Abstract: On February 23, 1999, Employee #1 was using a General Electric Burr King belt sander to remove a burr from the handle of a Shop-Aid tool he was holding. A sudden energy release from the Shop-Aid tool caused it to fragment, injuring the bone and tissue of Employee #1's right hand. He was administered aid by a coworker until the employer's Emergency Response Team arrived. Employee #1 was transported to UC-Davis Medical Center, where he underwent surgery. He also experienced some hearing and balance impairment, which continued to be evaluated after he was allowed to returned to work, with restrictions. Subsequent investigation by Cal/OSHA found several problems: failure to decontaminate the Shop-Aid tool with a bake-out oven before taking it from the manufacturing area to the machine shop; lack of training for the machine shop supervisor on decontamination of tools and equipment; the poor design of the Shop-Aid tool; and inadequate information on the MSDS about how to handle contaminated tools and equipment during repairs and maintenance.