Abstract: On September 16, 2009, Employee #1, a painter, was applying initial coats of paint to the baseboards and the cabinets in a master bathroom that covered an area of approximately 240 square ft. The mixture of paint included 3 to 5 gallons of Valtec Pre-Catalyzed White Lacquer Undercoat (45 to 50 percent acetone) and 1 to 6 ounces of lacquer thinner (32 to 48 percent acetone). Employee #1 was using an airless paint sprayer (Spraytech Model Number 650) to apply the paint. The grounding contact pin was missing from the sprayer's power cord. The ventilation in the room included a box fan at a window located adjacent to the bathroom, and a portable local exhaust ventilation unit (Grainger, two-speed, 1120 CFM high setting, and 877 CFM low setting) located on the floor about 10 feet away from the bathroom. Employee #1 had applied two coats of the paint mixture, and was on his third application while crouched down at the entrance of the bathroom. Employee #2, his supervisor, was located about 24 ft away patching and sanding. He was also checking Employee #1's work and was available to assist Employee #1. When a flash fire occurred, Employee #2 extinguished it with a fire extinguisher. Employee #1, who was wearing shorts, sustained third-degree burns on both of his legs from the mid-calf to the ankles and second-degree burns on his right arm and hand. Employee #2 sustained respiratory injuries. Both employees were admitted to the Western Medical Center Hospital.