generally recognized as safe (GRAS), a 1958 rule established by the U.S. Food and Drug Administration (FDA) to identify foods regarded as safe to use because of lack of evidence that they may be harmful. Originally the rule was applied to all foods that were in use in 1958 and were not then known to be hazardous. Later, because of improved scientific techniques for detecting mutagens and carcinogens, items that had been classified as safe, such as caffeine, were further tested by the FDA to determine whether they should remain on the GRAS list.
