Do keep a fire extinguisher and first aid kit handy.Do wear safety goggles when cutting, drilling, grinding or prying, even if you have 20/20 vision. If you wear glasses for the sake of vision, then wear safety goggles over your glasses.Do shield your eyes whenever you work around the battery. Batteries contain sulfuric acid; in case of contact with the eyes or skin, flush the area with water or a mixture of water and baking soda and get medical attention immediately.Do use jackstands for any undercar service. Jacks are for raising vehicles; jackstands are for making sure the vehicle stays raised. Whenever the vehicle is raised, block the wheels remaining on the ground and set the parking brake.Do use adequate ventilation when working with chemicals. Like carbon monoxide, asbestos dust resulting from some brake lining wear can be poisonous in sufficient quantities.Do disconnect the negative battery cable when working on the electrical system. The secondary ignition system can contain up to 50,000 volts.Do follow manufacturer's directions whenever working with potentially hazardous materials. Most fluids are poisonous if taken internally.Do maintain your tools. Loose hammerheads, mushroomed punches and chisels, frayed or poorly grounded electrical cords, excessively worn screwdriver's, spread wrenches (open end), cracked sockets, slipping ratchets, or faulty droplight sockets can cause accidents.Do use the proper size and type of tool for the job at hand.Do when possible, pull on a wrench handle rather than push on it, and adjust your stance to prevent a fall.Do be sure that adjustable wrenches are fit tightly on the nut or bolt and are pulled so the force is on the fixed jaw.Do select a tool that fits the nut or bolt. The wrench or socket should sit straight, not cocked.Do strike squarely with a hammer - avoid glancing blows.Do set the parking brake and block the drive wheels if the work requires that the engine be running.