asbestos.: .
At present, it is not known what level of exposure to asbestos, if any, is safe. Even a small amount may be dangerous in some circumstances.
Asbestos-related disease usually takes 20 to 30 years from the time of exposure to become evident. Work ing with asbestos for even a short time could result in asbestos-related disease later on.
Dos & Don'ts For Your Protection
To protect yourself and others in your
workplace against this hazardous sub
stance:
t
DON'T clean brake assemblies and;
drums- with an air hose.. (Fiber dusts -
generated by this method, are dangerr
ously high.)
DON'T brush or, by any other method,.
raise dust.
. - -
j
j
-I
DO vacuum out all the fiber you can.
DO wet-wash the parts with paintbrush
and kerosene.
..
-
-
.
DO use a protective mask when ex posure to asbestos dust cannot be avoided. Several companies manufac ture disposable masks, costing from $.50 to $1.50. For information on where these may be purchased locally, call the Center for Science in the Public Interest at (202) 332-6000.
fWSl0687A