Deoxynivalenol (DON), sometimes called vomitoxin, is produced by several Fusarium species but most commonly in the UK by Fusarium graminearum and Fusarium culmorum, which cause fusarium headblight in wheat.  The main risk factors for DON are rain at the time when crops are flowering and at harvest time.

In the UK risk is managed by several processes.  Farmers can assess and manage the risk to their crops by following the AHDB’s risk assessment guide.  An early warning system (CropMonitor) monitors the level of fusarium infection as the crop develops and is used to assess the potential risk across the UK.

When grain is delivered to UK flour mills, millers test the levels of DON as part of their due diligence procedures.  The grain is rejected if the levels exceed the legal or contractual limit.  A monitoring project is run by the AHDB which compares levels of DON in wheat each year using confirmatory methods.  The UK is not a high risk region for DON and this is reflected in the results from the mill testing and independent monitoring of grain, which shows that levels very rarely exceed the legal limits.

The legal limits for the presence of DON in grain are as follows:

UK Legal DON Limits in Grain Intended for Human Consumption

  DON (ppb)
Unprocessed common wheat and barley 1250
Unprocessed durum wheat and oats 1750
Flour 750
Finished products 500
Infant food 200