Hexane in Food: When Processing Chemistry Meets Public Health

Hexane is one of the most widely used extraction solvents in the global food system. Derived from petroleum, it plays a central role in efficiently extracting vegetable oils from crops such as soy, sunflower, rapeseed, and corn. The same process produces protein-rich oilseed meals that are widely used in animal feed. From a technological perspective, hexane is effective, inexpensive, and well understood. From a toxicological and regulatory perspective, however, it is increasingly under scrutiny.

Curl of butter on a butter knife resting on a dark surface.

In the European Union, “technical hexane” is authorized as a food extraction solvent under Directive 2009/32/EC. Its last full safety assessment by the EU’s Scientific Committee on Food dates back to 1996. In 2024, the European Food Safety Authority (EFSA) concluded that this assessment is no longer sufficient and formally called for a re-evaluation. The reasons are scientific rather than sensational: technical hexane is not a single pure compound, its impurities are poorly specified, human absorption of n-hexane is well documented, and exposure—particularly for infants and young children—may have been underestimated under current regulatory assumptions.

At the same time, public attention has intensified. Investigations commissioned by Greenpeace reported detectable hexane residues in a wide range of everyday foods, including vegetable oils, butter, milk, infant formula, and poultry. While the measured levels generally fall within current legal limits, these findings highlight a critical gap between regulatory compliance and public expectations of food safety and transparency. Processing aids like hexane are not listed on labels, even though trace residues may remain in final products.

From a scientific standpoint, the debate raises several important questions. How robust are existing toxicological datasets for chronic, low-level exposure? Do current analytical methods sufficiently characterize impurities and residues across complex food matrices? And should efficiency-driven processing choices be reconsidered when safer—though potentially less economical—alternatives exist?

EFSA’s conclusion is cautious but clear: there is no immediate acute health concern, but the available evidence is insufficient to confidently assess long-term risks. As new toxicological data emerge and analytical capabilities improve, hexane has become a case study in how legacy food technologies can outpace the science and regulation designed to govern them. The outcome of the ongoing re-evaluation may shape not only future solvent use, but also broader expectations around transparency, precaution, and trust in the food system.

Global inconsistencies in safety standards

Hexane regulation varies widely across jurisdictions. European limits are among the most conservative, yet they rely heavily on industry-generated data. In other regions, allowable residue levels are significantly higher, and in some cases, hexane use in food and feed is largely unrestricted. This variability complicates global risk assessment and raises questions about harmonization and scientific consistency in food safety governance.

Beyond compliance: Rethinking food processing choices

The ongoing re-evaluation of hexane illustrates a broader challenge in food science: technologies adopted for efficiency and cost-effectiveness may persist long after their safety assumptions become outdated. The issue is not whether hexane poses an immediate public health crisis—EFSA has explicitly stated that it does not—but whether current scientific evidence is sufficient to justify its continued widespread use without further scrutiny.

Advances in analytical chemistry now allow more sensitive detection of residues and impurities, while modern toxicology places greater emphasis on long-term, low-dose effects. At the same time, alternative extraction technologies, though less efficient, are becoming more viable as sustainability and safety considerations gain weight.

What are the best methods for detection?

Detection options

HS-GC-FID: robust, sensitive for hydrocarbons, widely used for routine control (often aligned with “official” oil methods such as AOCS workflows referenced in the literature).
HS-GC-MS: adds spectral ID confirmation (useful when there are interferences or you want stronger identity evidence).

Quantification

Prefer internal standard calibration (often a similar volatile hydrocarbon not expected in the sample) and matrix-matched calibration where feasible.

Conclusions

EFSA concluded that there is a need to re-evaluate the safety of technical hexane used as an extraction solvent in the production of foodstuffs and food ingredients. A key aspect of this re-evaluation concerns the accurate characterization and quantification of hexane residues and related hydrocarbons, where gas chromatography (GC) plays a central role. Robust GC-based analytical methods are essential to reliably determine residual solvent levels, distinguish between different hexane isomers and impurities, and ensure compliance with regulatory limits.

Advances in GC methodology, including improved separation, sensitivity, and detection capabilities, can significantly reduce analytical uncertainty and support more precise exposure assessments. High-quality GC data are therefore critical for refining dietary exposure estimates, identifying potential sources of variability, and supporting a science-based risk assessment. Strengthening analytical controls through validated GC methods will be an important component of addressing EFSA’s safety concerns and ensuring continued consumer protection.

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