Abstract: At 9:15 a.m. on January 3, 1992, Employee #1, of Ford Graphics, was replacing an ammonia tank that was used in the diazo department. The tank still contained some ammonia. When Employee #1 disconnected the ammonia tank from the line attached to the manifold, ammonia gas escaped from the tank. Employee #1 was exposed to the ammonia. Suffering eye and upper respiratory tract irritation, Employee #1 missed two to three hours of work. According to the employer's report, Employee #1 removed his goggles and respirator while attempting to stop the leak. According to Employee #1, he never took off his goggles or respirator while he was in the area of the leak; however, he did admit to going outside and removing his respirator for a short period of time to recover. But before returning, he put on his respirator, goggles, and gloves. The accident's causal factors are the following: Employee #1 failed to completely close the valve on the cylinder before disconnecting the line between the cylinder and the manifold; and Employee #1 may have removed his respirator for a short period of time while in the leak area. Employee #1 was trained on how to use a respirator and the correct methods of changing ammonia cylinders.