The moulds which produce this mycotoxin do not infect growing barley in Europe. They can develop on harvested grain, but only if it is stored at inappropriate moisture levels, and particularly if the grain temperature is high. The minimum moisture content to support fungal development is now thought to be just above 14.5%. This is a significant change from previous understanding, and means that storage practices might have to change outside the UK. In the UK, malting barley is routinely dried to about 12% moisture before storage. This is too dry to allow ochratoxin-producing moulds to flourish. The legal limits for Ochratoxin A in cereals in the EU are 5µg/kg for raw grain and 3µg/kg for processed grain (which includes malt).
Malting barleys have been monitored for Ochratoxin A content for many years. These surveys continue to show that most UK malting barleys contain no detectable Ochratoxin A.
