Abstract: Employee #1 was preparing a 750/16 inner tube for patching. He had marked the area to be patched, then, taking an air line, attached a hand tool known as an air buffer. The buffer consisted of a graphite stone, 1 inch in diameter by 1 1/2 inches long. This was to be used to clean the surface of the area to be patched. Employee #1 held the air buffer alongside his right leg at the knee. He depressed the trigger to see if it was operating properly and to make sure the air line had not frozen in the low-teen temperatures of the previous night. At the initial onset of air at approximately 90 psi, the graphite stone exploded, sending fragments towards his right eye. Several pieces hit Employee #1 on the right eyebrow, then ricocheted into his right eye. He sustained cuts and bruises to the right eyebrow and stone fragmentation in his right eye.