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  5. Biological, Chemical, and Physical Contaminants in Animal Food
  6. Chemical Contaminants
  1. Biological, Chemical, and Physical Contaminants in Animal Food

Chemical Contaminants

Chemical contaminants cover a broad range of contaminants, including naturally occurring components of certain food ingredients (e.g., glucosinolates), toxins produced by microorganisms found in the environment (e.g., mycotoxins), pesticides, and industrial chemicals. CVM routinely monitors many chemical contaminants under its Animal Food Contaminants Program, like mycotoxins, pesticides, dioxins, and trace elements.

On this page:

Mycotoxins

  • Aflatoxins
  • Deoxynivalenol
  • Fumonisin
  • Ochratoxin A
  • Zearalenone

Pesticides

Environmental Contaminants

  • Per and Polyfluoroalkyl Substances (PFAS)
  • Dioxins/PCBs

Trace Elements

Miscellaneous Contaminants

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Mycotoxins

Mycotoxins are toxic metabolites of certain fungi (molds) that can grow on agricultural commodities in the field and during storage. The occurrence of these toxins on grains, seeds, and complete animal food is influenced by various environmental factors, such as temperature, humidity, and rainfall during growing, harvesting, and storage. When fungal growth occurs, mycotoxins are produced in commodities; some of which are used in animal food. The mycotoxins will then remain in the food throughout every phase of food production. Mycotoxins are difficult to eliminate because they are not destroyed by most of the processes used in animal food production. When consumed by animals or humans, the results can be detrimental, resulting in illness or even death. The effects of mycotoxins can manifest in a variety of ways, including neurologic impairment, liver, kidney, or heart failure. 

To prevent mycotoxins from becoming an animal health hazard, animal food manufacturers are required to conduct a hazard analysis that identifies potential hazards within the manufacturing process and provide evidence of consistent monitoring and preventive controls for mycotoxins in animal food.

Aflatoxins

Aflatoxins are produced by molds of the Aspergillus species. Aflatoxins are among the most well-known mycotoxins due to their high level of toxicity in many animals and people. Aspergillus can grow on grains and seeds during growing season as well as after harvest during storage. The amount of fungal growth and the resulting aflatoxin level in food ingredients is influenced by the temperature and humidity and can vary from year to year. 

Aflatoxins are potent toxins and known carcinogens, so their levels in food should be limited to the lowest practical level. Aflatoxins are also known to cause liver damage and liver failure in animals. Animals that consume aflatoxin-contaminated food can also transfer the toxins to meat, milk, and eggs, potentially exposing humans to a health hazard.

Deoxynivalenol

Deoxynivalenol (DON, or vomitoxin), is produced by Fusarium graminearum, a mold commonly associated with grains such as wheat, barley, oats, and corn.

Its most notorious disease commonly affects wheat and is known as Fusarium Head Blight (FHB). Infestation can occur throughout the cultivation process and generally initiate decomposition. If wheat infested with fusarium mold makes its way into the diets of humans, it may cause symptoms such as vomiting, diarrhea, abdominal pain, headaches, dizziness, fever, and it may cause immunological issues. Animals, too, will suffer from vomiting and abdominal pain. In animals, swine are the most susceptible.

Fumonisin

Fumonisins are toxins produced by various molds of the Fusarium genus (e.g., F. moniliforme, F. verticillioides, and F. proliferatum) that are common, natural contaminants of corn. Fumonisins can cause leukoencephalomalacia in horses and pulmonary edema in pigs. They have been linked to a variety of significant adverse health effects in other livestock and experimental animals. Fumonisin B1 is known to induce kidney tumors in male rats and liver tumors in female mice when they consume food containing 50 ppm fumonisin and above. A wide variety of significant adverse animal health effects such as neurological symptoms, cardiopulmonary failures, and kidney failure have been associated with fumonisins. Horses are extremely susceptible to the harmful effects of fumonisins.

Ochratoxin A

Ochratoxin A is a fungal toxin produced by molds in the Aspergillus and Penicillium families. Ochratoxin A can be produced in peas and cereals grains such as corn, wheat, barley, rice, and sorghum during improper storage. Although most fungi are destroyed when food is properly cooked, ochratoxin A, produced by the molds, is resistant to heat.

While ochratoxin A is acknowledged as a carcinogen in mice, several toxic effects in animals, namely nephrotoxicity, have been recognized following exposure to ochratoxin A as well as negative impacts in the performance of farm animals.

Zearalenone

Zearalenone (ZEA) is produced by the growth of the fungus Fusarium graminearum on food commodities. This mold grows best on foods during periods of low temperatures coupled with high humidity, although it can grow during other weather conditions as well. When animals or humans are exposed to zearalenone at low levels for brief periods there may not be any visible symptoms, as ZEA has a low toxicity. However, when the toxin is present in food at high levels or when there is long term exposure at low levels, it can cause reproductive disorders.

Guidance

Assignments/Reports

Additional Information

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Pesticides

Section 408 of the Federal Food, Drug, and Cosmetic Act (FD&C Act) authorizes the U.S. Environmental Protection Agency (EPA) to set tolerances, or maximum residue limits, for pesticide residues on foods. Under the FD&C Act, FDA has the responsibility to enforce EPA-established pesticide tolerances in foods imported into the United States and domestic foods shipped in interstate commerce (with the exception of meat, poultry, and certain egg products, regulated by the Food Safety Inspection Service of the U.S. Department of Agriculture). To accomplish this task, both the Center for Food Safety and Applied Nutrition and CVM manage a Pesticide Residue Monitoring Program. Each year, FDA investigators collect a variety of animal food samples as part of CVM’s Animal Food Contaminants Program and sends them to the Office of Regulatory Affair’s laboratories for pesticide analysis. This program allows FDA to gather information on pesticide residues in animal foods and food ingredients, thereby protecting both human and animal health.

Guidance

Assignments/Reports

Additional Information

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Environmental Contaminants

Per and Polyfluoroalkyl Substances (PFAS)

Per and polyfluoroalkyl substances (PFAS) are a family of chemicals that have the ability to resist grease, oil, water, and heat, making them useful in a number of consumer and industrial products. These chemicals are characterized by the presence of one or more carbon-fluorine bonds, which are very strong and not easily broken. PFAS have been found to be ubiquitous in the environment including in air, water, and soil, providing a potential mechanism for human and animal exposure through food and drinking water.

There are no tolerances or other administrative levels established by the FDA for PFAS in animal food. FDA actively collaborates with state and other federal government agencies to review the growing body of data and research on PFAS to protect human and animal health.

Additional Information

Dioxins/PCBs

Dioxins and polychlorinated biphenyls (PCBs) are persistent environmental pollutants resulting from industrial processes. Their toxicity varies, but some of the dioxin and PCB congeners may be carcinogens at low levels of exposure over extended periods of time.

There are no tolerances or other administrative levels established by the FDA for dioxins in animal food. FDA, in conjunction with the U.S. EPA and USDA, address dioxin concerns in animal food on a case-by-case basis. 

Temporary tolerances for PCBs in animal food can be found in 21 CFR 509.30.

Guidance

Additional Information

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Trace Elements

Trace elements are inherent to the environment and can be both helpful and harmful, nonetheless, they are frequently present in animal food. Under the Animal Food Contaminants Program, the FDA routinely tests animal food, including pet food, for essential and non-essential trace elements.

There are two types of trace elements that are regulated.

  • The first type is essential to the animals’ health and can be described as “nutritional elements”. These elements serve various roles and are required for optimal health (including weight gain, production, and ability to fight off diseases). Inadequate supply of these essential elements can result in reduced production, illness, or death. Examples of nutritional elements are copper, zinc, selenium, and iron. However, when present in excess these elements can also cause harm.
  • The second type is non-essential (toxic) and consists of elements that have no physiologic role in the body and can be harmful if consumed in excess. At low concentrations in the diet, these elements may be tolerated by the animal, but can cause harm to humans when the animal products are consumed. Examples of non-essential (toxic) elements are arsenic, cadmium, mercury, and lead and are sometimes referred to as heavy metals. 

Assignments/Reports

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Miscellaneous Contaminants

In addition to the types of chemical contaminants listed above, CVM also monitors for contaminants that fall outside of these categories, including emerging contaminants. Examples of miscellaneous chemical contaminants that have been found in animal food include pharmaceuticals and melamine and its analogues.

Assignments/Reports

Additional Information

 

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