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Why Aflatoxin M1 Limits Vary Wildly Around the World

Written by SGS Digicomply Editorial Team | Dec 19, 2025 8:59:59 AM

It started with 100,000 dead turkeys in England in 1960. What scientists discovered in that Brazilian groundnut meal would eventually reshape food safety regulations worldwide—and create one of the most contentious debates in infant nutrition today.

The culprit? Aflatoxin, a toxic compound produced by Aspergillus flavus mold. When dairy cows consume feed contaminated with aflatoxin B1, their bodies metabolize it into aflatoxin M1, which then appears in their milk—and subsequently in infant formula made from that milk.

Fast forward to today, and we have a peculiar situation: a baby formula that's perfectly legal in China might be rejected at EU borders, while products acceptable in the Gulf region could face scrutiny elsewhere. The reason? Drastically different regulatory limits for aflatoxin M1 (AFM1) in infant formula.

A complete and filterable database with global regulations —including maximum levels, analytical requirements, and product-specific rules—is available to SGS Digicomply users. Feel free to explore the Global Ingredient Monitor demo and try this tool in action.

The Numbers Game: A 20-Fold Difference

Here's where things get interesting—and concerning for manufacturers navigating global markets:

European Union: 0.025 μg/kg (25 ng/kg)

  • The world's strictest limit, established under Commission Regulation (EU) 2023/915
  • Applies to infant formula and follow-on formula ready to use
  • Based on the principle of keeping infant exposure "as low as reasonably achievable" (ALARA)

China: 0.5 μg/kg (500 ng/kg)

  • Set by GB 2761-2017, implemented in September 2017
  • Calculated for powder products
  • Twenty times higher than the EU limit

GCC Countries: 25 ng/kg (following Codex Alimentarius)

  • Most Gulf Cooperation Council members adopt Codex standards
  • Same as EU limit, though enforcement varies by country
  • Some countries lack specific regulations for infant formula

For perspective, the United States maintains a 500 ng/kg limit for milk but sets the infant formula limit at 25 ng/kg—aligning with international standards despite having a more lenient approach for general dairy products.

Austria and Switzerland go even further, restricting AFM1 in infant foods to just 10 ng/kg—less than half the EU requirement.

Why Such a Massive Gap?

The differences aren't arbitrary. They reflect different approaches to risk assessment, analytical capabilities, and agricultural realities.

The EU's Ultra-Conservative Stance

Europe's strict limit stems from several factors:

  • High analytical capabilities allowing detection at very low levels
  • The ability to source milk from well-controlled dairy operations
  • A precautionary principle that prioritizes theoretical risk over practical challenges
  • Political pressure following various food safety scandals in the 1990s and early 2000s

The EU originally set these limits in Regulation (EC) No 1881/2006, with subsequent refinements recognizing that infant formula requires even stricter controls than regular milk.

China's Pragmatic Approach

China's higher limit isn't necessarily about lax safety standards. Rather, it reflects:

  • The challenge of controlling feed quality across a massive, diverse agricultural system
  • Different risk assessment methodologies
  • A balance between food safety and food security in a country feeding 1.4 billion people

Interestingly, a 2016 study examining 1,207 raw milk samples from Chinese infant formula manufacturers found that none exceeded the Chinese limit of 62.5 ng/L (equivalent to the 500 ng/kg standard for powder when reconstituted). This suggests the limit, while higher than Europe's, may still be protective given China's dairy infrastructure.

The Real-World Challenge: What Surveys Actually Find

Here's where regulatory limits meet messy reality. Multiple studies reveal a troubling pattern: many regions struggle to meet even basic standards.

Jordan (2014-2015):

  • 85% of infant formula samples exceeded the EU limit
  • Average contamination: 120.26 ng/kg
  • Range: 16.55 to 288.68 ng/kg
  • Yet all samples met US regulations

Mexico (Monterrey):

  • 20% of samples exceeded 25 ng/kg
  • Some samples reached 450 ng/L
  • Estimated daily intake for infants: 1.56-14 ng/kg body weight/day
  • Carcinogenic risk index scored "high risk" for all evaluated age groups

Lebanon:

  • 9.5% of infant formula samples were AFM1-positive
  • Contamination range: 29.54-140.16 ng/L
  • Hazard quotient averaged 3.05 for males, 3.28 for females
  • Margin of exposure calculations indicated genotoxicity risk

The Seasonal Factor

One fascinating finding: AFM1 contamination follows seasonal patterns. Winter months show consistently higher levels, when dairy cattle rely more on stored feed rather than fresh grazing. This stored feed, if improperly managed, provides ideal conditions for Aspergillus mold growth.

A Chinese study monitoring infant formula milk sources found exactly this pattern: 46 of 56 positive samples came from winter collection periods, compared to just 10 from spring, summer, and autumn combined.

Why AFM1 Survives Everything We Throw At It

Here's the problem manufacturers face: aflatoxin M1 is remarkably stable.

Pasteurization? Doesn't touch it. Ultra-high temperature processing? Still there. The toxin survives temperatures that would destroy most biological threats, which is why controlling it requires managing the source—the cow's feed—rather than trying to remove it from finished products.

The toxin also behaves oddly in dairy processing. Because it's not very fat-soluble, it doesn't readily transfer into cream and butter but concentrates in low-fat products like yogurt and soft cheese. For infant formula manufacturers, this means every batch of milk requires testing; there's no processing step that provides an easy fix.

The Historical Context: From Turkish Turkeys to International Trade

The story of aflatoxin regulation begins with catastrophe. When those 100,000 turkeys died in 1960 from contaminated Brazilian groundnut meal, scientists scrambled to identify the cause. William Percy Blount, a British veterinary scientist, led the investigation that eventually isolated the compound from Aspergillus flavus—giving us the portmanteau "aflatoxin."

By 1963, scientists had synthesized aflatoxin B1 and understood its structure. By the 1970s, they knew it was carcinogenic. The International Agency for Research on Cancer (IARC) classified it as a Group 1 carcinogen—proven to cause cancer in humans.

The discovery of aflatoxin M1 in milk came shortly after, when researchers realized that dairy animals consuming contaminated feed excreted a hydroxylated metabolite in their milk. This metabolite, while less potent than aflatoxin B1 (roughly one-tenth as toxic), still posed significant risks—especially for infants consuming formula as their sole nutrition source.

The first regulations emerged in the late 1960s, driven largely by whatever analytical methods existed at the time. As detection capabilities improved, limits tightened. The EU's aggressive standards emerged from a combination of improved analytical chemistry, heightened public concern about food safety, and the economic ability to source ultra-clean milk.

What This Means for Food Safety Professionals

For companies operating across borders, these varying standards create real challenges:

  1. Supply Chain Complexity: Manufacturers must know not just where their milk originates, but the entire feed supply chain for the dairy herds providing that milk.

  2. Testing Requirements: Products destined for EU markets require testing sensitivity far exceeding what's needed for Chinese or US markets. This isn't just a matter of running the test longer—it often requires different analytical equipment.

  3. Seasonal Monitoring: Smart manufacturers implement increased monitoring during winter months and in regions with hot, humid climates where Aspergillus thrives.

  4. Feed Management: The only truly effective control is ensuring dairy cattle receive feed with minimal aflatoxin B1. This typically means:

    • Sourcing grains from regions with appropriate storage facilities
    • Avoiding grains stored in high-humidity conditions
    • Regular testing of feed ingredients
    • Strict vendor qualification programs

The Bottom Line

Here's the reality: a 20-fold difference in regulatory limits doesn't necessarily mean one region cares less about infant safety. It reflects different balances between:

  • Analytical capabilities
  • Agricultural infrastructure
  • Risk assessment methodologies
  • Food security considerations
  • Trade relationships

For food safety professionals, the key insight is this: compliance with local regulations doesn't equal comprehensive safety. The EU's 25 ng/kg limit represents the global gold standard—not because it's mandated everywhere, but because it's achievable with proper controls and provides the highest margin of safety.

Studies from Jordan, Lebanon, and Mexico demonstrate that many products on the market exceed these protective limits. For manufacturers, the question isn't just "Are we legal?" but "Are we safe?"

With tools like SGS Digicomply Global Ingredient Monitoring , companies can track these evolving standards in real-time, ensuring their products meet not just local requirements but the most protective standards globally. Because when it comes to infant formula, "good enough" isn't really good enough at all.

Want to ensure your products meet the most current aflatoxin limits across all markets? SGS Digicomply provides up-to-date regulatory intelligence on contaminant limits worldwide, helping you navigate complex international requirements with confidence.

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