Abstract: At 9:00 a.m. on May 22, 2013, an employee was working alone in the Control Room of Ammonium Poly Phosphate (APP) manufacturing process. The employee was in the process of starting up the process after a short shut down. The anhydrous ammonia globe valve was turned back on and the water flush valve had been left open with the two water lines closed. Ammonia exothermically reacted with the water in the line and built up temperature and pressure in the water line. The PVC valve in the control room was not designed to handle ammonia (only water) and it failed under the temperature and pressure in the line releasing anhydrous ammonia and hot water on the employee. The door exiting the control room was locked from the inside and the employee was found unconscious next to the door. The employee had first and second degree chemical and/or thermal burns on 79-88% of the total body surface area and died.