Acute inhalational exposure to chlorodifluoromethane (freon-22): a report of 43 cases.

We report 43 cases of chlorodifluoromethane (Freon-22) intoxication that occurred on August 5, 2003 when a freezer in a seafood factory exploded. In this accident, 80 workers were exposed to Freon-22 gas and 43 workers developed symptoms and were transferred to six hospitals. Neurological symptoms including dizziness, headache, and nausea were most frequently observed (40 of 43 patients). One patient was comatose but recovered within 1 h with oxygen inhalation. Airway and respiratory symptoms including dysesthesia of the tongue, pharyngitis, and shortness of breath were also frequently observed (26 of 43 patients). These symptoms disappeared within a few days in all patients. There were no fatalities. Although Freon-22 has been considered to be a chlorofluorocarbon of relatively low toxicity, this incident suggests that potentially significant toxic effects may occur following large exposures.