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  1. Natural Toxins in Food


Toxins found in food infected by certain molds or fungi

FDA monitors mycotoxins in food

Some foods—such as grains, dried beans, dried fruits, and coffee—are susceptible to fungus or mold that produce toxins known as mycotoxins. Only certain molds and fungi can produce mycotoxins of concern. If you eat something containing high levels of those mycotoxins, you can get sick. If you eat something from an animal that ate mycotoxins (such as milk from a cow that ate mycotoxin-infected corn), you can get sick.

As an individual consumer, you generally cannot control the presence of mycotoxins in your food. The fungi that produce mycotoxins generally grow during crop production and storage – steps in the food supply chain that the FDA regulates and monitors to ensure the food available for you to buy is not contaminated. The mycotoxins in human food that the FDA currently focuses on are aflatoxins, deoxynivalenol, fumonisins, patulin, and ochratoxin A.


Aflatoxins are mycotoxins produced by certain Aspergillus molds. Several types of aflatoxins exist, but food contamination usually involves aflatoxins B1, B2, G1, and G2 for crops and M1 for milk.

Environmental factors such as temperature, humidity, and the amount of rain affect whether mold will grow on food while it is growing, being harvested, and/or stored. The foods most susceptible to aflatoxins include peanuts, corn, tree nuts such as Brazil nuts and pistachios, and some small grains such as rice. Aflatoxin M1 is also found in milk of cows that eat aflatoxin B1 contaminated crops.

Regularly eating foods with aflatoxins can increase your risk of liver cancer, cause birth defects, and lead to kidney and immune system problems. Eating food containing a large amount of aflatoxins at one time can lead to liver failure and even death.

Because of these health risks, the FDA has published action levels for aflatoxin and regularly tests foods for the presence of aflatoxins. By using modern agricultural and processing techniques, companies can reduce the possibility of contamination in their products.


Several Fusarium molds produce deoxynivalenol (DON), also known as vomitoxin. The mold grows on wheat, corn, oats, barley, and other grains under normal weather conditions, but especially in cool, wet conditions.

Processing wheat properly can reduce the level of DON in products like flour but will not completely get rid of it. The FDA has published an advisory level for DON in finished wheat products (like flour) that humans eat. When the amount of DON in a food product is at or lower than the FDA advisory level, it does not appear to pose a danger to people who eat these food products.

DON has been found in bread, noodles, beer, popcorn, and other foods. Eating foods with high levels of DON can cause vomiting, nausea, and other symptoms.


Certain strains of the Fusarium molds produce mycotoxins called fumonisins. These molds commonly infect corn but also sometimes infect other grains like wheat.

The level of fumonisins in a corn product depends on weather conditions. High levels of this toxin occur when hot, dry weather is followed by a period of high humidity. Milling, storage, and manufacturing processes can also affect levels of contamination with fumonisins.

We know that fumonisins can cause a variety of illnesses in animals, especially to their liver and kidneys, but more research is needed to know exactly how these toxins affect humans. The FDA has published guidance levels for fumonisins.


Patulin is a mycotoxin produced by Penicillium, Aspergillus and Byssochylamys molds that grow on fruit, grains, and cheese. The best-known example is patulin in juice or cider made from apples. Good harvest and storage practices—such as removing rotten portions of fruit—can get rid of or greatly reduce patulin contamination. Fermentation also appears to destroy patulin so it is not typically found in vinegar or alcohol made from fruit susceptible to the molds.

The risk of patulin contamination increases when companies use moldy apples to make apple juice. Pasteurization won’t get rid of patulin. Drinking the contaminated apple juice can cause nausea, vomiting, and possibly damage the DNA in some body cells.

The FDA has set an action level for patulin in apple juice and apple juice products.

Ochratoxin A

Ochratoxin A is a mycotoxin produced by certain Aspergillus and Penicillium molds. It’s been found in contaminated grains, such as wheat, rye, oat, and barley, and in coffee, grapes and wine. Contamination generally occurs when these foods are not stored and/or dried properly.

We know that ochratoxin A can cause kidney damage in animals. It may possibly cause cancer in humans, but more research is needed to know exactly how this toxin affects humans.

How the FDA Monitors and Tests Mycotoxins in Foods

The FDA monitors mycotoxins in food and conducts research on how to best detect and prevent mycotoxin contamination.

Methods for Testing

The FDA has established official methods for analyzing mycotoxins, which you can find in Chapter 7, Part IV, Section II of the FDA’s Compliance Program Guidance Manual on Mycotoxins in Domestic and Imported Foods (CP 7307.001).

The FDA’s Office of Regulatory Affairs (ORA) laboratories are in the process of transitioning to a multi- mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method that has been multi-laboratory validated for the simultaneous quantification of twelve mycotoxins in food (https://www.fda.gov/media/114240/download). You can:

FDA-USDA Coordination on Aflatoxins

The FDA and the Agricultural Marketing Service in the U.S. Department of Agriculture have a Memorandum of Understanding (MOU-225-19-031) that sets each agency’s responsibilities regarding sampling and analyzing raw peanuts, Brazil nuts, and pistachio nuts for aflatoxins.

FDA Research

Information for Industry

Mycotoxins in General


Deoxynivalenol (DON)



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