Aflatoxin has long been treated as a southern problem — a perennial contaminant of corn and peanuts in hot, drought-prone states like Texas, Georgia, and Mississippi, but a rare exception in the Corn Belt states of Iowa, Illinois, and Indiana that together produce the majority of US corn. That geography is changing. Peer-reviewed climate modeling published in Environmental Research Letters projects that 89.5% of corn-growing counties across 15 states will experience increased aflatoxin contamination between 2031 and 2040 compared to the previous decade. The mechanism is straightforward: Aspergillus flavus and A. parasiticus, the fungi that produce aflatoxin, thrive under hot and dry conditions that make crops physiologically stressed and more vulnerable to fungal invasion. As those conditions become more common across the Midwest, what has historically been a regional specialty food safety problem is becoming a national one — and 2026 sits squarely on the approach slope of that transition.

Aflatoxins are secondary metabolites produced by Aspergillus fungi — not synthetic contaminants introduced through human activity, but naturally occurring compounds that are among the most potent hepatotoxins and carcinogens known to science. Aflatoxin B1 (AFB1) is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer. It is metabolized in the liver into a reactive epoxide that binds covalently to DNA, inhibiting replication and RNA synthesis, and causing mutations that underlie hepatocellular carcinoma with chronic exposure. It is also immunosuppressive, and chronic low-level exposure — through staple foods in affected regions — has been linked to stunted growth in children and increased susceptibility to infectious disease.

The economic stakes are equally serious. A comprehensive review published in 2024 estimated that aflatoxin contamination costs the global agri-food system between $6 billion and $18 billion annually through trade rejections, healthcare costs, and productivity losses. In the United States specifically, the corn industry alone faces annual losses ranging from $52 million to $1.68 billion depending on drought severity — with the worst outcomes concentrated in years that look increasingly like the new normal for the American Midwest. The 2012 drought, which caused widespread aflatoxin contamination across Iowa, Illinois, and Indiana, was treated as an anomaly. Climate projections suggest it was a preview.

The FDA has established action levels for aflatoxin in US food and feed that function as the regulatory floor for grain marketing. For human food, the action level is 20 parts per billion (ppb) total aflatoxin. For dairy cattle feed — where the critical concern is carryover of aflatoxin M1 into milk — the limit is 20 ppb in feed, corresponding to the 0.5 ppb limit for aflatoxin M1 in fluid milk. The EU imposes significantly stricter limits, with maximum levels of 4 ppb total aflatoxin for food intended for direct human consumption and 2 ppb for aflatoxin B1 alone. These tighter European standards create a real compliance burden for US exporters whose grain meets FDA action levels but fails at EU border controls — a dynamic that trade data shows has cost American agricultural exporters hundreds of millions of dollars in rejected shipments during high-contamination years.

Over 100 countries now mandate analytical safety testing for mycotoxins in grain, and many have established maximum acceptable limits for specific toxins and commodity combinations. For grain processors, food manufacturers, breweries, animal feed producers, and food safety laboratories, the regulatory compliance requirement is not optional and not static — it is a moving target that gets more demanding as scientific understanding of aflatoxin’s health effects at low concentrations improves and as trading partners tighten their import requirements in response.

Aflatoxin testing needs differ significantly by matrix and point in the supply chain. Grain at intake requires rapid screening capable of processing high sample volumes against a clear pass/fail threshold. Mid-processing and finished product testing requires quantitative precision at concentrations relevant to regulatory action levels. Dairy programs require dedicated M1 monitoring in milk to catch carryover from contaminated feed before fluid milk reaches consumers. Each application has its own sensitivity requirement, matrix complexity, and turnaround demand.

Attogene’s Total Aflatoxin ELISA Kit (SKU: EL2064-1) is a competitive immunoassay covering all four principal aflatoxin types — B1, B2, G1, and G2 — in a single 96-well format with a limit of quantitation of 1.0 µg/kg and a limit of detection of 0.3 µg/kg. This sensitivity places it well below both the FDA 20 ppb action level for human food and the EU’s 4 ppb maximum level, making it appropriate for export-compliance screening as well as domestic regulatory programs. For programs specifically requiring B1 quantification — the most toxicologically significant congener and the one targeted by EU maximum residue limits — the Aflatoxin B1 ELISA Kit (SKU: EL2064) delivers equivalent sensitivity against this single analyte. Both kits are designed for cereal grains, vegetable oils, and feed matrices, and are compatible with automated plate reader systems for high-throughput laboratory workflows.

When dairy cattle consume aflatoxin-contaminated feed, the liver converts AFB1 into its hydroxylated metabolite, aflatoxin M1, which is excreted in milk. This carryover pathway means that aflatoxin contamination in grain is not only a grain safety problem — it is a dairy safety problem. The FDA limits aflatoxin M1 in fluid milk to 0.5 ppb; the EU imposes a stricter limit of 0.05 ppb. Attogene’s Aflatoxin M1 ELISA Kit (SKU: EL2053) uses a competitive immunoassay format designed specifically for liquid dairy matrices. Dairy programs in states entering the climate risk window for higher aflatoxin contamination — increasingly including Midwest corn-producing states — should treat M1 monitoring not as a supplementary check but as a core component of their food safety plan.

Aflatoxin thrives in heat and drought. Its Fusarium counterparts — deoxynivalenol (DON, also known as vomitoxin) and T-2 toxin — follow the opposite weather pattern, proliferating in wet, cool conditions during flowering and early grain fill. A complete grain safety testing program must account for both ends of the weather spectrum, because the same climate volatility that is expanding aflatoxin risk also produces more frequent precipitation extremes that favor Fusarium infection in cereals. DON is particularly significant for brewing and distilling industries: it accumulates readily in barley and wheat, survives malting and mashing with significant persistence, and has documented effects on yeast fermentation performance and finished product quality in addition to its regulatory status as a gastrointestinal irritant and immune suppressant.

Attogene’s Deoxynivalenol (DON/Vomitoxin) ELISA Kit (SKU: EL2063) provides quantitative measurement of DON in cereals and beer, with a limit of detection of 75 µg/kg and a limit of quantitation of 250 µg/kg, covering the range relevant to both EU and FDA regulatory limits for grain and feed. The T-2 Toxin ELISA Kit extends coverage to the trichothecene T-2, which is particularly stable against heat and therefore detectable in finished baked products as well as raw grain — relevant to the growing regulatory attention on T-2 limits being formalized across EU member states and trading partners. Together, these tools allow grain safety programs to screen the full spectrum of common cereal mycotoxins from a single laboratory platform.

A comprehensive agricultural food safety program addresses mycotoxins alongside the pesticide residues that accompany intensive grain production. Atrazine — one of the most widely applied herbicides in US corn production — is among the pesticides most frequently detected in surface and groundwater in agricultural regions. The EPA MCL for atrazine in drinking water is 3 ppb, and the compound’s persistence in soil and water systems means monitoring is required not only for regulatory compliance but for community well water safety near agricultural operations.

Attogene’s Atrazine ELISA Kit (SKU: EL2056-01) provides quantitative screening of atrazine in water samples, directly applicable to agricultural watershed monitoring, source water compliance programs, and food safety screening in regions where crop production and water supply overlap. For programs requiring coverage across a broader pesticide panel — including avermectins, ivermectin, and parathion-methyl — Attogene’s Pesticide ELISA Kit Menu (SKU: EL2022-XX) offers a configurable suite of analyte-specific immunoassays against the most commonly regulated agricultural chemical residues. Browse all available food safety and agricultural contaminant testing tools at the Attogene product list, or contact the team to discuss building a contaminant screening panel matched to your grain types, supply chain position, and market regulatory requirements.

---

The FDA action level for total aflatoxin in human food is 20 ppb. For animal feed, the limits vary by species: 20 ppb for dairy cattle (due to the milk carryover concern), 100 ppb for finishing beef cattle, and 300 ppb for finishing swine and poultry. The EU imposes stricter limits of 4 ppb total aflatoxin for human food and 2 ppb for aflatoxin B1 specifically — creating an important compliance gap for US exporters whose grain meets FDA action levels but fails EU border checks. Attogene’s Total Aflatoxin ELISA Kit detects aflatoxin at a limit of quantitation of 1.0 µg/kg, providing sensitivity relevant to both regulatory frameworks.

Aflatoxin contamination typically occurs in the field when heat and drought stress make corn plants physiologically vulnerable to Aspergillus infection. The fungi produce aflatoxin as a secondary metabolite; contamination continues and can worsen in post-harvest storage if grain is stored at elevated temperature or moisture. Once present, aflatoxin cannot be reliably removed by standard grain processing — it is chemically stable, survives milling, cooking, and most industrial treatments, and is not destroyed by the temperatures used in brewing or baking. Prevention through pre-harvest conditions and early post-harvest detection is far more effective than remediation, which is why proactive testing at grain intake is the critical control point.

Aflatoxin B1 (AFB1) is the primary fungal contaminant found in grain, corn, peanuts, and other crops. Aflatoxin M1 (AFM1) is a hydroxylated metabolite that the liver of dairy cattle produces when it processes AFB1 from contaminated feed; it is then excreted in milk. AFM1 is regulated separately in fluid milk and dairy products because it represents a distinct consumer exposure pathway. The FDA limit for AFM1 in milk is 0.5 ppb; the EU limit is 0.05 ppb. Testing grain for AFB1 and testing milk for AFM1 are both necessary components of a complete aflatoxin monitoring program in dairy supply chains.

Deoxynivalenol is a Fusarium mycotoxin that accumulates in barley and wheat under wet, cool growing conditions. In brewing, DON causes a well-documented phenomenon called gushing — the sudden, uncontrolled over-foaming of beer when a bottle or can is opened — which results from DON’s interaction with hydrophobic proteins in the wort. Beyond the product quality impact, DON persists through malting, mashing, and fermentation at varying degradation rates, and finished beer has been found to contain DON at concentrations that may approach regulatory limits in some markets. Regulatory limits for DON in cereals are established by the EU (1,250 µg/kg in unprocessed cereals for human consumption) and are being actively considered by additional trading partners, making routine DON screening at grain intake a business necessity for the brewing industry.