Outbreaks of acute eye and upper respiratory irritation in poultry processing facilities were examined. Employee complaints of eye and upper respiratory irritation were investigated at six poultry processing facilities in Minnesota, Texas, Louisiana, Missouri, and South Carolina. Burning watery eyes, sneezing, running noses, stuffy noses, and headaches were reported by employees and inspectors at each factory. Blurred vision and photosensitivity were reported at two facilities. Chest tightness and breathing difficulties were also reported. The complaints were generally limited to the evisceration, inspection, and reprocessing areas of the facilities, areas where the largest amounts of chlorinated water were used. A questionnaire survey indicated that more than 80% of the employees in the evisceration, inspection, and reprocessing areas in the South Carolina factory experienced symptoms. Only about 33% of the workers in other areas reported symptoms. The maximum chlorine (7782505) and ammonia (7664417) concentrations detected did not exceed 0.18 and 3 parts per million (ppm), respectively. Since water used at the factories came from chlorinated public water supplies, attention focused on the water. Chlorine concentrations in some of the water samples exceeded the 20ppm required by the USDA to disinfect the processing equipment. All factories reported super chlorinating the chiller water. Trichloramine (10025851) was suspected of causing the symptoms since the complaints first occurred after the local water companies started using trichloramine to treat the water. It was not possible to test for trichloramine due to the lack of an analytical method. The authors conclude that water chlorination practices were probably responsible for the outbreaks. The authors recommend that the level of water chlorination be controlled, and that local exhaust ventilation be provided for superchlorinated water sprays.