Is Industrial Processing the Real Problem With Seed Oils? | Layne Norton, Ph.D.

TL;DR

Industrial processing of seed oils is not the real problem because hexane residues are far too small to cause harm.

Key Points

• 1.Hexane is used to extract seed oils because it's a non-polar solvent with a low boiling point (69°C), allowing it to be evaporated off quickly (within ~90 minutes) at low temperatures.
• 2.Residual hexane in finished oils is 0.05–0.5 parts per million, with many products showing non-detectable levels — well below any threshold of concern.
• 3.Hexane toxicity comes from inhalation, not ingestion. Rodent studies required 5,000 mg/kg body weight for mild liver and neurotoxicity; the human-equivalent dose translates to consuming 11,340 kg of oil just for mild side effects.
• 4.Unlike LDL cholesterol, hexane does not bioaccumulate in the blood — the body clears it before it can build to harmful concentrations over time.
• 5.Oxidation during processing is also minimal; meaningful oxidation of soybean oil requires 240°C sustained for 3–5 hours, far beyond what occurs during hexane evaporation.