Never refuel a hot motor, and disconnect the mower's spark plug prior to refueling. While string trimmers can be very helpful, they also can cause many injuries if they are not used properly. Eye injuries are the most frequent and severe type of injury, so a full-face shield should be worn to protect the operator from flying debris. These trimmers also are very noisy, so hearing protection must be used. Leather-topped shoes should be worn to protect the user's feet from flying stones.
Trimmers require daily maintenance too.
Fuel, oil and other fluid levels must be checked as required by the instructions. Trimmers often require oil in the fuel system, so directions must be followed closely to obtain the proper mix. Guards always must be secured during operation. Check to be sure that the recommended trimming line is on the spool, too. When starting a string trimmer, lay it flat on the ground and make sure no one is nearby.