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FILE NAME Brakes BRK DATE 1987 Aug DOC BRK158 DOCUMENT DESCRIPTION NIOSH Report - Evaluation of Brake Drum Service Controls Castleman File Brake Mechanic File | w = with cover letter or memo If DATE = 0 undated ROM Document # brake 158 DATE 1987 1987 published _ article _ letter from journal published presentation from conference published government report // / government inspection results unpublished or internal report unpublished presentation from conference newspaper article letter |. memorandum industry warning labels industry sales literature industry recommended practices agenda minutes attendee list ___ legal filing of defense legal filing of plaintiff legal deposition __ legal testimony of The OKE 16 16:00:13 20012001 ty DEPTH SURVEY REPORT EVALUATION OF BRAKE DRUM SERVICE CONTROLS " United States Postal Service Vehicle Maintenance Facility Nashville Tennessee REPORT WRITTEN BY Frank W. Godbey Thomas C. Cooper John W. Sheehy Ph.D. Dennis M. O'Brien Ph.D. Harold D. Van Wagenen James D. McGlothlin William F. Todd REPORT DATE August 1987 REPORT NO ECTB 152-20b NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH Division of Physical Sciences and Engineering Engineering Control Technology Branch 4676 Columbia Parkway Cincinnati Ohio 45226 The h 16 16:00:13 16:00:116:030:13 2001 P. PLANT SURVEYED SIC CODE SURVEY DATE SURVEY CONDUCTED BY EMPLOYER REPRESENTATIVES CONTACTED EMPLOYEE REPRESENTATIVES CONTACTED ANALYTICAL WORK PERFORMED BY United States Postal Service Vehicle Maintenance Facility 707 Chestnut Street Nashville Tennessee 37203 4311 October 27-30 1986 Frank W. Godbey Thomas C. Cooper Harold D. Van Wagenen Dennis M. O'Brien Charles Harvey Fleet Operations Manager 742-0207 Robert Hart Supervisor Vehicle Maintenance 742-0203 James C. Hollingsworth Nashville Local American Postal Workers Chief Steward Union AFL Eugenia Shtrom PEI and formerly Utah Biomedical Laboratory Data Chem Testing Tit Tit 16 16:00:316:300:33 201 = I. INTRODUCTION The National Institute for Occupational Safety and Health NIOSH is the primary Federal agency engaged in occupational safety and health research Located in the Department of Health and Human Services formerly Department of Health Education and Wolfare it was octabliched by the Occupational Safety and Health Act of 1970. This legislation mandated NIOSH to conduct a number of research and education programs separate from the standard setting and enforcement functions of the Occupational Safety and Health Administration OSHA in the Department of Labor An important area of NIOSH research deals with method for controlling controlling occupational occupational exposure to potential chemical and physical hazards to cafe levels The Engineering Control Technology ECTB of the Division of Physical Sciences and Engineering has been lead within NIOSH to study the engineering aspects of hazard control Branch given the Since 1976 ECTB has conducted a number of assessments of health hazard control technology on the basis of industry common industrial process or specific control techniques Examples of these completed studies include the foundry industry various chemical manufacturing or processing operations spray painting and the recirculation of exhaust air The objective of each of these studies has been to evaluate and document effective control techniques for potential health hazards in the industry interest and to create a more general awareness of the or process of need for or availability of an effective system of hazard control measures These studies involve surveys are conducted a number of phacoc to select plants or Initially a oorioc of walk processes with effective and through potentially transferable control concepts or techniques Next depth surveys are conducted to determine both the control parameters and the effectiveness of these controls The reports from these then used as a basis for preparing technical reports and depth surveys journal articles are on effective hazard control measures Ultimately the information from these research activities builds the data base of publicly available information on hazard control techniques for use by health professionals who are responsible for preventing occupational illness and injury Background Asbestos is found in motor vehicle brake materials Recognition of asbestos carcinogenic properties has currently resulted in substitution of less toxic fibers number for come brake materials of brakes This study is However concerned acbertor with the in chill in large control of asbestos exposures to workers who are required to repair motor vehicle brakes Dubrow and Wegman published a research and control priority assessment of occupational carcinogen1s Their objective was to identify occupations with potentially high cancer risk by combining the results of 12 major occupational disease surveillance studies and to make recommendations concerning priorities for occupational cancer research and control on the basis of the results of this analysis in conjunction with other available opidemiologic industrial hygiene toxicologic and employment data basis of the principles outlined in their paper some priorities for On the research Tue beh 16 16:01:116:301:13 21101 a , P. D and control clearly stood out Their results pointed to the investigation and control of occupational exposure to asbestos as the number one priority in occupational cancer research and control In this situation where occupational disease surveillance studies point to a likely problem with a known carcinogenic agent the priority should be placed on industrial hygiene investigations of asbestos exposure in the suspect occupations If likely exposure is found control measures should be developed and instituted ' There are frequent asbestos exposures during brake repair in the vehicle maintenance work force NIOSH in the National Occupational Exposure Survey estimates that a work force of 151,000 brake mechanics and garage workers in the U.S. are potentially exposed to asbestos Other estimates run as high as 900,000 workers being potentially exposed in brake servicin3g A study of brake service operations was needed because of the following known carcinogenic potential of asbestos a large number of workers are the potentially exposed primarily small businesses perform brake servicing and lack resources to evaluate control devices and the general lack of information on the effectiveness of currently available control devices Therefore the Engineering Control Technology Branch undertook this study The primary objective of this control technology assessment is to determine the effectiveness of various control techniques used during brake repair and the transfer of the documented information to the appropriate individuals in industry labor academia and the government i.e. industrial hygienists safety engineers OSHA EPA etc. A secondary objective of this assessment is to determine if additional research is needed Description of Brake Servicing Operations Repair facilities follow the same basic servicing procedures The vehicle is driven into a repair stall or bay for a brake system examination Pending repairs the wheels are elevated removed and the brakes inspected Loose dust is cleaned from the drums and brake assemblies by vacuuming wet or dry brushing using compressed air or a combination of these methods Parts are then replaced or repaired as needed and the brake system is reassembled and adjusted The vehicle is then driven to check and adjustment in the final phase of the servicing operation for proper fit The brake repairman and other service personnel potentially exposed to asbestos dust during and removal If the normal dust buildup inside the removed and disposed of in a controlled manner in the garage area are following the brake drum drum and brake assembly is this hazard can be minimized Site Selection Preliminary surveys were conducted at 10 sites using a variety of control techniques These site visits were conducted to observe the control techniques in use and to select sites for detailed sampling studies Sites were selected primarily from fleet garages to control for variables such as vehicle type use and maintenance practice and on the physical size of the garage Selection of sites was made as judiciously as possible based on criteria including ChoPk 16:00 16:00 16:00 16:00 P. a The type of control technique being used at that site b The type and quantity of vehicles available for brake repair Good work practices and a sound management approach were fundamental to the existence of suitable conditions for study Health Effects The health significance of the inhalation of chrysotile asbestos fibers in auto In a repair workers includes detailed examination of asbestosis lung cancer and mesothelio 4m -a 8 00 union motor vehicle maintenance workorc in Now York City with 10 or more years of shop work 29 had decreased vital capacity the percentage increased with age and most markedly after 20 years from the onset of auto work many of the workers examined showed signa consistent with asbestosis with observed changes noted in chest rays and indication of restrictive pulmonary function The prevalence of these changes was significantly higher after 20 years exposure a result expected after occupational exposure to asbesto8s Many of the asbestos fibers originally present in the unused brake shoe chomically degrade due to the high temperature asbestos fibers exist in automobile brake dust encountered in use in various states of Chrysotile deformation Unlike chrysotile the health effects of exposure to forsterite a deformation product of chrysotile or to transition series fibers chrysotile with altered crystalline structures are not well documented In studies by Davis and Coniam and Koshi in which fibers of chrysotile forsterite and forsterite were injected into the pleural and peritoneal cavities of mice the results suggested varying dogrocs of toxic otfocts Fibor implantation animal studios conducted by Pott et 11,12 and Davis et 13 suggest that the morphology and size of a fiber regardless of fiber type are responsible for its carcinogenicity Likewise Stanton et al suggests that fibers less than 1.5 um in diameter and greater than 8 um in producing pleural sarcomas These studies in length pose the greatest tend to suggest that the risk physical morphology size dimensions and to a lesser degree chemical and surface characteristics of a fiber are the determining factors for inducing a biological effect The precise fiber dimensional characteristics required for these observed pathologic responses have been difficult to determine experimentally because of the difficulties encountered in producing fibers of specific size dimensions Because of the observed health effects in auto repair a clearly identified effect level for asbestos it exposure to brake dust which may contain asbestos workers and the is important to lack of minimize The two sources of occpuational exposure are 1 the NIOSH Recommended Exposure of Labor OSHA Permissible Exposure Limit criteria considered in this study Limit REL and 2 the Department PEL NIOSH recommends that employee exposure feasible limit due to the carcinogenic to asbestos be nature of this reduced to substance the lowest The NIOSH TH 00 1 St P. REL published in 1976 is 0.1 fibers greater than 5 ...m in length per cubic centimeter cc 15 NIOSH submitted an update on the recommended asbestos criteria at proposed making hearings for asbestos in June 1984. position is summarized below The the OSHA NIOSH The carcinogenic potential of asbestos is no longer in doubt however There is some uncertainty shont the toxicological and morphological properties which determine the carcinogenic potency of various fibers NIOSH believes that on the basis of available information there is no scientific basis for differentiating between asbestos fiber types for regulatory purposes Data available to date provide no evidence for the existence of a threshold level Virtually all levels of asbestos exposure studied to date demonstrated -- -- excess of asbestos disease NIOSH continues to believe that both asbestos and smoking are independently capable of increasing the risk of lung cancer mortality When exposure to both occurs the combined effect with respect to lung cancer appears to be multiplicative rather than additive From the evidence presented we of causing lung cancer may and conclude that mesothelioma asbestos is independent a carcinogen of smoking capable NIOSH has recommended that asbestos be controlled to the lowest detectable limit It is our contention that there is no safe concentration of exposure will not to asbestos Any standard no ensure absolute protection for matter how low the concentration all workers from developing cancer as a result of their occupational exposure However lower exposures carry lower risks Since the only widely available method NIOSH Method 1400 17 is able to achieve intralaboratory accuracy of 12.8 RSD at an exposure limit of 0.1 cc 100,000 min a 400 liter sample NIOSH and others have recommended an exposure limit REL of 0.1 ce for asbestos based on hour weighted average concentrations While this is a well undorctood practico wo can not find compolling arguments to prevent a recommendation based on alternative sampling periods In fact such an approach may provide more protection than an hour based sampling period that allows short exposures 6 or 10 times greater than the hour exposure limito being considered by OSHA Furthermore since there is uncertainty rogarding the cumulativo doco roquirod to initiato dicoaco it cooms reasonable to make overy attempt to control exposures to as narrow a range of concentrations as possible One way to accomplish this is to restrict the period over which workplace concentrations can be averaged Perconal campling pumpe are available with flow ratoc up to 3.5 1pm which would allow a sampling time of two house or less Finally we still believe that there are occasions such as mixed fiber exposures where fiber specificity is necessary Therefore we recommend the use of electron microscopy in the event of process or product modificatioinn mixed fiber exposures or when there are other reasons for characterization of fiber type and morphology A M 8 Th 16:00:13 16:00:13 16:00:13 PHBR1 H. As noted the occupational exposure criteria - the NIOSH REL and the OSHA PEL- are method based on the readily available Phase This method has inherent limitations Contrast based on Microscopy analytical the physics of the optical microscope and upon the ability of discriminate the specified length to width The minimum diameter routinely observed is the counters to reliably ratin in a complex sample matrix on the order of 0.5 ...m The NIOSH 7400 method stipulates with a length to width ratio that only of either fibers longer than 1 A rules or 5 ...m be counted 1 B rules The A rules use the same aspect ratio as the current OSHA standard and thus have the advantage of relating to current and historical compliance data They have the potential disadvantage of counting particles that may or may not be fibers In the present study TEM offers the advantage of being able to determine the actual dimensions of all fibers that were counted and thus to dillerentiate the numbers of fibers with various length to width ratios A coarse analysis of this data indicates that fiber counts using NIOSH A 7400 and 7400 counting rules would differ by less than 15 Another concern is that asbestos fibrils as small as 0.07 um in diameter and less than 1 ...m in length are visible only with electron microscopy These fibrils present constitute a significant and in brake dust Thus PCM in variable counting proportion of the total only optically visible fibers particles may not bea good indicator of the total fibers present Controversy over the health affect of small fibers and thus what sizes of fibers should be counted Adds Further ambiguity he thin aran On June 20 1986 OSHA issued a revised standard PEL which reduced the PCM level to 0.3 6/00 00 an 8 hour timo voighted average TWA oxpoques It aloo set an action level of 0.1 cc that triggers worker training medical monitoring and other requirements The new standard dues not set a ceiling or short exposure limit II PLANT AND PROCESS DESCRIPTION Facility Description The United States Post Office Maintenance Garage in Nashville services all the Federal postal vehicles for the Sectional Center District of Tennessee This involves 575 vehicles whose city routes cover nearly half of the state Records vehicle on all these Postal vehicles are kept by computer has a minimum of two complete inspections If the Each year each computer record shows more than 500 miles per month usage then the yearly scheduled inspections are increased from 2 to 3. An average city mail delivery route is within a 20-30 mile range with a minimum of 250-400 mail stops The local Postmaster keeps track of vehicle mileage and may shift vehicles from route to route so that total vehicle mileage on all routes stay approximately the same All the garage shop personnel are members of the American Postal Workers Union CIO In the entire Sectional Center District facility services the following the Nashville vehicle maintenance ane te h BASIDIRT BASIDIRT 13 201 ra P. 1 Five hundred and seventy Jeep delivery vehicles - This category | includes 1/4 and 1/2 ton special vehicles Jeep engines and chassis but a larger enclosure than the standard Jeep delivery unit Eighty to 85 of the 575 vehicles are the AM General Post Office delivery vehicle type and the remainder are special vehicles Most of the delivery cylinder - Jeeps and all the remainder the 1/4 and 1/2 have cylinder Ton units engines have Most of the delivery Jeeps have 13 or 14 wheels and 10 long brake shoes Jeep delivery vehicles have the following specifications a Manufacturer - AM General formerly American Motors Corporation b Model c Model year - 1973 to 1986 d Brake Type - All four wheels equipped with drum brakes e Tires - Bias Ply f Vehicle Weight - 2,310 pounds 8 Transmission - Automatic < h Differential - limited slip rear wheel drive 2 Thirteen seven International trucks disc brakes all four wheels 3 Three Mack and two White tractors drum brakes all four wheels A Seven trailers The one garage is staffed with nine mechanics one lead mechanic four garagemen body man and two supervisors Six mechanics work from 6:00 am.to 2:30 p.m. and four mechanics work from 9:30 8.m. Lu 6:00 p.m. with all 10 mechanics on duty from 9:30 a.m. to 2:30 p.m. The garage building sides face East and west and is 202 feet long with a working area of 64 by ill feet and a ceiling height of 20 feet There are seven bay doors on each side fost wide A plan nf the with each door approximately feet high and working area is shown in Figure 1 When the garage was opened in 1979-80 building heat was provided by a bank of six Blootrioul hostore oquipped with small fans anapended in a row on each side of the garage 12 heaters Because these units were expensive to operate they are no longer used In their place four fired unit heaters were installed at each corner of the garage There These is an under hose and pipe are located in the floor by the system to remove auto doore of the 14 bays exhaust Six of fumes the hays The + 16 16:00:116:03 0:13 2001 10 are equipped with hydraulic lifts both front and rear of each vohiele so they can work on twelve elevated vehicles at the same time Each bay has a working with of 13 feel Numerous electrical cables ure suspended from above alongside the bay These are extended for use to power the numerous power tools the mechanics use Much of the repair work is done with the mechanic standing under the elevated vehicle Ventilation of the garage is minimal There is a series of mounted fans on each side of the garage These are operated in summer to remove hot air from under the roof area In the cooler months these fans are not used and the inlet dampers are kept closed There is no provision for providing fresh heated air from the outside When the 14 bay doors can be left open during mild weather they provide a lot of useful ventilation During colder weather the garage air temperature is kept at 60-65 at the mechanics working level Process and Equipment Description This facility is currently replacing asbestos brake shoes with the nonasbestos type when venicie brakes facility concentrated on of control effectiveness are repaired our control evaluation at this Jeep vehicle maintenance to determine the variability in the same model vehicle during 10 separate vehicle ; brake repair or inspections A 760 brake washer accembly unit Kloor Flo Model LW 22 Rollabout had been used to control months prior to potential asbestos exposure our survey Figure 2 shows at this facility for several this washer unit Although the unit was not evaluated in use on any type of vehicles except jeeps supervision reported good results when using this ac wall Tho portable washer mover aasily to the unit on the larger vehicles brake location A water solution GreasofffiNo. 19 recirculates through a flexible tube and brush to flood parts clean The upper tray raises to the work area to hold small parts ready for reassembly and to catch the solution A pump in this machine pulls the solution through a nylon filter and then pumps the filtered solution through a flexible tube and out between the bristles of the brush allowing a gentle flooding of the brake assembly area to wash down any dust and perform the necessary cleaning The solution is returned to the bottom tank where it is recirculated The upper tray is removable to permit use of the bottom tank for cleaning brakes on larger vehicles One gallon of Greasofffi No. 19 a liquid concentrate mixed with five gallons of water and is used to clean 40 to 50 wheels before it needs to be dicearded Four gallons of Groacoff No. 19 co t 75 Greasoff No. 19 contains the following hazardous ingredients less than % by weight sodium metasilicate a highly alkaline compound pH 12.4 and less than % by weight ethylene glycol monobutyl ether which is also known as butoxy ethanol or by its common name of butyl Cellosolve Sodium metasilicate is severly irritating to the eyes skin and mucus membranes Ethylene glycol monobutyl ether or butoxy ethanol The current OSHA standard is absorbed by the skin for butoxy ethanol is and is a 50 ppm hemolytic agent The 1981 Threshold Limit Value TLV listed in the American Conference of Govermental Industrial Hygienist ACGIH booklet reduced the TLV to 25 ppm Wearing of goggles or D MAINTENANCE GARAGE 202 x 64 i 2 3 4 5 6 7 oa a oa me ws a Fr rT N co No Books ; Body bop Teak General Shop Area 84 x 111 14 Work Bays | Bay Palat Aces Shop on L 14 13 12 11 10 8 8 U. S. POST OFFICE NASHVILLE TENNESSEE October 1986 Figure 1. Floor Plan of USPS Carage and Shops o. COVER COVER COVER nani. o , 7 ~~ a _ \ Tue ce 16 HANDLE ~ 16:03 SWITCH BRUSH RINSE HOSE 201 / ^' VALVE CORD POWER . WORK SHELF PUMP CATCH BASIN ~ RIGID CASTERS PUMP INTAKE SCREE SWIVEL CASTERS BARRIER FILTER FILTER WORK SHELF 2 Brake Washer Assembly Unit Figure eek 16,18 16,18 13 200 P. 13 side shield recommended safety glasses for preventing and rubber or chemical resistant clothing is skin contact when handling Greasoff /No. 19 The washer unit has a gallon capacity During our survey this facility disposed of the used liquid on were performed each month with a monthly basis the liquid being Approximately 25 brake jobs changed after each 10 to 12 brake jobs The ten gallons of used brake cleaner is placed in sealed gallon cans and marked in accordance with EPA instructions for An approved contractor picks up the used liquid and disposes of disposal it in an approved toxic waste site Some of the features of the brake washer assembly include 1 A gentle flow of solvent to the workshelf basin area to wel the back plate and brake components in order to avoid spreading dust into the air and at the same time clean the components spillage 2 A low center of gravity to avoid tipping and may contain asbestos fibers of solution which 3 An adjustable work tray allowing the mechanic to position the tray at a height to avoid splashing and spillage 14 design that can Can maintain safe be used on both automobiles and work practices for all types of trucks so vehicles the mechanic -- 5 A reservoir equipped with a removable cover to prevent liquid evaporation when covered and as a work tray when the cover is removed for work on large vehicles The manufacturer recommends the following sequence for use of their unit for brake shoe servicing 1 Fill the reservoir with one gallon of brake cleaner concentrate and five gallons of water 2 Make sure the switch is in OFF position and plug into power source 3 Make cure the bruch is positioned toward the solvent supply or in the catch basin to prevent accidental spillage and loss of solution Do not leave brush and hose assembly on the floor 4 If the vehicle is on a lift place the machine so that the catch basin is directly under the brake assembly Height of the catch basin can be adjusted for convenience of the mechanic If the vehicle is raised by a front lift or jack as is often the case with trucks cleaning can be done by removing the catch basin opening the hinged cover of the main reservoir tank and cleaning over the expanded metal mesh covering the fluid reservoir 10 jct 16 16:00:13 16:00:116:030:13 2011 P. 5 Turn the switch ON and the fluid will be pumped through the brush hose assembly and cleaning can commence Regulation of the fluid flow is controlled by a valve at the pump connection 6 The Thru brush provides a wetting action to wash away dust asbestos fibers oil and grease Small parts can be conveniently cleaned and stored in the catch basin or in the main tank 7 Fluid should be disposed of in accordance with local state and federal requirements The barrier filter should be washed at this time The mechanics worked confidently with this brake washer believed it did a good job of containing and collecting employed on any size vehicle assembly unit and brake dust when III METHODOLOGY Air Sampling and Analysis Personal air samples for asbestos were collected in duplicate on 0.8 pore size 25 diameter cellulose ester membrane filters at 3.0 1pm for the duration of a single brake job or 2 hours whichever was longer The total volume collected 360 liters allowed a limit of detection of approximately 0.004 fibers by Phase Contrast Microscopy PCM analysis Area air samples for asbestos were collected on cellulose ester filters Two area samples were collected at the vehicle fender and the axle source samples at approximately 7.0 1pm for the duration of a single brake job or 2 hours whichever was longer The source samples were used to measure fibers escaping into the working environment during activity The minimum volume collected 840 the cleansing and liters allowed a repair limit of detection of 0.002 fibers by PCM Two additional area samples were collected in the general garage area background at approximately 7.0 1pm for a hour period encompassing pre- and brake job activities These background samples were used to determine effects of general shop cleanliness and overall containment effectiveness of the controls The minimum volume collected 1,680 liters allowed a limit of detection of 0.001 fibers Two other area samples were collected out of doors several hundred feet from the Imsilding Imsilding - 30 1 from from Apptimate Apptimate Apptimate lam pecial pecial pecial These These samples were used to determine environmental levels of asbestos The minimum volume collected 1,440 liters allowed a limit of detection of 0.001 fibers All filter air samples were analyzed by Phase Contrast Microscopy PCM in accordance with NIOSH Method 7400. In addition to PCM analysis approximately 2/3 of these samples were analyzed by field Transmission Electron samples Microscopy the direct TEM To facilitate analysis by PCM transfer method of sample preparation and TEM on the same described by Burdett and Rood was used For PCM analysis all fibers with a 1 or greater ratio were counted using Method 7400B counting rules TEM analysis of these samples show that more than 85 of the chrysotile fibers counted using the A rules would also have been counted using the B rules For TEM analysis 11  - eet 16 16:00:14 2001 15 fiber type and size distribution were obtained for all fibers greater than approximately 0.25 um diameter using a magnification of 17,600X and counting either a minimum of 10 grids or 100 particles whichever came first Bulk Samples and Rafter Sample Field blanks were prepared for each sampling date TEM analysis Twelve blanks were analyzed by PCM these results are shown in Table 1 of Appendix A. show all blanks were below detectable limits and submitted for PCM and and 6 blanks Analycic by by TEM and PCM and TEM , A bulk brake dust samples for each vehicle and a bulk rafter sample for the site were collected and analyzed for asbestos by TEM The percentage of asbestos in the bulk samples was qualitatively determined by estimating the ratio of the number of asbestos fibers to total dust particles The percentage of fibers that were asbestos was quantitatively determined the length and diameter of asbestos and other fibers were measured Elemental analysis of the nonasbestiform constituents was performed using energy dispersive ray analysis Time Monitoring The entire brake maintenance operation was recorded on videotape Two Hand Aerosol Monitors HAMS ppm Inc. Knoxville Tennessee and a personal computer Apple II Plus were used to measure and record the dust levels The HAM's optical system provides instantaneous measurements of total dust levels in mat one second intervals The HAM sends a millivolt signal to the computer which records it as a relative dust level The computer program can record a maximum of 2,000 readings at a minimum of four second intervals before it has to be reset The HAMS measured the dust levels in the operator's breathing zone and in the area beneath the vehicle's axle Before each brake maintenance job the HAMS were calibrated and zeroed The DuPont P4000 computer's clock was or MSA Model G pumps synchronized with were connected by that of the video camera tubing to each HAM and each HAM in turn was connected by a foot electrical lead to the computer programmed to receive and the other HAM was the set data The brake beneath the axle maintenance operator wore of the vehicle undergoing one HAM brake maintenance The computer recorded these dust levels on a disk from which a plot was later made By comparing the plot to the video recording of that brake maintenance operation dust sources due to work practices and enclosure leaks could be identified Although the HAMS are not specific for asbestos if the asbestos fibers are brake dust which seems to dispersed along with the other components of the be a resonable assumption then the HAM should be a useful real time indicator for control of asbestos laden dust Using a spreadsheet program Lotus 1-2-3 a time plot of the dust was made By comparing the peaks from this plot with the video work practices producing elevated dust levels can be identified levels Ventilation Kurz Model No. 480 and TSI Model No. 1630 air velocity meters were used to 12 DIE eet 16 36:00:136:200:12 2001 F. TG measure air velocities to garage Smoke tubes were patterns determine flow used to assist rates and wind in observation directions of general in the airflow Air temperature humidity and wind conditions were determined using an aspirated psychrometer and velocity meters Ergonomic Evaluation of Brake Maintenance and Repair An ergonomic evaluation was conducted on workers performing brake maintenance and repair to determine work practices which may cause personal asbestos dust exposure while during routine using brake a brake washer inspection and assembly unit Each worker was videotaped brake replacement tasks Work cycle times and work analysis were performed from videotapes in the laboratory Cycle times were taken while running the video tapes at normal speed while work analysis was conducted at both normal speed and by action techniques Work analysis included breaking the job into general tasks which could be matched with airborne dust levels during brake Work tasks which could cause personal exposure inspectiaonnd replacement to brake dust were identified Interviews were conducted with eight vehicle maintenance workers who do brake work Data were collected on a standardized questionnaire see Appendix B and analyzed Basic descriptive demographic and work history data were gathered from each worker Information from these interviews were compared to workplace observations by the NIOSH research team IV RESULTS Time Sampling Results Real total total dust data were collected using Held Aerosol Monitors HAM's connected to an Apple II Plus computer Two time samples were collected one alongside the personal sample on the brake mechanic and the other just below the vehicle's axle time data collection was during actual brake maintenance operations approximately an hour in duration and was obtained during all 10 brake maintenance jobs Nine different operators performed the brake maintenance jobs on these 10 vehicles The general brake maintenance procedure was - Remove the wheel's lug bolts and the wheel average time 17 seconds - Remove the brake drum average time 17 seconds Thirty percent of the operators let drum and the support the cleansing liquid run down between the brake plate for about 15 seconds before removing the drum - Thoroughly wash the drum brake shoes and brake support plate for about 80 seconds - Inspect the brake shoes If they do not need replacing reinstall the brake drum wheel and lug bolts average time 60 seconds 13 To get 16 16:00:13 16:00:13 16:00:13 2001 17 . C - For brake shoes that are to be replaced remove the brake shoes average time 100 seconds would wash the support plate For and 30 of the replacements related gear for another the operator 10 to 40 seconds - Install the new brake shoes average time 280 seconds - Reinstall the brake drum average time 10 seconds - Remount the wheel and tighten the lug bolts average time 60 seconds To interpret the time computer data the instruments background level 0.05 millivolts is used as the reference point at this facility This background level is the Apple's internal noise level and values below it are considered to be unreliable as to accuracy and were not used Values above this reference level are used to identify the dust sources By determining the magnitudes value above the reference point with time these dust exposures relative dust exposures due to certain phases of of the brake job can be identified and compared Real data detected brief elevations of total dust during the removal of the The lug bolts and the drum and greatest potential asbegr.ng during the reinstallation of the lug bolts our exposure occurs during removal of the Clube J. _ __ Cobb eed Lee Che 2 111 111 111 111__1 D -5 to contain asbestos fibers For 38 of the drums removed dust levels were up to nine expoced times that of the reference level to olovated duct lovolc from It For each brake job the to 11.0 avoraging 3.6 worker of the With total time spent in removing the brake drums The second highest dust levels detected were during the removal of the lug bollo from the whoelo Thooo lovold woro up to throo timos tho referenco level on 18 of the brake jobc When roinstalling the wheel and tightening the lug bolts dust levels were up to 1.5 times above the reference level in 10 of the operations dust levels 0.2 % of the For each brake job total time spent in the worker was exposed to elevated loosening and lightening of the lug bolts Removing the old and installing the new brake shoes resulted in alightly elevated dust levels up to 1 times above the reference level in % of the brakes replaced For each brake jub the wucher was expused to elevated dust levels from 0.2 to 0.3 of the total time spent in removing and instulling of the brake shoes On the third brake maintenance operation there exposures during the time it took to remove the dust levels were seven to right times above the were prolonged elevated dust lugs from two wheels The reforemen level and averaged 5.1 of the total brake maintenance time for two wheels on one vehicle When the impact wrench dropped indicating a was replaced dust levels faulty impact wrench and exposure time both Also noted was the cleanliness of the rams. of the full whatls 20 could wheels the amount of road be demerited as clean 60 dust on the Fair and 20 14 ia ve 16_16 16_16 13 2001 P. 18 dirty From the time data there was no clear relationship between dust exposures and cleanliness of the wheel The greatest potential to asbestos exposure drum This potential appears to be reduced is during the removal of the when the cleansing liquid is brake allowed to flow between the brake drum and brakte support plate before the drum is removed The nign oust level experienced ouring the removal and rightening of the lug bolts appears to be due more to the impact wrench than the road dust on the rim One faulty or worn out impact wrench significantly increased the total dust levels when it was used on two of the forty wheels as noted previously by directing compressed air onto the wheel being serviced The elevated time dust readings may also have been from an oil mist aerosol from the wrench generated by the compressed air Thorough washing of the brake support plate brake shoes and gear used to attach the brake shoes appeared to remove or wet most of the asbestos dust before the operator started to manually remove the old shoe and install the NW 91 SMAL All All All LALA da of brake shoe replacements a laval weet Towle Towle Towle Towle Towle duine duine Air Sampling Results Individual fillum samplo moulto fom olmboomo Table A of Appendix A and are summarized in o /bo0400Siboro Tables 1 and 2. Owe presented in The results for samples analyzed by Phase Contrast Microscopy PCM are presented in Table 1 Personal asbestos sample concentrations for the brake mechanics averaged less than the detection limit of 0.004 fibers with only one sample above 0.004 fibers Source samples taken above the wheel fender averaged less than 0.002 fibers source samples hung over the axle and centered between the wheals averaged less than 0.002 fibers background samples collected at two separate locations in the garage averaged less than 0.001 fibers and outdoor ambient samples averaged less than 0.001 fibers As stated earlier TEM analysis of these samples show that more than 85 of the chrysotile fibers counted using the A rules would also have been counted using the B rules Nineteen of the dotection limit 20 personal samples of 0.004 fibers Laken during 10 brake jobs were below the Because personal sample concentrations represented exposures while servicing brakes and this usually takes no more than 2 to 3 hours per shift would be even lower than the the mechanics weighted measured levels averages exposure Only 1 of the 76 samples analyzed by PCM was above the detectable limit thus analyses comparing brake mechanics type of vehicle and differences between brake inspection and brake replacements were not done Transmission Electron Microscopy TEM results are summarized in Table 2. fibers identified as chrysotile or amphibole asbestos with an aspect ratio 1 or greater were counted fibers 0.25 microns and longer are included few samples contained fibers that were not identified no I.D. but could possibly be asbestos All of A 15 16 16:00:13 16:0:13 16:00:13 2001 Table 1 Phase Contrast Microscopy Concentrations for 10 Vehicles fibers Sample Type Number of Samples Arithmetic Mean Range Personal Fender Axle Background Ambient 20 0.004 0.004 - 0.006 10 0.002 0.002 0.002 10 0.002 0.002 16 0.001 0.001 0.001 8 0.001 0.001 0.001 Table 2 TEM Concentrations for 10 Vehicle fihers Brake Jobs Sample Type Number of Samples Arithmetic Mean Standard Deviation . Range Personal Fender Axle Background | Ambient 10 10 10 8 4 0.008 0.009 0.004 0.002 0.002 0.003 0.012 0.004 0.001 0.001 0.006 - 0.013 0.002 - 0.040 0.002 - 0.016 0.001 - 0.006 0.002 - 0.003 16 THE OCE 16 J6 00 13 2001 P. 20 The arithmetic mean TEM concentration Table 2 for all personal samples was 0.008 fibers with a standard deviation of 0.003 fibers This concentration was higher than the background levels in the building which averaged 0.002 fibers and the outdoor ambient levels which averaged 0.002 fibers Source samples taken at the axle averaged 0.004 fibers while samples taken at the fender above the wheel averaged 0.009 Pibers The TEM source sample results were only slightly above background levels Because most concentrations were below detectable limits and detectable concentrations were not much above detectable limits tests of significance were not performed on this data Asbestos fibers chrysotile or amphibole greater than or equal to 5 um in length were found in only 12 of the 48 samples analyzed by TEM Two personal samples showed fibers greater than 5 um Asbestos fibers that were in a matrix partially hidden by particles fibers and X fibers - fibers that extended into another field - are not included in Table 2 but are denoted in Appendix A. Four of 48 samples analyzed by TEM contained M or X asbestos fibers and one of these samples would show substantially higher concentrations had M or X fibers been included Bulk and Rafter Sample Results Bulk samples were collected from the drums of nine of the vehicles tested In addition a rafter sample was collected and analyzed The bulk sample results are presented in Table 3. Less than % of the of the bulk samples and the rafter sample were constituted virtually all the fibers that were total material dust in each asbestos although asbestos found From 83 to 100 of the fibers in the 9 brake drum bulk samples were chrysotile with two of the nine samples containing 100 chrysotile asbestos fibers Two of the brake drum bulk samples contained amphibole fibers From 0 to % of asbestos fibers and bundles were longer than 5 microns Three percent of the fibers from brake job No. 1 bulk sample were larger than 5 um The remaining eight bulk samples contained % or fewer chrysotile fibers longer than 5 microns The rafter sample contained 99 chrysotile fibers with % of the asbestos fibers larger than 5 microns The OSHA Standard or 0.2 fibers Action level 0.1 fibers cc and the NIOSH recommended exposure limit of 0.1 fibers for asbestos 8 hour time weighted average are based on PCM analysis of asbestos using A counting rules B counting rules were utilized in this research study As noted earlier TEM analysis of these samples show that more than 85 of the chrysotile fibers counted using the A rules would also have been counted using the B rules Based on the levels measured by both PCM and TEM however the mechanic's expocure in this study would be well below these recommended levels V. CONTROL TECHNOLOGY Occupational exposures can be controlled by the application of a number of known principles including engineering measures ventilation isolation and substitution work practices and personal protection Ongoing monitoring and maintenance of controls to insure proper use and operating conditions and the education and commitment of both workers and management to occupational health are also important ingredients of a complete effective and durable control system These principles of control apply to all 17 The Nigh 16 18501 13 2001 D D Brake Job Vehicle 6 Year Sample No. 1 Jeep 1976 2 2 1977 3 - 3 1977 4 - 4 1978 5 - , ,, , 1977 6 6 1978 7 7 1981 8 " by 1973 Y . 10 1974 10 Rafter 1 Table 3 Bulk Sample Results Grids Examined Amphibole Number of Chrysotile and Amphibole Fibers I of Total Fibers Chrysorile and Amphibole Chrysotile and Amphibole Fibers 15 up 9 No 83 83 3 4 No 97 88 0 3 1 116 96 0 10 No ' 97 0 4 2 115 97 0 4 2 112 1 10 H 41 100 0 10 No 54 100 0 10 No 8 No 19 100 86 99 7 * Includes fibers fibers in a matrix and bundles 18 The Och 16 16:00:13 2001 P. 22 situations but their optimum application varies from case to case application of these principles are discussed below The Engineering controls The all brake brake washer lining assembly unit is used at this garagteo contain and collect dust including potentially hazardous asbestos fiber content The unit which is fully described in Section II is used during all brake inspection repair and brake lining replacement In this study the entire brake service job was monitored including all four wheels The results discussed below represent fiber PCM and asbestos TEM concentrations during the entire brake job consisting of all four wheels The effectiveness of the brake washer assembly is evidenced by the very low exposures for the brake mechanics Nineteen of the 20 personal samples analyzed by PCM were below the detectable limits below the current OSHA standard of 0.2 fibers of 0.004 fibers well and the NIOSH recommended standard of 0.1 fibers Low fiber concentrations by PCM were also found for the source sample placed on the fender directly above the wheel After completing servicing to the first wheel this sample was moved to the fender above the other wheels so that this sample included dust emissions from all four wheels The fender sample concentration for each of the was less than 0.002 fibers The other source sample hung showed concentrations of less than 0.002 fibers for all 10 10 brake jobs over the axle brake jobs The importance of this source sample is that it propelled by the brake washer assembly unit shows dust fibers liquid toward the were not being other side of the vehicle As noted earlier TEM analysis of than 85 of the chrysotile fibers counted using these samples the A rules show that more would also have been counted using the B rules TEM results were also used to evaluate the effectiveness of the brake washer assembly unit The TEM results are not directly comparable to the PCM data because TEM includes all size fibers whereas PCM includes only fibers longer than 5 um and with a diameter greater than about 0.3 um and TEM includes only fibers identified as asbestos whereas PCM includes all fibers larger than 5 um The TEM personal sample results Table 2 show asbestos fibers were controlled to very low levels with use of the brake washer assembly The personal sample arithmetic mean concentration and geometric mean concentrations jobs were , 0.003 and 0.009 fibers respectively for all 10 ; brake Fender sample asbestos concentrations were very low ranging from detectable limit of 0.004 to a high of 0.040 Fibers The axle samples were also very low ranging from 0.004 to a high of 0.016 the source fibers Background and ambient asbestos concentrations by TEM averaged 0.002 fibers These low asbestos levels indicate that the asbestos in the personal not from and source samples outdoor sources or was from activities such from resuspended dust in as brake servicing the garage and The sampling at the Nashville Postal Service weather October with some doors open most garage of the was conducted in mild time Natural ventilation 19 The OrOr 16 16:00:13 16:00:116:030:13 2004 23 Table 4 Work Task Analysis of Brake Inspection and Replacement Step Work Task Brake Dust Exposure Sources 1 Use pneumatic wrench to remove fivo lugo from whool Loose rim dust around lugs and tire 2 Remove wheel from vehicle 3 Remove brake drum and sets on floor Loose dust from drum and brake components may become airborne 4 Worker positions brake assembly washer unit under brake assembly 5 Worker uses wet brush stylus to clean brake components 6 Worker removes brake components and When brake components are not cleans each piece throughly washed in step 5 7 Worker cleans axle surface loose dust from components during removal and installation in steps 6 and 8 8 Worker assembles brake components and installs new brake shoes 0 Brake drum is wet washed with brake washer assembly unit wiped put back on brake unit clean and 10 Wheel is put back on vehicle 11 wheel luge are pneumatically tightened wheel Loose rim dust around luge and tire 20 hue eet 16 16:00:13 16:00:13 16:00:13 2001 P. 24 due to the open doors may have helped to minimize levels although there was no measurable increase background levels when some doors were closed the airborne asbestos in the personal source -- -- Work Practice Results Table 4 shows the work task analysis of a brake inspection and replacement job while using the brake washer assembly unit Potential asbestos exposur^ points while performing this task are also noted The average work cycle time for a wheel brake inspection task was 12 minutes As seen from Table 4 asbestos exposure during brake maintenance and repair may occur during the initial tasks of removing the wheel and brake drum from the vehicle Good work practices observed by some of the workers to reduce these exposure points are the use of a wet brush on the wheel and on the back of the brake drum and assembly to suppress dust before removing the brake drum Bad work practices included using a dry rag to wipe down the brake drum and assembly as a substitute for the wet wash unit the use of a hammer to loosen frozen brake drums without first suppressing dust with wet control methods and taking soiled clothing home to wash Demographic and work practices were obtained from interviews of eight workers All eight workers were male ranged in age from 19 to 54 years and the average age was 38.2 - 12.8 years As a group these men had 4.0 + 1.9 years experience as mechanics and performed 5.6 - 2.5 brake jobs per week The other job duties included general maintenance engine tune repair work and use of hydraulic equipment Seven of the workers indicated their right hand was dominant in performing work while one claimed to be ambidextrous Tools and equipment commonly used during brake maintenance and repair included brake spring remover pliers hammer brake washer unit solvent dust mask and impact wrench brake adjustment tool brake shoe Five of eight employees indicated toul power air tool they were provided with training with regard to asbestos exposure during brake maintenance the training lasted anywhere from one to eight hours and usually took place when employees started working with the U.S. Postal Service Workers remembered from their training precautions and not the use of a respirator to use compressed air to clean blow out procedures and safety brake dust All eight workers indicated they had a physical examination before being hired by the Postal Service and all but one employee indicated having a physical exam within the past year one employee indicated a physical exam in March 1985 Three of eight workers reported having an ray as part of their physical examination Analysis of workers with and without rays showed an age dependent pattern with all three workers who age When asked if the workers did anything had rays special to being over 40 years of protect themselves for brake dust all indicated use of a dust respirator and use of the brake washer assembly unit Personal protective equipment worn by all workers included work clothing and a respirator gloves and other items such as safety glasses and safety shoes were not indicated Shower facilities were available for all workers however only three indicated regular use before leaving work Two trainee workers reported they did not change out of their work clothes before Po t 21 Lun oer 16 16:10:116:010:10 2001 25 leaving service work The U. S. Postal Service for the regular work force provides work clothes and laundry In summary this information revealed that these workers were aware of the hazards of asbestos exposure while working on brakes In addition they generally used control devices such as disposable quarter mask respirators nuisance dust and the brake maintenance and repair washer assembly unit when performing brake for VI CONCLUSIONS AND RECOMMENDATIONS The for use the of this brake washer assembly resulted in very low asbestos exposures vehicles tested indicating effective control of the asbestos dust Although it was not possible to evaluate an uncontrolled situation to determine an efficiency for the controls other work has shown peak exposures using NIOSH Analytical Methods CAM 239 of around 1 fiber and time weighted average expocure of around 0.2 fiberc with dry bruching or compressed air blowing substantially effective This data suggest that in controlling asbestos the present dust during technique was brake servicing Fender and axle source sample results showed no major differences among the vehicles tested There was almost no difference in asbestos exposures between brake inspections and brake replacements based on TEM results TEM results were of much greater value than PCM results for evaluating the brake assembly washer since the asbestos levels were quite low The primary use of the PCM data was to demonstrate that exposures were well below the OSHA standard and NIOSH recommended level since both the standard and recommended level are based on the PCM procedure As noted earlier TEM analysis of these samples show that more than 85 of rules would also have been counted the chrysotile fibers using the B rules counted using the A Since the TEM method is more sensitive and background and this allowed comparison between personal or source ambient levels all of which were quite low samples Bulk sample results analyzed by TEM show that the brakes of the vehicles tested in this study contained chrysotile asbestos fibers and therefore had asbestos brakes Fibers found in the drums of the nine vehicles tested were between 83 and 100 chrysotile with 2 vehicles having 100 chrysotile fibers Less than % of the total material dust in each of the bulk samples and the rafter sample were asbestos although asbestos constituted virtually all the fibers that were found An analysis of the video and time total dust data indicates that some dust emission peaks may be reduced by altering work practices such as 1 allowing the plate before cleansing fluid to flow between the brake drum and brake support the drum is removed and 2 after removing the brake drum throughly wetting the wheel hub and the back of the brake assembly to suppress dust and then thoroughly washing the brake support plate brake shoes and brake components used to attach the brake shoes before the operator starts to manually remove the old shoes anonh 22 biped 16 16:00:13 16:00:13 16:00:13 2001 28 Training in the developing good exposure operation and maintenance of this work practices which could reduce unit is important for potential brake asbestos Mild weather with levels than might closed some of the doors occur during cold open may have resulted weather when the doors in lower ambient are normally kept Since asbestos was identified in most brake dust samples showers are recommended a as good practice before going home from work to remove any residual dust from the body and a laundry service should be provided for cleaning soiled work clothing Further education about personal hygiene i.e. showers at work and changing soiled work clothing before leaving work may provide additional protection by not bringing asbestos dust to the home environment Maintenance and regular changing of the brake washer assembly solution is encouraged for maximum efficiency of this unit see manufacturer's recommendations VII REFERENCES 1. Dubrow Robert and David Wegman 1983. Setting Priorities for Occupational Cancer Research and Control Synthesis of the Results of Occupational Disease Surveillance Studies Journal of the National Cancer Institute 71 1142 2 Roberts Dennis R. and Zumwalde Ralph D. 1982. Asbestos Exposure Assessment for Brake Mechanics Industrial Hygiene Summary Report No. 32.4 NIOSH November 1982 3 Current Intelligence Bulletin 5 Asbestos Exposure During the Servicing of Motor Vehicle Brake and Clutch Assemblies National Institute for Occupational Safety and Health August 8 1975 A. Newhouse M.L. and H. Thompson Mesothelioma of Pleura and Peritoneum Following Exposure to Asbestos in the London Area Brit J. Ind Med 261-269 1965 5 McDonald A.D. et al Epidemiology of Primary Malignant Mesothelial Tumors in Canada Cancer 914-19 1970 6 Greenberg M. and T.A. Lloyd Davies Mesothelioma Register 1967-1968 Brit J. Ind Med 91-10A 1974 1 Lorimer W.V. A.N. Rohl A. Miller W.J. Nicholson and I.J. Selikoff Asbestos Exposure in Brake Repair Workers in the United States Mt. Sinai J. of Med 207-218 June 1976 23 The CT 16 16:00:13 16:0:13 2001 P. 27 Bader M.E. R.A. Bader A.S. Teirstein A. Miller and I.J. Selikoff Pulmonary Function and Radiographic Changes in 598 Workers with Varying Duration of Exposure to Asbestos Mt. Sinai J. of Med 492-500 1970 Davis J.M.S. and S.W. Coniam Experimental Studies on the Effects of Heated Chrysotile Asbestos and Automobile brake Lining Dust Injected into the Body Cavities of Mice Experimental and Molecular Pathology Vol 19 pp 339-353 1973 10 Koshi K. H. Hayashi and H. Sakabe Studies on Serpentine Minerals in Heat Vol 7 pp 66-85 1969 Biological and Treated State Mineralogical Ind Health , 11 Pott F. F. Huth and H. Friedricks Tumorigenic Dusts in Experimental Animals Environmental Health Vol 9 pp 313-315 1974 Effects of Fibrous Perspectives Pott F. F. Huth and K.H. Friedricks Tumorigenic Effects of Fibrous Experiments Concerning the Carcinogenic Effects of Fibrous Dusts Interpretation of Results Considering the Carcinogenesis in Humans Annales d'Anatomie Pathologique Paris 1976 Vol 21 pp 237-246 13. Davis J.M.G. The Fibrogenic Effects of Mineral Dusts Injected into Pleural Cavity of Mice British Journal Exp Pathology Vol 53 pp 190-201 1972 the Stanton M.F. M. Layard A. Tegeris The Carcinogenicity of Fibrous Glass Relation to Fiber Dimension J. Natl 1977 E. Miller M. May and E. Kent Pleural Response in the Rat in Cancer Institute 587-603 March . 15 NIOSH 1976 Revised Recommended of Health Education and Welfare p 93 December 1976 Asbestos Standard U.S. DHEW NIOSH Publication Department No. 77-169 16 NIOSH 1984 Statement of the National Institute for Occupational Safety and Health the Public Hearing on Occupational Exposure to _ Asbestos June 21 1984. Testimony on Proposed Rule Making at OSHA Hearings NIOSH Method Edition Vol 7400. 1984 NIOSH Manual 2 DHHS NIOSH Publication of Analytical No. 84-100 Methods Third Burdett Garry J. and Anthony P. Rood 1983 Membrane Transfer technique for the Analysis of Asbestos Fibers or Other Inorganic Particles by Transmission Electron Microscopy American Chemical Society Environmental Science and technology 643-649 24 The oct 18 APPONDOK A 16:012 16:00:12 Tatly A 201 Staple N aber Bate Job Vesicle- No. Year Brane Replace Scople 05 Type Inspect PCK eee Simple = Fibers Volune File Fileri Asbestos Fibers / Filter TL Asbestos Asbestos Fibers cc Astzetos * OT X Fiters 15964 10-31-86 10-31-86 1 1976 Pers i 15960 10-27-36 10-27-36 L 1975 Pers I 169 16961 10-37-86 10-37-86 L 1976 Fend ,, 3t7 150 1500 9.0041 2,377 0.406 , 360 1501 +.0042 +.0042 - ' 4.1 1 tele 4.01 19,012 0.021 16959 20-17-86 l 1976 ble 1 6180 150 1500 1.0013 2,377 0.102 0.102 a 11955 10-17-86 . 1975 Ickg I 162 1 ... 0.09 0.009 4.753 0.713 : P. 15962 10-17-86 { 1976 BC I 1703 150 1500 1.0009 9,506 9,506 0.266 0.266 10963 10-17-86 1 1976 ... 1 14.3 14.3 1500 4.01 4.0011 2,377 0.002 0.002 15956 10-17-86 L 16953 10-37-86 z 1976 And I 1977 R Laid 301 130 130 0.01 0.0011 1503 1503 4.0041 ~ 2,377 : 0.006 76951 10-17-86 z 1977 Pirg a 360 1560 0.0092 - : 76954 10-27-86 10-27-86 ^' 1977 Pend K 9.1 1500 1.0.16 1.0.16 23,519 0.8 - 16957 10-27-86 1977 Ale & 7.250 10-110-177-86 -108-176-86 i 1977 Brig R 16249 10-27-86 fy 1977 Ickg 3 76247 10-28-86 10-28-86 3 1977 ---- -- 1160 1500 8.0113 8.0113 2,377 0. 02 1932 1 Sene 1.0109 1.0109 - ; 1763 1500 0.009 0.0009 - . 160 15 * .0042 33,272 0.792 ws) 15242 10-28-86 j 1977 Pers 7 76241 00 10-16-86 } 0977 Fend 8 73248 10-28-86 3 1977 Ale 3 76246 10-29-86 3 1977 BC48 R 16245 10-28-810-268-86 3 1977 Ickg R 76243 10-28-86 10-28-86 3 1977 AD 3 R 76244 10-25-810-265-86 3 1977 5 Q 20000 = 10-28-86 10-28-86 10-28-86 a 1978 Pers 1 16999 10-25-810-265-86 4 1978 Pers C 238 10-23-810-263-86 & 1978 Fend t 367 1500 0.0041 - ' 11x0 1560 4.0113 2,377 0.702 J 11 1500 1.016 1.0016 14,259 0.016 0.016 : 1702 150 1500 0.0009 0.0009 2,377 OAL 168 1500 ( .0009 4,753 0.103 1469 1500 1.0010 4,753 0.00 C 1440 1500 .0 - . 107 +367 156 156 1.0641 1500 0.0041 2,377 - 0.007 : OLL 1300 1.0016 2,377 0.003 continued "/ . 16 18:13 APPENDIX A 18:13 18:13 Table A 201 Sample Number Date Joh Vehiclel No. Year Brake Replace Sample or Type Inspect Sample Volume Fibers Filter Fibers wee ee ee Asbestos TEM Fibers / Filter Asbestos Fibers Asbestog2 Mor X Fibers 25964 10-27-80 1 1976 Pers I 25960 10-27-86 L 1976 Pers I 307 1500 0.0041 0.0041 2,377 0.006 DIO O40150COIO 360 1500 0.0042 DIO O O 401 510 CO IOIO 25961 10-27-86 L 1976 Fend I 911 1500 0.0016 0.0016 19,012 0.021 25959 10-27-86 1 1976 Axle I 1160 1500 0.0013 2,377 0.002 0.002 25955 10-27-86 I 1976 Bckz I 1702 1500 0.0009 0.0009 4,753 0.003 0.003 P. 25962 10-27-86 I 1976 Bckg 1 1718 1500 0.0009 0.0009 9,506 9,506 0.006 25963 10-27-86 1 1976 Amb 1 34133413 1500 0.0 1 0.0011 2,377 0.002 0.002 25956 27-86 i 1976 Amb I 1413 1500 0.0011 DIO4015C 25953 10-27-86 2 1977 Pers R 25951 10-27-86 2 1977 Pers R 307 1500 0.0041 0.0041 360 1500 0.0042 2,377 0.006 0.006 25954 10-27-86 2 1977 Fend K 911 1500 0.0016 0.0016 28,519 0.031 25 25957 10-27-86 2 1977 Axle R 25250 10-27-86 10-27-86 2 1977 Bckg R 1160 1500 0.0013 1732 1500 0.0009 0.0009 2,377 0.002 0.002 25249 10-27-86 2 1977 Bckg R 1763 1500 0.0009 25247 = 10-28-86 3 1977 Pers -- 380 1500 0.0042 0.0042 33,272 0.092 25242 10-28-86 3 1977 Pers R 367 1500 0.0041 25241 10-28-86 3 1977 Fend R 1160 1500 0.0013 2,377 0.002 25248 10-28-86 3 1977 Axle R 25246 10-28-86 3 1977 Bckg R 911 1500 0.0016 1702 1500 0.0009 0.0009 14,259 2,377 0.016 0.016 0.001 25245 10-28-86 3 1977 Bckg R 25243 10-28-86 3 1977 Amb R 25244 10-28-86 3 1977 Amb 8 251000 10-28-86 4 1978 Pers 1 25999 10-28-86 4 1978 Pers I 25238 10-28-86 4 1978 Fend I 1680 1500 0.0009 0.0009 4,753 0.003 0.003 DIO4015C 1469 1440 367 367 911 1500 1500 1500 1500 1500 ' 4,753 0.0010 0.0010 0.0041 0.0041 2,377 0.0016 2,377 0.003 0.007 0.003 | continued continued The Oct 16 16:00:13 APPENDIX A 16:03 Cable A continued 201 Sample Number Date Job Vehiclel No. Year Sample Type Brake Replace R or Inspect [ Sample Volume a PCM Fibers Fliter Fibers Asbestos Asbestos Fibers Fibers Filter Filter Asbestos Fibers Asbestoa or X Fibets 2588 10-28-86 4 1978 Axle I 1160 1.500 0.0013 2,377 0.002 OI O O O O 25237 10-28-86 10-28-86 4 1978 Bckg I 1958 1500 0.0008 2556 10-28-86 4 1978 Bckg I 2554 10-29-86 3 1977 Pers R 25988 10-29-86 5 1977 Pers R 25993 10-29-86 5 1977 Fend R 25994 10-29-86 5 1977 Axle R 25992 10-29-86 5 1977 Bckg -- 25985 10-29-86 5 1977 Bckg R 25991 10-29-86 5 1977 Amb K 1950 1500 0.0008 0.0008 305 1500 0.0041 2,377 0.007 OI O O O O 360 1500 0.0042 0.0042 911 1500 0.0016 4,753 0.005 OI O O O O 1160 1500 0.0013 2,377 0.002 0.002 OI O O O O 1807 1500 0.0006 0.0006 2,377 0.001 OI O O O 1800 1500 0.0006 0.0006 2,377 0.001 OI O O O O 1450 1500 0.0010 2,377 0.002 OI O O O 1445 2552 10-29-86 5 1977 Amb -- 25987 10-29-86 1978 Pers I 26 6 2593 10-29-8b10-29-8b 6 1978 Pets I 2567 10-29-86 6 1978 Fend t 25986 10-29-86 10-29-86 6 1978 Axle 1500 0.0010 360 1500 0.0042 2,377 0.007 OI O O O 365 1500 0.0041 918 1500 0.0016 2,377 0.003 OI O O O O 1170 1500 0.0013 4,753 . 0.004 OI O O O 25981 10-29-86 6 1978 Bckg I 1807 1500 0.0006 0.0 0 25978 10-29-86 6 1978 Bckg I : 1800 1500 0.0000 = 25970 10-29-86 7 1981 Pera R 365 1500 0.0041 2,377 0.007 OI O O O 25969 10-29-86 7 1981 Pets R 25975 10-29-86 7 1981 Fend R 25976 10-29-86 7 1981 Axle R 25966 10-30-86 8 1976 Pers R 360 1500 0.0042 1160 1500 0.0013 2,377 0.002 OI O O O O 1160 1160 1500 0.0 13 0.0013 2,377 0.002 OI O O O O 356 2000 0.0056 0.0056 2,377 0.007 OI O O O O 25965 10-30-86 3 1976 Pera R 25967 10-30-86 8 1976 Fend R 2575 10-30-86 8 1.976 Axle R 351 1500 0.0043 0.0043 1170 1500 0.0013 2,377 0.002 OI O O O O 918 1500 0.0016 0.0016 2,377 0.003 OI O O O continued The D 6t 16 16:0:13 APPENDIX A 16:013 Table A continued continued 16:0:13 20 1 Brake PCM ; TEM S eee Replace Asbestos Sample Number Date Job Vehiclel No. Year Sample 05 Type Inspect Sample Sample Volume Fibers Filter . Fibers Fibers Filter Asbestos Fibers 1 or X Fibers 25974 10-30-86 B 1970 Bckg R 2026 1500 0.0007 0.0007 9,506 9,506 0.005 0.005 25968 10-30-86 8 1976 Bckg R 2025 1500 0.0007 0.0007 2,377 0.001 25913 10-30-80 10-30-80 8 1976 Amb H 25972 10-30-86 8 1976 Amb R 25234 10--30-86 9 1973 Pera R 25233 10-30-86 9 1973 Pers R 25232 10-30-86 10-30-86 y 1973 Fend -- 1400 1500 0.0011 2,377 0.002 COIND01 1400 377 372 11/7 1500 1500 1500 1500 0.0011 0.0040 0.0040 0.0013 - 4,753 - 47,531 - 0.013 - 0.040 0.040 25231 10-30-86 9 1973 Axle R 926 1500 0.0017 0.0017 4,753 0.005 COIONIDO01OIDOI 30 25229 10-30-86 -- 1973 Ackg R 25230 30-30-86 9 1973 Bckg xxx 25226 10-30-86 10 1974 Pers xxx 25228 10-30-810-360-86 10 1974 Perg xxx 25227 10-310-300-86 -180-306-86 10 1974 Fend R 25225 10-30-86 10 1974 Axle R 1514 1500 0.0010 - ~ COINDO01IDOI 1500 1500 0.0010 360 1500 0.0042 - 2,377 - 0.007 365 1500 0.0041 - - 1160 1500 0.0013 911 1500 0.0016 2,377 2,377 0.002 0.003 25958 10-27-86 1,2 Blank 0 1500 0 - 25952 10-27-86 1,2 Blank 1500 IOIOOOIOI - 25240 10-28-86 3,4 Blank 1500 IO OIO - 25239 2573 25979 25982 25980 25235 25236 25223 25224 10-28-86 10-29-86 10-29-86 3.4 5,6 10-29-86 5,6,7 10-29-86 > 6,7 10-29-86 5,6,7 10-30-86 8,9,10 10-30-86 8,9,10 10-30-86 8,9,10 8,9,10 10-30-86 8,9,10 Blank Blank Blank Blank Blank Blank Blank Blank Blank 1500 1500 1500 1500 1500 O 1500 1500 1500 1500 IOIOOOIOI - IO OIO - COIND01 IOIOOOIOI - IOIOOIOI - IOIOOOIOI ~ IO OIO - IOIOOOIOI - COIND01OI IOIOOIOI - IOIOOOIOI - 1 AM General DJSD Jeep M - Matrix fiber X = Fiber extended beyond grid Tub Out 16 16:00:13 16:00:161:030:13 2001 P. 32 50272-101 50272-101 50272-101 t 2 [ REPORT 1. REPORT NO DOCUMENTATION t ) ! PAGE i 4. Title and Subtitle Depth Controls Survey Report Evaluation of Brake Drum at United States Postal Service Vehicle Service Maintenance Facility Nashville Tennessee Report No. 152-20B 7. Author Godbey F. W. T. C. Cooper J. W. Sheehy D. M. O'Brien H. D. Van Wagenen J. D. McGlothlin and W. F. Todd 9. Performing Organization Name and Address , Engineering Control Technology Branch Division of Physical } Sciences and Engineering NIOSH Cincinnati Ohio 12. Sponsoring Organization Name and Address = 3 32" PB88-162193 PB88-162193 | 5. Report Date 87/08/00 6 8. Performing Organization Rept No CT 152-20B 10. Project Unit No. 11. Contract or Grant No. C G 13. Type of Report & Period Covered 14 _ a 15. Supplementary Notes i t provision 0.004f 15. Abstract Limit 200 words washer assembly unit Kleer Model LW Rollabout F The effectiveness of a brake of automotive brakes was to asbestos 1332214 during the servicing limiting exposure Post Office Maintenance Garage in Nashville TN A fleet of 575 had 13 or evaluated as the U.S. serviced at this facility Most of the vehicles Jeep delivery vehicles are and 10 inch long brake shoes Ventilation in the garage was minimal from the outside 14 inch wheels for fresh heated air During winter months there was no ventilation in in the summer they provided good When the 14 bay doors were open of concentrated detergent Greasoff No. 19 was conjunction with roof fans One gallon were recorded when used diluted to clean 40 to 50 wheels Very low asbestos exposures mechanics Personal air samples for the brake this washing assembly was in operlaitmiiotn of 0.004 fibers centimeter cc with averaged less than the detection Of the ten vehicles tested fibers found in the drums only one sample above chrysotile 12001295 with two vehicles having 100 were between 83 to 100 percent recommend showers for employees before they go percent asbestos fibers The authors y and further education home from work a laundry service to clean soiled work clothing of this particular work The authors conclude that hazards concerning the potential of this brake washer assembly resulted in very low asbestos exposures use 17. Document Analysis 8. Descriptors ' REPRODUCED BY OF U.S. DEPARTM COE MMN ERT CE . NATIONAL TECHNICAL INFORMATION SERVICE SPRINGFIELD SPRINGFIELD VA 22161 3 ee b identifiers Terms Survey Author Survey Study 152-20B Publication Airborne Region Repair Fibrous inhalation quality sampling control Asbestos C. COSATI Group ( 18 Availability Statement ** 239.18 239.18 } 19. Secunty Class This Report | 20. 1 | Security Class This Page See Instructions on Reverse 21. No. Pages 3 22. Price A83 OPTIONAL FORM 12 12 . 272 4- Formerty NTIS Department of Commerce Commerce