It is virtually impossible to anticipate all of the hazards involved with automotive maintenance and service, but care and common sense will prevent most accidents.
The rules of safety for mechanics range from "don't smoke around gasoline," to "use the proper tool(s) for the job." The trick to avoiding injuries is to develop safe work habits and to take every possible precaution.
Fig. Screwdrivers should be kept in good condition to prevent injury or damage that could result if the blade slips from the screw
Fig. Power tools should always be properly grounded
Fig. Using the correct size and standard (metric or SAE ) wrench will help prevent the possibility of rounding off a nut
Fig. NEVER work under a vehicle unless it is supported using safety stands (jackstands)