Abstract: At approximately 8:30 a.m. on September 3, 1997, thirty employees at a clothing manufacturing plant experienced various symptoms as a result of an ammonia spill. The thirty employees were transported to area hospitals however none were treated or admitted. The incident occurred when a maintenance employee spilled about one gallon of a 30-percent ammonia solution while setting up a new 72 in. blueprint machine that had been recently installed. The maintenance worker stated that a line was blocked, causing the spill. The worker cleaned the spill after all employees were evacuated from the building. He did not wear a face shield or other eye protection. He stated that he had experienced no ill effects from the exposure, and was able to clean up the spill without experiencing any respiratory distress. The building in which the incident occurred is at least ten thousand square ft, with a ceiling height ranging from 20 ft to 30 ft. Employee #1, one of the workers who experienced mild symptoms of exposure, was more than 50 ft away, in the sewing production line. Workers within 50 ft of the spill did not have problems. A spill of ammonia can be very serious, and there was a potential for up to ten gallons to be spilled from this operation. However, a spill of one gallon in a well-ventilated, two hundred thousand cubic foot building, is unlikely to cause serious health problems to employees located more than 50 feet away.