Abstract: About 11:00 a.m. on May 15, 1991, Employee #4 was cleaning a 12 ft by 24 ft chemical cage. A barrel of mixed phosphoric and nitric acid was in the middle of a pallet in the cage. Employee #1 took hold of the top of this unopened 55 gal plastic barrel and moved it about 4 in. The bottom of the barrel split and the liquid contents leaked onto the cage floor. This liquid spread over the floor, and got on Employee #4's shoes. Employee #4 then went 4 ft to a nearby faucet and washed off his legs and shoes. At this time, Employee #2 was walking 4 ft from the spill and saw the liquid running from under the side of the cage. He instructed a maintenance man, Employee #9, to get the absorbent "pigs" and dam and contain the spill. Employee #3 was getting parts 20 ft away and saw the liquid rush out and gases start to form. Employee #1 was informed of the spill and proceeded to the area. By this time, the acid was reacting with the cement and also with spilled flux on the floor. A larger gas cloud developed and began to expand. Employee #1 told all nearby employees to evacuate the area and building. Employee #5 was working 50 to 60 ft away and could smell a stronger than normal odor. She went outside when instructed. Employee #6 was working outside the door and he helped to make a dam with absorbent pigs to contain the acid. The acid was now bubbling and smoking on the floor and Employee #6 was exposed to the vapors forming. Employee #7 had been told to leave, and was 60 ft away when a fan started to blow vapors at him, and his nose started to burn. Employee #8 was at the chemical cage and was getting everyone out of the building when he was exposed to vapors generated by the spill. The fire department was called, and all nine employees went to the local hospital on the instruction of top management. The plant was closed and no one was allowed back into the building.