Center for Asbestos Safety in the Workplace
Brake Repair Safety Guide
Brakes are a small part of a car, but working on them can pose hazards because of the asbestos content and the complex shape of the brake systems.
OSHA recommends two basic containment methods for brake and clutch repair in order to reduce exposure: the Low Pressure/Wet-Cleaning method and the Negative Pressure Enclosure/HEPA Vacuum System.
The wet-cleaning method involves application of water, but at a low enough pressure that doesn't unnecessarily disturb the asbestos-containing material.
The idea is to ensure that the asbestos is sufficiently wet so that air concentration of fibers are kept well below the permissible exposure limits. The solution can consist only of water, or water mixed with an organic solvent, or a detergent. It is important to note the potential danger of solvent use in these operations. The use of solvents, which are often flammable and may also present a health hazard, must be undertaken with great care. The employer must also comply with the Hazard Communication standard.
The mechanic/technician may use a pump sprayer (bottle) containing water or other liquid to wet down the drum or clutch housing before it is removed and to control fiber release during subsequent activities. The mechanic can use a hose to spray down the brake assembly, but must make sure the resulting wastewater is captured and properly disposed of without allowing it to dry on any surfaces.
Some practitioners use a solvent method that works safely when proper work practices are followed. If a solvent spray method is used, it must include the following
- the solvent must first wet the brake and clutch parts
- the brake and clutch parts must be wiped clean with a cloth
- the contaminated cloth must be placed in an impermeable container, and then either disposed of properly or laundered in a way that prevents the release of asbestos fibers in excess of 0.1 fiber per cubic centimeter of air
- any spilled solvent or dispersed asbestos must be cleaned up immediately and not allowed to dry, either with a cloth or a HEPA vacuum. Dry brushing during solvent spray operations is prohibited.
Brake inspections
The extent to which an "inspection" is different from the other brake servicing depends on whether and how the drum is removed. Most inspections of brake shoes involve removing the drum which may contain a substantial number of asbestos fibers. The shop and mechanic must take measure to prevent the release of those fibers into the workplace. If the drum is carefully pulled back just far enough to observe the brake shoe and brake components, it is sufficient to thoroughly wet the exterior and around the seam between the brake drum and backing plate. Any dislodged material must be immediately cleaned up.
If the mechanic hits the drum with a hammer or similar implement to dislodge a rusted-in-place or frozen drum, asbestos fibers could be released. The government requires that shops that perform six or more brake jobs per week install an enclosure around the drum to capture the dust. Alternatively, the shop can use a procedure where the mechanics thoroughly wet drum interior and contents prior to striking or forcibly removing the brake drum.
The rules for shops that do fewer than five brake jobs a month are less stringent.
Related: Occupational Medicine journal published an article on mesothelioma in Australian mechanics.