Abstract: Employees #1 through #4 were working in a plant in which a prelete dip tank had been malfunctioning for two months. The high-heat shut-off valve was not working or attached to the tank, which contained 1,1,1, trichloroethane. When the hot side boiled down, exposing the heat elements, the tank began to smoke and the alarms went off. Employees were coughing and feeling ill but did not leave the building when the alarms sounded. The fire department arrived and opened the remaining doors to ventilate the building. When the paramedics arrived, they transported Employees #1 through #4 to the hospital, where they were treated and released. The owners of the company arrived and inspected the area inside for a half an hour. Not smelling anything, they sent the employees back to work.