Investigating the origin of high hexane residue contamination in the general population’s blood and urine

Hexane is widely used worldwide for food extraction. Each year, about 1.2 Million tons of hexane are consumed to produce edible oils, natural extracts, plant proteins and feed materials. Without hexane extraction, the world would lose well defatted, long shelf-life feed meals which are the main protein source for conventionally raised cattle. Hexane extraction however is becoming more and more challenged. In Europe the EFSA (European Food Safety Authority) concluded in a report dated September 2024 that hexane approval for food should be reassessed due to food safety issues. In that report, EFSA proposes for the first time three different simulations of the European population exposure to hexane coming from extracted products. We compared these simulations with the predicted hexane contamination which can be deducted from 2,5-hexanedione measured in the general population urine by previous studies. This comparison shows that the contamination coming from the extracted products could only explain 50% of the measured contamination. Other studies allow to exclude a significant contamination coming from ambient air. The missing 50% contamination could come from residue in animal products contaminated by the hexane extracted feed meals. New measurements on animal matrixes allowed us to show that hexane residues pass into milk, eggs and meat.  According to a 1978, ingestion study related to marked 2-hexanone, one of the hexane metabolites, the high level of hexane exposure of the general population might also be caused by difficulties that humans have detoxifying hexane and its degradation products.