Abstract: Employees #1, #2, and #3 were working at the end of a hallway at the rear of a plant in the manganese dioxide cathode area, which was approximately 100 feet from a rear exit door. That afternoon, the door was open. Outside, 100 feet from the door and next to the building, sulfur dioxide was being transferred from a tank truck to a storage tank. At the end of the transfer operation, the hose was disconnected and laid on the ground, spilling a quart of liquid sulfur dioxide on the ground. The wind carried the gas/vapor along the back wall, into the door (the plant is under negative pressure), and down the hallway. An alarm was triggered in the fill room adjacent to the hallway. Employees #1, #2, and #3 evacuated their area but had to travel down the hall through the sulfur dioxide gas. Employees #2 and #3 were hospitalized.