Mycotoxin Survey in US corn: November 2018 update

This preliminary report is an update from incoming samples of the 2018 corn harvest from August to November. 


6 major mycotoxins
  • 177 samples tested
  • 23 States
  • Corn (73%), corn silage and fresh corn chops (18%), and corn byproducts (10%)
  • Mycotoxins tested include: Alfatoxin (Afla), Type-B Trichothecenes (B-Trich), Fumonisins (FUM), Zearalenone (ZEN), Ochratoxin (OTA), and Type-A Trichothecenes (A-Trich)
  • Testing done by independent laboratories using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)


  • 93% positive for at least one mycotoxin compared to 91% in 2017
  • Increase in co-occurrence with 58% of samples containing more than one mycotoxin compared to 48% in 2017
  • Jump of Afla prevalence to 10%, higher than the previous three years (2015 to 2017).
  • Prevalence of ZEN holds steady at 34%, similar to 2017.
  • B-Trich prevalence decreases across national sample pool to 64% from 79% in 2017.
  • B-Trich has higher prevalence in the Midwestern states compared to Southern states. 
  • Prevalence of FUM at 70%, increasing from 43% in 2017.

Contamination Levels

Contamination Levels
  • Average contamination levels of Afla are higher than previous years at 147 ppb.
  • Average contamination levels thus far of ZEN and B-Trich are similar to 2017.
  • The current sample pool has a significant increase in average contamination level of FUM at 3,375 ppb, compared to 2,166 ppb in 2017.

Distribution of Positive Samples

Distribution of Positive Samples
  • 61% of positive Afla samples over 20 ppb
  • 60% of ZEN samples over 100 ppb
  • 29% of positive B-Trich Samples over 900 ppb
  • 41% of positive FUM samples over 2000 ppb

Prevalence in Major Corn Producing States

(KS & NE not included due to single sample)

  • Prevalence of B-Trich is skewed to Midwestern states, with major corn producing states such as IA, MN, and OH having over 90% of samples testing positive for B-Trich.
  • Fumonisin is dominant in MO, IL, and IN, with 90% and higher prevalence.
  • Zearalenone is prominent in IA, WI, MN, and OH, with prevalence of 50% and higher.

Risk Levels

Risk Levels
  • Aflatoxin levels above 20 ppb in 9 states
  • Contamination of samples with B-Trich above 900 ppb in 8 states
  • Contamination of samples with FUM above 2000 ppb in 12 states
  • Zearalenone levels exceeding 100 ppb were detected in samples from 8 states. 

*Data for OTA and A-Trich are not included due to small number of positive samples


BIOMIN America and the authors had no influence on the sampling process of the investigated samples. Therefore, the contamination levels found in the samples do not necessarily reflect the actual contamination level of these regions/commodities. However, the samples provide more insight into the range and levels of mycotoxins which can be found in diverse commodities of various regions.