Is hexane in food a cause for concern?

From everyday cooking oils to infant formula, many foods we eat rely on carefully controlled processing methods that help extract key ingredients from plants. One of the tools often used in this process is hexane – a solvent derived from petroleum that has been used for decades to extract oil from seeds efficiently and cheaply. Recently, however, hexane has come under public and political attention. A French politician has proposed a ban on its use in food production, citing concerns for public health. A newly published scientific study offers a detailed comparison of hexane and possible alternatives, helping to put the conversation into perspective.

So, what exactly is hexane? Why is it used – and what does the science say about its safety? Here’s what to keep in mind when reading the headlines.

What is hexane and why is it used in food?

Hexane is a petroleum-derived solvent that has been widely used in the food industry, particularly to extract oils from seeds such as soybeans, rapeseed, and sunflower. After the seeds are crushed, they’re mixed with hexane, which pulls the oil out of the seeds very efficiently. Afterward, the oil goes through a series of refining steps that remove almost all the hexane before the oil reaches the supermarket shelves. According to EU law, the maximum residue levels of hexane are set at 1 mg/kg of oil. That’s why you don’t find hexane as an ingredient on a food’s ingredient list – it’s not a food additive, but a technical aid in food production.

Concerns about hexane include potential health risks and its environmental impact. Hexane residues in food are generally very low, but outdated safety studies might not fully address long-term exposure effects. Hexane has been shown to harm the nervous and reproductive and endocrine systems in animal studies and workplace exposure cases.

Environmentally, hexane contributes to air pollution and smog formation due to its volatility, causing respiratory issues and eye irritation. Hexane is also derived from non-renewable fossil fuels, adding to its environmental footprint. However, hexane remains popular due to its efficiency, cost-effectiveness, and higher oil yield compared to mechanical extraction, which could potentially lead to increased crop production and deforestation.

French deputy Richard Ramos recently proposed a bill for health warnings on food products using hexane, which would suspend its use for at-risk populations and gradually move to a complete ban.

The study behind the headlines

Recently, a new study has been published comparing various solvents, including hexane, that are used to extract oils from seeds. The goal was to help understand the pros and cons of each option, and to support better decision-making.

The researchers compared a range of different solvents across many important factors, including how well they extract oils, worker safety (such as explosion risks or exposure to fumes), impact on the environment, energy needed to run the process, the quality of the final food products, whether the solvent is ready for use in real factories, and how affordable the process would be. Each solvent was given scores based on how well it performed in these different areas, and the scores were compared to see the bigger picture.

The study found that hexane is still the most efficient and economical solvent for extracting oils, which explains why it’s so widely used today. However, they also acknowledged drawbacks: hexane is made from fossil fuels, contributes to air pollution, and requires strict safety controls for workers.

Some alternatives, like 2-methyloxolane and ethyl acetate, look promising because they’re less toxic and better for the environment compared to hexane. But these alternatives aren’t yet widely used in industry, can be more expensive, and may require major changes to factory equipment and energy use. Other solvents like dichloromethane also had drawbacks: although they reduce fire risks, they’re more toxic for workers and the environment.

In conclusion, every solvent has trade-offs. The researchers suggest that any decision about replacing hexane should be based on careful, multi-criteria thinking, not just focusing on one issue (like toxicity) without considering the others.

What to keep in mind when reading the study’s conclusions?

• There is limited updated data about the quantities of hexane residues in oils.

The study acknowledges that real-world data on hexane residues in refined oils are scarce and often outdated. Most residue measurements come from a small number of studies, some of which show inconsistencies. Without a broader, more recent dataset using highly sensitive detection methods, it remains difficult to precisely quantify consumer exposure today. This limitation affects the certainty of health risk assessments based on residue levels.

• Toxicological data on hexane is outdated.

The study emphasises the need for more up-to-date evaluations on the safety of hexane used as an extraction solvent in food production. The latest safety assessment on hexane from the European Food Safety Authority (EFSA) is from 1994. The main study used to establish safety was a 90-day toxicity study on animals (done in 1989). This study looked at fairly high doses of hexane and tried to determine a level where no harmful effects were observed – called the no-observed-effect level. Based on this information, regulators at the time concluded that hexane residues in food, after normal processing and refining, didn’t pose a health risk for consumers.

However, since then science has advanced, and more updated toxicological methods are available now. EFSA is now working on a full re-assessment of hexane, with modern methods and updated data, to better understand the real risks, if any, linked to hexane residues in food.

The 1989 key study in EFSA’s assessment only lasted 90 days, which doesn’t fully reflect what happens with long-term, low-level exposure over a lifetime – the kind of exposure consumers would actually experience. At the time, the tools scientists had weren’t as good at detecting very small traces of hexane in oils. Because of that, there’s some uncertainty about how much hexane was actually left in different oils after they were processed. The current risk assessment also includes factors like vulnerable groups (infants, pregnant women), which were not thoroughly addressed in older assessments.

• Alternatives to hexane may introduce new risks or challenges.

Assessing solvents involves multiple, sometimes competing criteria – extraction efficiency, worker safety, consumer safety, environmental impact, cost, technology readiness, etc. A solvent that excels in one area may perform poorly in another. There is no one-size-fits-all answer, and conclusions depend heavily on which criteria are prioritized (e.g., consumer health vs. industrial viability vs. environmental footprint).

While alternatives like 2-methyloxolane, ethanol, or ethyl acetate offer certain advantages (e.g., lower toxicity, better environmental profiles), they also present significant trade-offs: higher energy consumption, increased process complexity, compatibility issues with existing industrial equipment, and in some cases, their own toxicity concerns. Simply switching to an alternative does not automatically guarantee safer, greener food production.

What do the authorities say?

• Hexane is authorised under current EU law for use as an extraction solvent in food production, subject to strict residue limits (1 mg/kg for oils). The European Food Safety Authority (EFSA) released a technical report in 2024, noting a need for updated exposure and residue data but not yet recommending a ban. A full mandate has been given to EFSA to reassess hexane comprehensively, with results expected soon. Until then, current safety assessments remain valid, and products using hexane continue to be considered safe under the existing regulations.