Abstract: On September 14, 2000, Employee #1 was conducting an inspection of the cleaning process on the 2nd stage Duall Tank. The cleaning operation entails the draining of the tank, which is a solution of sodium hypochlorite, sodium hydroxide and water. It is then flushed with water and then a solution of water and sulfuric acid is introduced to clean the tank. The cleaning process continues for 12 hours. The tank is then drained again and flushed before new solution is added. Employee #1 removed the inspections doors and flashing into the tank to see that all of the circulation lines were properly operating. Gloves, aprons and safety glasses were worn. When he removed the upper door, he was immediately exposed to a chlorine odor that took his breath away. He was immediately lowered from the area and he ran outside and was hospitalized.