Residual hexane in edible oil: What are the myths and facts?

Technical hexane is a key and widely authorized extraction solvent used in the production and fractionation of edible vegetable oils, fats and other foodstuffs. It is colorless, stable, inexpensive, and recyclable, and generally shows the best overall performance compared to other proposed alternative extraction solvents. Typically, technical hexane consists of a variable mixture of petroleum-derived hydrocarbons, including n-hexane and its isomers 3-methylpentane, 2-methylpentane, methylcyclopentane and cyclohexane, in addition to heptane and cyclopentane. It may also contain traces of other food contaminants, such as mineral oil saturated and aromatic hydrocarbons (MOSH/MOAH), benzene or toluene. Although it is typically evaporated and separated from the extracted oil, its use can result in residual presence in finished products, with a maximum limit set at 1 mg/kg for oils in Europe. Due to the inconsistency in its composition and impurities, and the outdated toxicological assessment, the European Food Safety Authority (EFSA) has recently called for a re-evaluation of the safety of technical hexane as an extraction solvent under current safety standards.

While awaiting the conclusions of this reassessment, this communication will bring clarity to the technical, processing, analytical, and regulatory aspects of this topic. We will explore and debunk common myths and present factual information surrounding the use of technical hexane in the edible oil industry. We will discuss its technical performance, and the implications of transitioning to alternative solvents for industrial processes and products, for instance its impact on energy consumption. We will critically review the recent advancements and limitations of the analytical methodologies for identifying and quantifying typical residual hexane compounds in oils and fats at trace levels. Additionally, we will examine the current regulatory landscape in Europe, and share recently collected data from multiple products.