Sulfiting agents including sodium and potassium bisulfite and metabisulfite, sulfur dioxide, and sodium sulfate are recently identified food and drug adverse responsible for adverse reactions such as flushing, tingling, pruritis, urticaria, glottic edema, dysphagia, chest tightness, acute bronchospasm, cyanosis, and loss of consciousness. Foods which contain metabisulfite are listed in Table I. Metabisulfites are also present in some drugs such as aerosolized bronchodilators. The pathogenic mechanism is unknown. Approximately 3-5% of the asthmatic population reacts adversely to these sulfites. The FDA has recently recognized this potential hazard and a ban on the use of sulfiting agents in restaurants is being considered.