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FILE NAME Brakes BRK DATE 1984 DOC BRK089 DOCUMENT DESCRIPTION Royal Health Commission Report on Health & Safety Matters from Asbestos Use in Ontario Barry Castleman's Brake Mechanic File ROM Document 89 = DATE Type of Document published report from journal published report from conference unpublished report unpublished presentation newspaper article letter or memorandum government report - ONTARIO government information booklet industry warning information book excerpt other Ontario Report of The Royal Commission on Matters of Health and Safety Arising from the Use of Asbestos in Ontario J. Stefan Dupr^' Chairman J. Fraser Mustard Commissioner Robert J. Uffen Commissioner Donald N. Dewees Director of Research John I. Laskin Legal Counsel Linda B. Kahn Executive ordinator 1984 Published by the Ontario Ministry of the Attorney General Printed by the Queen's Printer for Ontario Toronto 1984 ISBN for complete set of three volumes 0-7743-8508-1 ISBN for Volume One 0-7743-9151-0 ISBN for Volume Two 0-7743-9152-9 ISBN for Volume Three 0-7743-9153-7 Copies of the Report of The Royal Commission on Matters of Health and Safety Arising from the Use of Asbestos in Ontario are available from Ontario Ministry of Government Publications Services Branch Ontario Government Bookstore 880 Bay Street Toronto Ontario Services or Mail Order Service Canada M7A 1N8 Ontario Government Bookstore Telephone 965-2054 Information and Mail Order Service Telephone 416965-6015 Enquiries concerning the Report can be addressed to Ontario Ministry of the Attorney General Programme Analysis and Implementation Branch 18 King Street East 5th Floor Toronto Ontario Canada M5C 1C5 Telephone 965-7503 om ne smenot EO ecam cane re Le a um of 22 cc 4.7 cc with pling stations cluded that it TWA expoupply remain- le of Kirkland workforce over ntario Federa, and was the at the mill had city of 100,000 continual prob- e limit Ontario is the as an asbestos capacity of 300 1 workers The near Sharbot Ontario Minisewing asbestos at the potential where asbestos Canadian Talc sure in Ministry its air sampling d asbestos fibre 22 cc.59 sbestos and talc curring in the a al Commission on tos Deposits in the ne Ontario GeoloNatural Resources iene Occupational al Commission on Fixed Place Industry 361 1970s while average exposures by 1980 were generally within the 2 cc guideline approximately noted that in open mining workers may be protected from Bragg of 2 cc by enclosing the work stations on the equip- fibre levels in excess with the exception of ment that they operate He concluded that . . enclosures costing 5,000 to 10,000 per blasting csrteawtison would provide fibre levels at 0.1 cc except while entering would have to oapnedralteianvging the working area It is expected that blasters devices in the presence of high fibre levels In the wear personal protective levels can be reliably reduced milling operation it is unlikely that fibre 2 cc Even this level would require careful maintenance Bragg con- below protective devices could cluded that It is our estimation that only personal asbestos mills fibre levels below 2 cc for personnel in present provide have been developed and are used elsewhere in While milling processes render the fibre unfit for the uses to which Canadian the world water may in Australia trying to find ways to fibre is usually put Research is ongoing make this process compatible with the major uses of chrysotile asbestos G. Other Fixed Place Exposure In addition to mining and manufacturing Ontario fixed place to asbestos in brake repair in shipbuilding and workers may be exposed that occur in repair and in railroad equipment maintenance The exposures these activities will be reviewed below G.1 Asbestos Exposure During Brake Repair performance asbestos is widely used as a major component of automo- tive brCahrkyessotiinleboth disc pads and drum linings Depending on the type of content of the pad or lining will constitute from 25 to brake the asbestos Within the last few years cost- and 65 of the total productaswbeiegshtt os substitutes have become available However while some of the major brake manufacturers for disc brakes drum brake linings they are have recently begun to market asbestos This suggests that we available only in a limited number of applications the substitution of asbestos cannot in the immediate future rely tohen sole method of controlling the materials for asbestos in brakes as brake mechanics but instead must assume asbestos exposure received by that many brakes will continue to contain asbestos and Cost of Controlling Workplace Exposure to Asbestos Bragg The Technical Feasibility Fibres pp 84-85 Ibid p 85 and cae stilt at nad alittle 362 Chapter 6 Table 6.11 Summary of Asbestos Dust Levels in Ontario Asbestos and Talc Mines Fibres per Cubic Centimetre Year 1975 Average Area 1.4 Personal 3.8 1976 Area Personal 2.9 3.2 1977 Area Personal 3.3 4.9 1978 Area Personal 1.3 2.0 1979 Area Personal 0.8 2.4 1980 Area Personal 2.3 1.5 SOURCE Ontario Ministry of Labour data Range to 2.4 to 10.1 to 45.0 to 13.4 to 10.3 to 16.2 to 7.2 to 6.2 to 1.0 to 6.3 to 6.5 to 9.2 % Greater than 2 cc 18 18 22 22 22 22 2g 2g 0 NA m - Automo tion modifica extent of occu considerably 1 retain little t modification 1 drum brake li of brake wea wear debris w the brake hou A subs asbestos unde ing While it ing braking extent of this debris that is the high temp the asbestos i ticles.63 Simila Anderson et : and Bagg co separation of crystal structi lected by Als~- linings with p William from disc bra Barry Castlem Reports 90 ( Michael G. Ja from Brake ar NTIS 222- 64 Jeremiah R. tion Control a tos as a Frictio D.E. Hickish Annals of Occ Asbestos Em Society of Au Ronald L. Will Research 29 ( J. Alste D. W mospheric En 66 Michael G. Ja Wear 46 1978 See note 64 s Talc Mines % Greater than 2 cc 18 8 37 84 84 83 AN AN 30 NA +2 +2 Fixed Place Industry 363 Automotive mechanics may be exposed to brake dust during inspection modification removal or installation of brake linings However the extent of occupational exposure to asbestos in the servicing of disc brakes is considerably less than in the servicing of drum brakes because disc brakes retain little brake wear debris and disc pads seldom require manual modification to ensure a good fit During the inspection and installation of drum brake linings the exposure to asbestos may result from the removal of brake wear debris from the drum and back plates Historically brake wear debris was most frequently removed by directing compressed air into the brake housing to blow out the debris deposited in the drum.62 A substantial body of scientific literature has reported that the asbestos undergoes significant chemical and physical alteration during braking While it is generally agreed that the high temperature experienced during braking alters the asbestos there is still debate surrounding both the extent of this alteration and the identity and characteristics of the wear debris that is produced For example Jacko and DuCharme suggested that the high temperature experienced during vehicle braking caused 99.7 of the asbestos in the brake linings to be converted into inert harmless particles.63 Similar results were reported by Lynch Hatch Hickish and Knight Anderson et al and Williams and Muhlbaier And while Alste Watson and Bagg concluded that the major effect of braking appears to be the separation of bundles of fibres and reduction of average length without any crystal structure alteration Jacko has suggested that the wear debris collected by Alste Watson and Bagg may have resulted from studying brake linings with poor wear characteristics.66 Williams and Muhlbaier conducted 23 analyses of wear products from disc brakes and 24 from drum brakes They found that the average 62 Barry Castleman et al The Hazards of Asbestos for Brake Mechanics Public Health Reports 90 May 1975 254-256 Michael G. Jacko and Robert T. DuCharme Brake Emissions Emission Measurements from Brake and Clutch Linings from Selected Mobile Sources EPA Report 68-04-0020 NTIS 222-372 Southfield Michigan Bendix Research Labs March 1973 64 Jeremiah R. Lynch Brake Lining Decomposition Products Journal of the Air Pollu- tion Control Association 18 1968 824-826 D. Hatch Possible Alternatives to Asbestos as a Friction Material Annals of Occupational Hygiene 13 January 1970 25-29 D.E. Hickish and K.L. Knight Exposure to Asbestos During Brake Maintenance Annals of Occupational Hygiene 13.1 January 1970 17-21 A.E. Anderson et al Asbestos Emissions from Brake Dynamometer Tests SAE Paper 730549 presented at Society of Automotive Engineers Meeting Detroit Michigan 14-16 May 1973 and Ronald L. Williams and Jean L. Muhlbaier Asbestos Brake Emissions Environmental . Research 29 1982 70-82 J. Alste D. Watson and J. Bagg Airborne Asbestos in the Vicinity of a Freeway At- mospheric Environment 10 1976 583-589 Michael G. Jacko Physical and Chemical Changes of Organic Disc Pads in Service Wear 46 1978 163 67See note 64 supra presn 364 Chapter 6 asbestos content of the wear products was 0.029 which means that over 99.9 of the asbestos in the brake pad or shoe was transformed chemically or physically so that it was no longer an identifiable asbestos fibre Furthermore they found that less than % of all asbestos fibres observed were longer than 5 microns Rohl et al analyzed the wear debris from brake drums of automo- biles and found that in general only 3 to % by weight of the debris was recognizable asbestos implying that 94 to % of the debris was some other material They further determined that such asbestos as was present in the wear debris consisted predominantly of short fibres About % of the asbestos fibre in the debris was shorter than 3,750 Angstroms 0.375 microns in length so that a very small fraction perhaps % of these fibres would have been longer than 5 microns Thus researchers seem to be in agreement that brake wear produces debris that is % or less asbestos and that less than % of these asbestos fibres are longer than 5 microns Fibre levels experienced during removal of brake wear debris and reported by various authors are summarized in Table 6.12 Most of the readings were derived from optical measurements which means that nonasbestos fibres as well as asbestos fibres were counted Although the peak levels reported in a number of studies were high 87 cc these levels were realized only intermittently and for brief durations In contrast the samples taken over a longer period that included these peak exposures yielded timeweighted average fibre counts within the range of values found in other occupational exposures to asbestos in Ontario Furthermore since we concluded that asbestos constitutes a small fraction of the brake wear debris it is likely that many of the reported airborne fibres were not asbestos fibres and that the actual concentrations of asbestos fibres longer than 5 microns experienced during removal of wear debris were below the current 1 cc control limit on a weighted average basis Table 6.12 also shows airborne fibre levels experienced during modification of new brake linings Grinding and bevelling new brake linings to allow them to fit the brake drum do not subject the lining to the same high temperatures that are experienced during braking so physical and chemical alteration of asbestos is unlikely to occur Thus the exposure of mechanics during grinding of brake linings resembles more closely the exposure experience of employees engaged in friction products manufacture than it does the exposure of mechanics involved in removing brake wear debris from drums in that most fibres observed during grinding will be asbestos fibres Arthur N. Rohl et al Asbestos Exposure During Repair Environmental Research 12 1976 113 69 Ibid Table 2 p 117 Brake Lining Maintenance and Table 6.12 sho fibre release For inst ing personal samplin which ranged from 1 to 72.0 cc for bev found fibre levels r machining of brake 1 Considering the the mechanics who r taking proper precau centrations that exc exposure limit or the Medical studie and the incidence of greater prevalence of be expected in the ge Greenberg and Davi cases of mesotheliom has been suggested t workers parallels tha exposure to asbestos conducted which wo There are three first type encompass ments in Ontario doi service stations inde will rarely perform r William V. Lorimer et States The Mount Sir Letter from Mr. Arthu Safety Division Ontari August 1981 See for example M.A. Replacing Automobile 103 1973 1354-135 in the United States a Brake Lining Repair an final report to the U.S. 1983. Mimeographed Muriel L. Newhouse ar Following Exposure to Medicine 22 1965 261 Register 1967-68 Brit McDonald et al Epid Cancer 26 1970 914 ans that over d chemically bre Furtherpserved were of automoe debris was is was some ; was present bout 80 of troms 0.375 % of these rs seem to be less asbestos 15 15 microns r debris and Most of the ins that non- ugh the peak se levels were , the samples yielded time- und in other since we convear debris it bestos fibres an 5 microns urrent 1 cc during modiake linings to the same high and chemical of mechanics posure experi- 2 than it does r debris from sbestos fibres Maintenance and Fixed Place Industry 365 Table 6.12 shows that bevelling and grinding may cause considerable fibre release For instance Lorimer et al reported dust levels gathered during personal samplings of short duration analyzed by optical microscope which ranged from 1.7 to 7.0 cc for grinding truck brake linings and 23.7 to 72.0 cc for bevelling new linings The Ontario Ministry of Labour found fibre levels ranging from less than 0.1 cc to 15.6 cc during machining of brake linings at five brake relining shops in Ontario.71 Considering the fibre levels reported in these activities we believe that the mechanics who regularly grind and bevel brake linings without undertaking proper precautions may be exposed to airborne asbestos fibre concentrations that exceed either the current Ontario chrysotile short exposure limit or the TWA control limit or both Medical studies investigating the relationship between brake repair and the incidence of pulmonary disease have consistently demonstrated a greater prevalence of abnormalities among brake repair workers than would be expected in the general population As well Newhouse and Thompson Greenberg and Davies and A.D. McDonald et al have all documented cases of mesothelioma in brake repair and automotive mechanics While it has been suggested that the pattern of disease manifested in brake repair workers parallels that of workers employed in industries with occupational exposure to asbestos no epidemiological investigation of mortality has been conducted which would either support or refute this proposition There are three distinct types of brake repair facilities in Ontario The first type encompasses the vast majority of the estimated 11,000 establishments in Ontario doing automotive work Most of these shops are general service stations independent garages and franchised new car dealers that will rarely perform more than 8 to 10 brake jobs per week None of the William V. Lorimer et al Asbestos Exposure of Brake Repair Workers in the United States The Mount Sinai Journal of Medicine 43 May 1976 207-218 Letter from Mr. Arthur L. Gladstone Senior Policy Advisor Occupational Health and Safety Division Ontario Ministry of Labour to the Royal Commission on Asbestos 12 August 1981 See for example M.A. Boillat and M. Lob Risk of Asbestosis in Workers Employed in Replacing Automobile Brake Linings Schweizerische Medizinische Wochenschrift 103 1973 1354-1359 Lorimer et al Asbestos Exposure of Brake Repair Workers in the United States and William J. Nicholson Investigation of Health Hazards in Brake Lining Repair and Maintenance Workers Occupationally Exposed to Asbestos final report to the U.S. National Institute for Occupational Safety and Health April 1983. Mimeographed Muriel L. Newhouse and Hilda Thompson Mesothelioma of Pleura and Peritoneum Following Exposure to Asbestos in the London Area British Journal of Industrial Medicine 22 1965 261-269 Morris Greenberg and T.A. Lloyd Davies Mesothelioma Register 1967-68 British Journal of Industrial Medicine 31 1974 91-104 Alison D. McDonald et al Epidemiology of Primary Malignant Mesothelial Tumors in Canada Cancer 26 1970 914-919 OR a MI AIOE NIE UA REL ene re we 366 Chapter 6 sayeiq squeUW0s pjay-pueH synomjg Bunom Buimoiq yiys Uo dund awy snoy yIOM umojqg nq Wd 9y4e/q y bia ayeiq you WV ut 1n04 Bunp Sa421g U! you Bung A/AWgUML VML ReferenceReferenceReference OperationOperationOperation yead by Number Number Number ead = on trucks Wererner eiqiy (9/4) go'c 89600 8L00 cleaning trucks GE'Sv8'0 0748 cg'0 91 0 Personal &v 0 men cb 8r go 6c-99 -07 -F0 -40 OCL-L OL i 450 -LI -c0 Ee 300 UONFEAVIUD terion. eouayWayesg ejdwespoued nulw){se 06 OSP ool oor - garage garage centre centre so0809 09 "soaS OL-c OL- OL-z *S9S SUIL Ol-z Gin Looe) 7 Personal Ma} Of- (panuos) BungF192LZL'9 ; (Z) (z) Mitra (p) (g)} z1 9 adjacentadjacentbay e Bumojig a1geL Area wo (G) secs oansodxy Buynp Woy (Z) 4 "4 4 er sojeqsy uones7/pyr equin) cloud operation operation 09-OL pnop Lorimer Wosy ) dfursotm 2-10 apts isnp 3 4e9 3-5 from from operation oe yo a al.d {z) from operation 2-10 10-20 (INd/Wv) Personal 5-10 Aq uo Buijdwes operationperation few secs |2UOSIadg dust jeuosiad 10-75 from from 2 few easy ealy eel operation Background 10-75 uonesdg lings ino Buieslo Buimorg isnp a4e1g syoUnaOy Beveling Bevling brakes new lin gs linings Z eBese6 Burmoig Background ft ysnp pasn sayeiq mau Background ft Buimoyg Bulpus yond) Bulyjarg sBuiuly equsejy YspidIH pue ev{6iuy wBiuypue QusPystH a4oeH Jaui07) ple ia ce\cphenastir! yeod go. OL LL ool 610 - 1-@0 rez0. "S208 SUIW O1-Z M2} OL- woly (g) (v) 34 33. . 1 G/-OL 09-OL 08'-g8 (9) (OL) c) punciByoeg uonesado leuosedpunos6y9egjeuosipun9osB4y9e snp pasn sayeiq mou Buimoig Burpurid YON Buijeag sBuiuy 0.2- Place Industry 367 OZL-E(Q6L) ayeig 6Z-G7auipay jo jo Sjuewoy Lig, OZ6L Buieaig jeusnor ZL en auiBAy aur Asenur) jeurs Yoveasy jevondsQ jeuamonAz e pajei9Uad)Bung L-<LuNOp =/48qg - yead aulBAY a,y jo 9E zo eg -EL -0 aouejIW UONFAIJBUOD aoueqiy jeuondz3Q eye1g ejdwespoued 8- {penuos) Table souealW Z19 Buling Exposure e1geL einsodx] " (Z) Method Concetraion Sampling Location Location Concetraion operation WO -Yy ( <) YW SOAneUsary <-L 2b sfeuy ISN SES ,eday _, JOJ "6E-7E pauy jo pue e jONUOD HOLEL ayi ut JO sjeuy Maintec ayeig SWO ALs:enEuLr) ,"jeuayw siapyonry Buiury Mainteance Heday BANEUJAIY aulGApyuonvy aye7g aye2g ou Fibre OU! e& Jo se Bung / 1.3- TWA Peak Coments jo 0} -aBerae 0- YSsjeuy Peak "QLZ-20Z soregsy, 2 ,/SuiN4Ig (9Z61 1Z-Zt 3G Je 7] 18 y " 18 payBim-awn aqisod, JaWUOT] sump sump ysniq Jaye ysniq < pue (026k Pue PUR JYOH Ajp Aip A Hygiene Brake Asbetos Ocupationl During Brake MainteanceMainteac Anals, of Ocupational During OcupationlAnals Ocupationl the for Alternative Maintenace 7 Dust Generated Generated During Hygien Ocupationlof United Repair Brake Repair 368 Chapter 6 here are organized The second type of shop is the automotive employees exclusively in brake repair work shops frequently franchised specializing of and one or two other specialities The majority or brake rienpatihirs type of shop are also not organized Shops of this type The exposure of employees week complete on average in excess of 50 brake jobs per in these shops is greater than in the shops of the first type simply mechanics third type of shop is the because of the higher frequency of operations The for the large automotive fleets This includes the shops service department and urban transit operators In a large shop of major trucking companies where the workers of this type there may be a separate brake department deal only with brakes It is in such shops that it is likely that a substantial volume of bevelling and grinding of new brake linings will be performed machined Brake jobs involving the installation of new brake linings in the first of shops will seldom require manual modification of the linings two types vehicles and small trucks under- This is because for virtually all passenger brake repair in these shops machined linings i.e. linings which going dimensions of the brake drum are manufactured to conform to the exact are available and only infrequently will manual modification be required to fit the relined shoe to the drum For those operations using it would be unlikely that more than % of all relined brake shoes linings drum Thus the major op- would require manual modifications to fit the However there is still portunity for exposure to brake dust is removed potential for exposure to brake wear debris in these shops While machined brake linings are available for the larger vehicles in the third type of shop some fleet owners stock only one over- rseizpeadirberdake lining size and alter the linings to meet the specific size require- ments of the brake drums being repaired In these shops we would expect that a number of employees would engage continuously in grinding and bevelling of drum brake linings Mechanics repairing drum brakes may be protected from dust expo- in two ways A high efficiency particulate air HEPA filtered vacuum sure debris from brakes instead of blowing the may be used to remove wear methods may be used debris out with an air hose Alternatively wet cleaning the drum and assembly with a damp cloth or by directing epirtehsesrurbiyzewdipwiantger or brake shoe spray into the drum Bragg discussed the use of an inexpensive spray with a bowl to collect the contaminated liquid Brake washer systems including the liquid spray hose and trolley are available for about 200.74 The Technical Feasibility and Cost of Controlling Workplace Exposure to Asbestos Bragg Fibres p 90 evema! evrpmnie G.2 SH Shipbuil workers may t War II firepi sprayed in bui surfaces and c those applying the spraying a ' was installed posures but t discussed in C work in Onta stantially durir 1943-1944 We was exposed to of its peak lev cluded the co British and A Railroad source of wor locomotives w to the insulati 10. Construct asbestos insula have to be r around the ins boiler and pip All workers in asbestos We might be of t dealing with b See Chapters been found in have not foun Ontario Martin St Population of Mimeographe Disease Amo 1981 39-44