Abstract: On October 3, 1990, two employees mixed incompatible food additives and/or too much sodium metabisulfite. The food additives were mixed improperly because the employees lacked hazard communication training and/or familiarity with the English language. The MSDS for sodium metabisulfite stated that "oxidizers may cause strong exothermic reactions" and that "acids yield sulfur dioxide gas, which is toxic and corrosive. Water increases the natural rate of yield of sulfur dioxide gas." Based on this information, it would be reasonable to assume that the addition of citric acid and water to sodium metabisulfite would cause the release of sulfur dioxide. The employees working in the area noticed a strong odor and began to experience adverse effects: watery, irritated eyes, a swollen, itchy tongue, difficulty breathing, respiratory irritation, vomiting, dizziness, and headaches. The local fire department was called. About 150 employees were evacuated from the building. About 43 employees were transported to area hospitals. Employees #1 through #12 were hospitalized for one to seven days.