Document 7M6jBJgYd4ngmvzNoDRxVzbmE

FILE NAME Brakes BRK DATE 1970 DOC BRK102 DOCUMENT DESCRIPTION Journal Article - Exposure to Asbestos During Brake Maintenance i H Ann Occup Hyg Vol 13. p 1. Pergamon Press 1970. Printed in Great Britain i : RNER i Henri 4 dde ess t -llege traat ity of - tional iikum iikum ity of ; Broad- zienje Carlovo aba 8 School y PREFACE Exposure to Asbestos during brake and clutch maintenance THE PAPERS which follow were originally presented at a Conference held at the Central Office Ford Motor Co. Brentwood Essex on 26 March 1969. The Chairman of the Conference was Dr G. H. Channing Chief Medical Officer Ford of Britain who opened the by outlining the events which had led to the arranging of proceedings the Conference Publication of the proposed Asbestos . Regulations by the Department of Em- ployment and Productivity had raised queries within the motor industry as to whether maintenance and clutch activities brake maintenance activities both at the manufacturers premises premises and within the repair trade would come within the requirements of the Regulations There was a general desire that the subject should be investigated and any necessary remedial measures sought in advance of the legislation so that Dealers could be advised and servicing procedures modified where this might be necessary Investigations had been made by the Industrial Hygiene Units of the British Motor Corpora- tion and of Ford of Britain and their findings would be reported to the meeting These would be preceded by papers on the medical aspects of exposure to asbestos and later in the programme there would be papers indicating possible solutions to the problems involved - D. E. HICKISH 5.00 + a t- i Po ; i A 4 e re . a ISFORD . 10523 28 28 28 Ann Occup Hyg Vol 13. pp 17-21 Pergamon Press 1970. Printed in Great Britain EXPOSURE TO ASBESTOS DURING BRAKE mn MAINTENANCE er D. E. HICKISH and K. L. KNIGHT Medical Services Ford of Britain Brentwood Essex soma EXPOSURE DURING CAR SERVICING THERE is maintenance of passenger vehicle brakes involved at the manufacturers premises and therefore an investigation was carried out at the Service Bay of a Ford Main Dealer in the Greater London area This Dealer normally services 10-20 cars per day but blowing of brake shoes and drums is not included in all routine services It is the blowing procedure which is the subject of the study Air sampling was carried out using membrane filters the sampling and subsequent assessment being in accordance with the technique described in the Hygiene Standard for Chrysotile Asbestos Dust published by the British Occupational Hygiene Society 1968 Static samples were taken by the side of the car Fig ) and composite samples were also taken in the cloud during the blowing procedure continuing by the side of the car for the remainder of the sampling period Normally the mechanic takes care to blow the dust away from himself so this sampling procedure should overestimate exposure Two sampling periods of 45 minutes were used and during the first period one Cortina Estate and one Anglia Van received brake blow and wee during the second period one Cortina car was dealt with The results are shown in Table 1 oNew TABLE 1. ATMOSPHERE SAMPLES DURING CAR BRAKE SERVICE Location Location of samples 1st period Fibres 2nd period weighted : average By car Dust cloud then by car 1.12 1.71 1.42 3.62 1-25 2.55 An estimate of the daily exposure of the mechanic engaged on brake cleaning was obtained by a series of personal samples Fig 2 covering an entire workshift during which brake servicing was carried out on 11 vehicles The results are shown in Table 2 This paper was originally presented at a Conference on Exposure to Asbestos during Brake and Clutch Clutch Maintenance held at Brentwood Essex March 1969 17 tap ers ae 18 D. E. HICKISH and K. L. KNIGHT TABLE 2. PERSONAL SAMPLES DURING CAR BRAKE SERVICE SaSmapmlpele 123456 123456123456 123456 weighted average Concentration fibres 0.63 1.12 0-21 0.96 0.38 0-79 0.68 EXPOSURE DURING TRUCK SERVICING Maintenance of truck brakes involves a somewhat different type of operator exposure as the servicing is more complex and therefore the number of vehicles dealt with is less The larger size of wheels and drums on the other hand makes it difficult for the operator to avoid the dust cloud produced and personal exposure could be higher than that during car maintenance Further sampling was therefore carried out in a large fleet workshop with equipment similar to that used for the passenger car tests Static samples each of approximately 3 hr duration were collected during the morning and afternoon periods at three positions at the bay adjacent to the one at which brake cleaning was carried out at the next bay and in the centre of the garage Brakes were blown out during the morning but not during the afternoon results are given in Table 3 The TABLE 3. GENERAL ATMOSPHERE SAMPLES DURING TRUCK BRAKE SERVICE Location of sample Concentration fibres ww Adjacent bay 2 Bays away Centre of garage Morning Afternoon Morning Afternoon Morning Afternoon 0:28 ^' 0.07 , 0.17 0.07 0.49 0.11 Personal samples were obtained from two men man engaged on brake cleaning and the man engaged on clutch repair work at the adjacent bay The first period of 1.5-2 hr included the period of brake cleaning and the second period of approximately 5 hr represented the remainder of the shift The results are shown in Table 4 18 D. E. HICKISH and K. L. KNIGHT TABLE 2. PERSONAL SAMPLES DURING CAR BRAKE SERVICE Sample 1 23456 23456 23456 23456 23456 weighted average Concentration fibres 0.63 1.12 0-21 0.96 0.38 0.79 0-68 EXPOSURE DURING TRUCK SERVICING Maintenance of truck brakes involves a somewhat different type of operator exposure as the servicing is more complex and therefore the number of vehicles dealt with is less The larger size of wheels and drums on the other hand makes it difficult for the operator to avoid the dust cloud produced and personal exposure could be higher than that during car maintenance Further sampling was therefore carried in a large fleet workshop with equipment similar to that used for the passenger ocuatr tests Static samples each of approximately 3 hr duration were collected during the morning and afternoon periods at three positions at the bay adjacent to the one at which brake cleaning was carried out at the next bay and in the centre of the garage Brakes were blown out during the morning but not during the afternoon The results are given in Table 3 TABLE 3. GENERAL ATMOSPHERE SAMPLES DURING TRUCK BRAKE SERVICE Location Location of sample Concentration 4 fibres Adjacent bay 2 Bays away Centre of garage Morning Afternoon Morning Afternoon Morning Afternoon 282 ^' 0.07 0-17 0.07 0.49 0.11 Personal samples were obtained from two men man engaged on brake cleaning and the man engaged on clutch repair work at the adjacent bay The first period of 1.5-2 hr included the period of brake cleaning and the second period of approximately hr represented the remainder of the shift The results are shown in Table 4