Document 3NJJE7dqRMNjzXJQqd8Drx2m6
FILE NAME Brakes BRK
DATE 1978 Oct
DOC BRK071
DOCUMENT DESCRIPTION Industry Warning Information - Friction Materials
Work Practices Guide
FT Ack
PLAINTIFF'S Ex DepNo o. 22
Date
by JHE
October 1978
FRICTION MATERIALS
WORK PRACTICES
Friction Materials Standards Institute Inc.
USE DUST COLLECTION
EQUIPMENT
WHEN MACHINING
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INTRODUCTION
The purpose of this booklet is to provide practical guidelines for brake and clutch service mechanics in the handling and processing of asbestos containing friction materials and in the maintenance and repair of brake and clutch assemblies on which
the materials are installed
Adherence to the recommended work practices will reduce employee exposure to airborne concentrations of asbestos dust and will assist employers in complying with government regulations
This area is regulated by federal state and local authorities We caution that you may not rely on strict adherence to the work practices recommended herein as assuring compliance with these regulations because a they are subject to amendment b there are going administrative interpretations of these regulations and c particular field conditions may vary You should direct all questions relating to compliance with regulations to the appropriate regulatory agencies
ASBESTOS AND FRICTION MATERIALS
Most molded friction materials contain about 50 asbestos- asbestos-
some woven materials over 90 In molded materials resin binders prevent the release of asbestos fibers during normal handling Woven friction materials normally used only in construction and industrial applications must be handled with care avoid creating dust as the asbestos fibers are less firmly bound into the product
Potentially hazardous airborne concentrations of asbestos dust can be created by improper cleaning and handling of worn brake and clutch assemblies uncontrolled machining operations and poor housekeeping
Breathing excessive quantities of asbestos fiber can cause respiratory disease and cancer Smoking greatly increases the risk of lung cancer among asbestos workers Prevention of asbestos dust exposure is the only known method of eliminating asbestosrelated disease among those working with asbestos containing products
Proper work practices offer the best assurance of providing
exposure safeguarfdosr workers removing installing and machin-
ing asbestos containing friction materials
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SUMMARY OF OSHA ASBESTOS STANDARD
EFFECTIVE JULY 1 1976
Under the current standard it is the employer's responsibility to assure that exposure of employees does not exceed the following permissible exposure levels
a Eight weighted average Two fibers longer than five micrometers per cubic centimeter
b Ceiling Peak concentrations Ten fibers longer than five
micrometers per cubic centimeter
Engineering controls such as isolation enclosure exhaust ventila-
tion and dust collection are the preferred methodfosr meeting the
prescribed exposure limits All external surfaces must be main-
tained free of asbestos fiber accumulation
Respiratory protection is required whenever airborne fiber concentrations exceed either the permissible time weighted average level or the permissible ceiling concentration Protective clothing is required whenever airborne fiber concentrations exceed the permissible ceiling level Caution signs change rooms and employee notification are required where asbestos fiber concentrations exceed permissible exposure limits The standard requires that all workplaces where asbestos fibers may be released shall be monitored to determine exposure levels and regular monitoring is required where exposure levels are expected to exceed permissible limits Employers must maintain records of monitoring required by the standard They must also provide or make available medical examinations for employees exposed to
airborne concentrations of asbestos fibers 5
USE VACUUM OR WET METHODS
FOR CLEANING
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HANDLING NEW FRICTION MATERIALS
Handling new disc brake assemblies lined brake shoes clutch facings and brake blocks purchased in individual boxed sets is unlikely to create significant airborne concentrations of asbestos dust If the parts are purchased in bulk quantities abrasion during shipment may result in the accumulation of dust in shipping containers Dust should be removed by vacuuming or cleaning with a damp cloth
Whenever possible purchase friction materials preground and ready for installation This may keep dust levels below OSHA maximums and eliminate the need for respiratory protection restricted areas regular monitoring special clothing change rooms and employee notification
REMOVING WORN FRICTION MATERIALS
Asbestos fibers in disc brake linings drum brake linings blocks and dry clutch facings are locked into the product with resin binders which prevent the release of asbestos fiber during normal installation Heat and abrasion during normal use may generate dust containing asbestos Some dust will accumulate in brake and
clutch assemblies
When removing worn friction materials remove the accumulated
dust in the assemblies with an industrial vacuum cleaner
equipped with a high efficiency filter system If such equipment not available dust can be removed with a damp cloth Do not use compressed air or dry brushing for cleaning
Use a NIOSH approved respirator when removing worn friction materials or cleaning brake or clutch assemblies
MACHINING FRICTION MATERIALS
There is an increasing trend for manufacturers and rebuilders to provide brake lining and clutch facings drilled and ground in final assembly form In the case of truck brake blocks various oversize thicknesses are available However there are some instances where field machining is necessary This is particularly
true for construction and industrial equipment applications which
may require machining of blocks slab stock or roll lining
Dust generation can be minimized or eliminated during arcing of brake blocks by lathe turning at low speed rather than grinding
Whenever possible friction materials should be cutto length with a
shear rather than a saw or abrasive cut wheel 7
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METHOD
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DUST COLLECTION METHODS
When containing friction materials are machined i.e
drilled ground grooved cut or beveled the dust created contains **
asbestos fibers which may become airborne unless adequate dust controls are employed The preferred method for minimizing airborne dust from machining operations is local exhaust ventila-
tion A local exhaust ventilation system consists of dust collection
hoods or enclosures connected by duct work or piping to a dust
collection filter and a suction source
.
The two operations that offer the greatest potential for generation
of excessive amounts of airborne asbestos fiber are arc grinding and beveling of lined brake shoes and linings or brake blocks
Grinding machines used for these operations must be provided
Iwith exhaust ventilation to maintain worker exposures within
permissible levels
If a central exhaust system is not available NIOSH National Institute for Occupational Safety and Health has stated that at a miminum the dust bag of the arcing machine shall be removed and replaced with the hose from a high efficiency industrial
vacuum
For large volume machining operations that operate on a continuous basis the preferred dust collection device is a fabric filter
or baghouse with a heavy exhaust fan as the suction source The dust collector must meet the cleaning requirements of the Federal Environmental Protection Agency Emission Standard for Asbestos Approval must be obtained from EPA for installation and
operation of each system
OTHER METHODS OF MINIMIZING DUST
EXPOSURE
Whenever possible machining and repair operations should be
isolated from other work areas in a restricted area to prevent unnecessary exposure of other workers Entrances to restricted areas shall be posted with asbestos exposure warning signs as follows
.
Asbestos
Dust Hazard
Avoid Breathing Dust Wear Assigned Protective Equipment Do Not Remain In Area Unless Your Work Requires It
Breathing Asbestos Dust May Be Hazardous To Your Health
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RESPIRATOR RESPIRATOR RESPIRATOR
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Good housekeeping is essential in a workplace where asbestos ** containing materials are handled Industrial vacuum cleaners equipped with multiple stage high efficiency filters should be used
for removing accumulations of asbestos dust and waste
Never use compressed air or dry sweeping for cleaning Water or
2
other dust suppressants should be applied if brooms are used
Good personal hygiene practices are important in minimizing
.
asbestos dust exposure Do not smoke Wash before eating
Shower after work Change to work clothes upon arrival at work and
change from work clothes at conclusion of work Work clothing should not be taken home Laundering of asbestos contaminated
clothing shall be done so as to prevent the release of airborne
asbestos fibers in excess of the exposure limits
AVOID AVOID DUSTDUST
=
DISPOSAL OF FRICTION MATERIAL DUST AND WASTE
containing Dispose of vacuum cleaner waste and asbestos
cleaning materials in plastic bags or other sealed containers with the following warning label printed on the container
ES Caution
Contains Asbestos Fibers
Avoid Creating Dust Breathing Asbestos Dust May Cause Serious Bodily Harm
Use a NIOSH approved respirator when servicing vacuum cleaners dust collectors or handling any containing
waste materials
,
containing waste materials must be collected processed packaged transported and deposited in such fashion that no visible emissions are generated to the atmosphere All wastes must be disposed of at sites operated in accordance with applicable laws and regulations
SOURCES OF ADDITIONAL INFORMATION
Standard for Exposure to Asbestos Dust Code of Federal Regulations Title 29 1910.1001
National Emissions Standards for Hazardous Air Pollutants and Mercury Code of Federal Regulations Title 40 Chapter 1 Subchapter C Part 61 Subparts A -EPA
Fundamentals Governing the Design and Operation of Local Exhaust Systems ANSI Z9.2-1971 $ 00 and Practices for Respiratory Protection ANSI Z88.21969 -ANSI
Industrial Ventilation Manual -ACGIH
For other information a user may contact the manufacturer supplying his friction materials the Asbestos Information Association or the Friction Materials Stand-
ards Institute
ACGIH American Conference of Governmental
Industrial Hygienists Committee on Industrial Ventilation PO Box 16153 Lansing MI 48901
ANSI American National Standards Institute 1430 Broadway New York NY 10018
AIA Asbestos Information Association
1745 Jefferson Davis Highway Arlington VA 22202
EPA Environmental Protection Agency Public Information Center 401 M Street SW Washington DC 20460
FMSI Friction Materials Standards
Institute East 210 Route 4 Paramus NJ 07652
OSHA
Occupational Safety and Health Administration
Office of Information Washington DC 20210
October 1978