To the Editor: The “primer for physicians” on food technology (March 7 issue)1 was useful but omitted important information about food additives that could be of lifesaving value to patients. The authors inadequately convey the risk posed by sulfites by stating only, “allergic reactions. have occurred.” In fact, since 1982 at least five deaths have been linked to the use of this cosmetic preservative in restaurant foods.2 All the victims had asthma. Nine, not five, synthetic dyes are currently permitted by the Food and Drug Administration. One of the dyes (Orange B) contains a carcinogenic contaminant and is no.