In addition to pathogens, chemical additives to food are of increasing concern to Americans. A critical concept related to chemical additives in food is known as generally recognized as safe or GRAS, a designation of the Food and Drug Administration for food substances that are exempt from safety testing. About 12,000 samples of fruits and vegetables available to U.S. consumers are collected each year and tested for residue from pesticides, and the results are published in an annual Pesticide Data Program (PDP) hosted by the USDA.