A 1,000-gallon propane tank was being refurbished. It had been hoisted into the air using a propane forklift truck. An employee checked the valves of the tank while it was lifted in the air, then turned on the forklift to reposition the tank. This ignited vapors from the tank, and the employee suffered burns to the back, left arm, and face in the resulting flash fire. Flame-resistant clothing was not being worn at the time.