a dynamic challenge, for established ones are continually being displaced by newly developed ones more acceptable to food technologists, pharma­ cologists, toxicologists, and changing pest-control requirements in progressive food- producing economies. These matters are also of genuine concern to increasing numbers of governmental agencies and legislative bodies around the world, for some of these chemicals have resulted in a few mishaps from improper use. Adequate safety-in-use evaluations of any of these chemicals persisting into our food­ stuffs are not simple matters, and they incorporate the considered judgments of many individuals highly trained in a variety of complex biological, chemical, food technological, medical, pharmacological, and toxicological disciplines.