An outbreak of illness after occupational exposure to ozone and acid chlorides

New labelling processes installed without adequate ventilation control in an electric motor factory exposed production line workers to toxic gases. Symptoms of eye and respiratory tract irritation together with complaints of headache, fever, chills, dizziness, malaise, general weakness, nausea, and vomiting were widespread. Chest signs, radiographic abnormalities, reduction in ventilatory function, and blood gas abnormalities were found in some cases. Epidemiological analysis of the spatial and temporal distribution of cases supported an exposure effect relationship. Investigations suggested ozone and possibly phosgene and associated trichloroacetyl chlorides as the toxic agents that were generated by an ultraviolet print curing arrangement and perchloroethylene used as a cleaning solvent.