Feed contaminant: A substance contaminating animal feed. Contaminants in animal feed can threaten human health.

There are two classes of feed contaminants.

• Contaminants that are naturally occurring -- This class of feed contaminants is made up of toxic or deleterious substances that are inherent constituents of an animal food and that are not the result of environmental, agricultural, industrial or other contamination. Examples of contaminants in this class include:
  • some of the mycotoxins such as aflatoxin and fumonisin;
  • the glucosinolates; and
  • the heavy metals such as lead and cadmium.
• Contaminants that are not naturally occurring -- This class of feed contaminants is made up of industrial toxic or deleterious substances which are increased to abnormal levels in the animal food through mishandling or other intervening acts. Examples of contaminants in this class include:
  • the polychlorinated biphenyls (PCBs); and
  • certain pesticide, like DDT (1,1'-(2,2,2-Trichloroethylidene)bis[4-chlorobenzene]).

The US Center for Veterinary Medicine at the FDA may prohibit any detectable amount of a contaminant or establish a regulatory limit for the contaminant, taking into account the protection of the public health.