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:
- Aflatoxins
- Deoxynivalenol
- Fumonisin
- Ochratoxin A
- Zearalenone
- Per and Polyfluoroalkyl Substances (PFAS)
- Dioxins/PCBs
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
- Guidance for Industry: Action Levels for Poisonous or Deleterious Substances in Human Food and Animal Feed - Aflatoxin Action Levels
- Guidance for Industry and FDA: Advisory Levels for Deoxynivalenol (DON) in Finished Wheat Products for Human Consumption and Grains and Grain By-Products used for Animal Feed
- Guidance for Industry: Fumonisin Levels in Human Foods and Animal Feeds
Assignments/Reports
Additional Information
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
- CPG 575.100 Pesticide Residues in Food and Feed - Enforcement Criteria
- 40 CFR 180-Tolerances and Exemptions for Pesticide Chemical Residues in Food
Assignments/Reports
- FDA Annual Pesticide Reports
- Summary of Feed-Through Pesticide Residues in Domestic Surveillance and Import Samples of Animal Food and Animal Food Ingredients During Fiscal Year 2000 Through 2018
Additional Information
- CFSAN pesticide program
- EPA Pesticide Ingredients
- Pesticide Analytical Manual Volume I
- Pesticide Analytical Manual Volume II Index
- Glyphosate Questions and Answers (CFSAN)
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
- FDA Per and Polyfluoroalkyl Substances (PFAS)
- USDA Chemical Residues and Contaminants
- EPA Final PFAS National Primary Drinking Water Regulation
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
- Guidance for Industry: Dioxin in Anti-Caking Agents in Animal Feed and Feed Ingredients
- Guidance for Industry: Possible Dioxin/PCB Contamination of Drug and Biological Products
Additional Information
- FSIS Announces Fiscal Year 2024 Dioxin Survey
- USDA FSIS Dioxin Monitoring Surveys
- Dioxin congener patterns in commercial catfish from the United States and the indication of mineral clays as the potential source
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
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
- LIB NO 4438 Detection of Antibiotic Residues in Distillers Grains (PDF - 228KB)
- LIB NO 4423 GC/MS method for melamine and analogues