In food safety policy, a zero tolerance standard generally means that if a potentially dangerous substance (whether microbiological, chemical, or other) is present in or on a product, that product will be considered adulterated and unfit for human consumption. In the meat and poultry inspection program, zero tolerance usually refers to USDAs rule that permits no visible signs of fecal contamination (feces) on meat and poultry carcasses.
Diseases that under natural conditions are communicable from animals to humans. Anthrax, Brucellosis, Psittacosis, Rabies, Tuberculosis, and Tularemia are example of zoonotic diseases. Brucellosis in livestock becomes undulant fever in humans.