Technicians in a facility where brake and clutch work are done – as well as anyone else in the area — may be exposed to asbestos dust. Some brake dust can be seen when a brake drum is removed from the car, truck, or other equipment. But there are also many very small dust particles that can’t be seen with the naked eye. These invisible particles may be asbestos or other brake lining materials, and breathing these particles can damage your health. Many years after breathing asbestos particles may cause shortness of breath, lung disease, or cancer. Asbestos is only one of many materials used in brake linings today. The only sure way to know what is in the dust from a particular brake is to test it in a laboratory. Since some newer brake lining materials are still being tested, caution is necessary. The only practical way to protect your health and those around you is to control the release of brake dust in your garage to the lowest level possible.

Cleaning Methods That Release Brake Dust Into the Air
Air Hose. Don’t blow brake dust! Never use an air hose for cleaning! This blows brake dust into the air, which is one of the worst things you can do. When brakes are cleaned with an air hose, invisible particles of brake dust can stay in the air long after a brake job has been finished. Any other activity in the brake work area can stir up the particles that have settled.

Other Methods. Also not recommended are cleaning brakes with a dry brush or rag, wet brush or rag, garden hose, liquid squirt bottle, solvent spray, or ordinary shop-vac. These methods will also stir up visible and invisible brake dust. Many of these dust particles are so small that they can pass through the filter bag of an ordinary vacuum cleaner and spread throughout the garage.

Controlling Brake Dust
Vacuum/Enclosure Method. A vacuum/enclosure system has a special box with clear plastic walls or windows, which fits tightly around a brake assembly. Some boxes can even fit over a brake drum. Good brake cleaning can be done without exposing technicians or contaminating a garage.

A special air gun inside the box is used for cleaning. An exhaust hose goes from the box or drum to a special HEPA (High Efficiency Particulate Air) asbestos vacuum cleaner, which draws out and stores the brake dust. The manufacturer’s instructions should be carefully followed when using this system and/or changing the filters or collection bags. Improper maintenance can release dangerous amounts of asbestos into the air.

Steps for using this type of equipment on brake drums are simple:

1. Check that the hose is securely fastened to the HEPA vacuum container and to the brake enclosure. Also check that the vacuum container seals and clips are in proper functioning order according to the manufacturer’s instructions.
2. Remove the wheel.
3. Turn on the asbestos vacuum cleaner.
4. Place the enclosure over the drum, being sure it forms a tight seal behind the backing plate.
5. Place hands into the attached rubber gloves, if the enclosure is equipped with them.
6. Remove the brake drum. Some equipment allows the use of a hammer or other tools when needed inside the enclosure for drums that are hard to remove.
7. Blow dust off the drum and brake assembly using the air gun attachment inside the enclosure.
8. Clean all inside surfaces of enclosure towards the vacuum exit, using the air gun attachment inside the enclosure.
9. Remove the enclosure and turn off the vacuum cleaner.

Wet Methods. Using specially contained low pressure spray equipment that wets down brake dust and properly catches the runoff may prevent some asbestos from spreading. Be sure to use only the liquid recommended by the manufacturer.

Waste. All waste that contains brake dust must be carefully disposed of according to federal and local regulations for asbestos materials. Asbestos waste should be placed in specially marked, heavy plastic bags, double tied, and stored in a leak-proof, airtight container designated for asbestos waste.

Special Areas for Brake Work. Where practical, brake work should be done in a special area set apart from other work areas. No one should eat, drink, or smoke in an area where brake work is done. Smokers who are exposed to asbestos, even while they are not smoking, are at especially high risk of getting lung cancer. If possible, work clothes should be laundered at special facilities equipped to wash clothing contaminated with asbestos.
(Source: U.S. EPA, Office of Pollution Prevention)