A fluorinated active ingredient (perfluorohexyloctane) used in some over-the-counter eye drops can alter liver cells and be partially converted into a PFAS-like compound. This is shown by a new study by Örebro University, which has been published in Environment International.

The investigation was triggered by questions from a journalist about the safety of eye drops. The researchers led by Prof. Tuulia Hyötyläinen, an expert in chemistry, and PD Dr. Andi Alijagic, head of the experiments, investigated the substance, which is structurally similar to PFAS, but was previously considered biologically inactive.

However, the analysis revealed global changes in the metabolism of human liver cells under long-term, low-dose exposure – a scenario that corresponds to repeated use. In addition, it has been shown that perfluorohexyloctane is partially converted into a PFAS-like substance (perfluorohexyloctanoic acid) in the cells. This refutes the assumption that the substance remains unchanged in the body.

Although the results are not directly applicable to health effects in humans, they do suggest a risk in long-term exposure. The researchers call for further long-term studies in vivo and a more precise regulatory assessment of fluorinated compounds in medical and hygiene products. It is noteworthy that similar substances are prohibited in ski wax, but not in eye drops.

The study highlights the need to investigate the safety of fluorinated chemicals in everyday products more closely in order to minimize long-term health risks.

Original Paper:

Alijagic A. et al.: Metabolic effects and biotransformation of perfluorohexyloctane in human hepatocytes. Environment International, 2026. DOI: 10.1016/j.envint.2026.070X

Editor: X-Press Journalistenbüro GbR

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