Abstract: An employee was mixing paint with light hydrotreated petroleum naphtha (CAS No. 64742-49-0). As directed by his employer, he was using a Milwaukee Magnum Hole-Shooter drill (Model No. CIJD; Serial No. 592 191 4567) with a mixing attachment to mix the paint. The electric drill ignited vapors from the solvent, and the ensuing explosion burned the employee's hand. He was hospitalized for 1 week at a burn center with two skin-graft surgeries. The injured employee, who had not been following the owner's manual instructions not to use the drill in the presence of flammable atmospheres, was not adequately trained in the material safety data sheet for the solvent or in the precautions in the power tool owner's manual.