How much aflatoxin is considered dangerous?

While consuming any amount of aflatoxin is potentially dangerous, it is almost impossible to completely remove all aflatoxin from foods and feed. Therefore, many organizations and countries limit the amount of aflatoxin – as total aflatoxin and/ or just a single type, usually aflatoxin B1 – that can be present in food and feed.

Based on medical studies, the U.S. has established the following minimum total aflatoxin level for food for people and animals:

Aflatoxin limits for food

Food for …Aflatoxin limit (ppb)
Human consumption20
Beef cattle300
Swine200
Breeding cattle, swine or poultry100
Immature animals20
Dairy Animals20
U.S. Department of Agriculture standards, National Grain and Feed Association, 2014

The EU has established a limit of 4 parts per billion (ppb) total aflatoxins in human food and 20 ppb of aflatoxin B1 in animal feed. Other countries have established limits that are similar to either the US or the EU.

Levels in the ppb range are extremely low amounts, comparable to one grain of rice in a 50 kg bag or one drop of water in a swimming pool. Ppb can also be expressed as ug/kg (microgram per kilogram).