To date, over 250 species of mould have been identified, which together produce more than 300 different mycotoxins. However, only a few of these can actually lead to contamination of feed and food: aflatoxins, Alternaria toxins, Fusarium toxins, ergot alkaloids, ochratoxins, patulin and citrinin.

Aflatoxins, for example, have carcinogenic potential and can damage genetic material. If food containing elevated levels of aflatoxins is consumed on a single occasion or over a short period, no adverse health effects are expected. Long-term consequences may include kidney damage, liver damage such as cirrhosis, and kidney and liver cancer.