What are Mycotoxins?

While the Food and Drug Administration (FDA) has been dealing with mycotoxin contamination for years, new state regulations in California have only recently started to require that all cannabis products be tested for mycotoxins. You might not be familiar with mycotoxins, but they represent a major source of contamination for cannabis flower and other cannabis products.

What are Mycotoxins?

Mycotoxins are toxic secondary metabolite compounds produced by mold or fungi. Mold can infect cannabis flower as well as crops that go into the production of edibles and other cannabis products. Under the right conditions, mold can grow before plant harvest, during storage, or even directly on food items. Improper storage conditions create the perfect warm and humid environment for mold to flourish.

As mold grows and replicates, it naturally produces mycotoxins as metabolic byproducts. Unfortunately, many mycotoxins are relatively stable. This means they can remain chemically intact and toxic even after the harsh treatment of food processing.


Aflatoxins are a family of compounds and represent one of the most noxious classes of mycotoxins. They’re produced by molds like Aspergillus that grow in soil and on grains.

Ochratoxin A, another mycotoxin, is produced by multiple species of Aspergillus and Penicillin. This is one of the most common food-contaminating mycotoxins.

Safety Risks

Mycotoxins are known to be severely toxic to humans, especially when exposure is chronic.

High levels of aflatoxin exposure, though very rare, can lead to an acute, fatal reaction. However, chronic exposure to low doses of aflatoxins causes damage to the liver and suppresses the immune system. Aflatoxins are carcinogenic and prolonged exposure can lead to an increased risk for liver cancer. Ochratoxin A can cause kidney damage and compromise the immune system.

These risks may be more pronounced in medical cannabis consumers who have pre-existing liver or kidney damage or are undergoing chemotherapy or radiation therapy.

Regulations and Testing

The FDA requires mycotoxin testing for our food supply, but until recently, there was no mycotoxin testing requirement for cannabis. With the enactment of a new set of regulations in January 2019, all cannabis produts sold by licensed distributors in the state of California must be tested for mycotoxins. These new regulations for mycotoxins establish maximum acceptable levels for several Aflatoxin variants and Ochratoxin A.

At Encore Labs, we use Liquid Chromatography-Tandem Mass Spectroscopy to test for mycotoxins. We can detect even trace levels of mycotoxins in a wide variety of cannabis products.


Mycotoxins are a common plant and food contaminant that present unique health and safety challenges. But with high-quality cannabis testing, you can ensure that your products meet state regulations and are ready for your customers to safely consume.