Per- and polyfluoroalkyl substances are a vast family of synthetic, persistent chemicals. The review notes that more than 21,000 PFAS are known, and that according to the Organisation for Economic Co-operation and Development, their theoretical number in the PubChem chemistry database already exceeds seven million and is still increasing. Their unique properties, including non-stick, hydrophobic and oleophobic behaviour, surfactant activity and high resistance to thermal, biological, chemical and physical degradation, have driven their use in more than 200 applications, from metal processing and paints to textiles, cosmetics, food packaging, semiconductors, healthcare and firefighting foams.

In the workplace, workers are mainly exposed through inhalation of dust, gases and vapours, with particle inhalation documented in sectors such as textiles, firefighting and ski waxing. Ingestion of contaminated dust through hand-to-mouth transfer and skin contact when handling impregnated materials are additional routes. Recent studies indicate that certain short-chain PFAS, including perfluoropentanoic acid, perfluorobutanesulfonic acid and perfluorobutane sulfamide, could partially cross the skin barrier, up to 7 percent in vitro, whereas long-chain compounds are not directly absorbed but tend to accumulate in skin tissue. The review stresses that occupational exposure can occur at every stage of the PFAS life cycle, from synthesis to the wear and tear or disposal of products containing them, and that workers handling these substances face substantially greater risk of adverse health effects than the general population due to complex, multiple exposures and higher levels of impregnation.

On the regulatory front, the European Union has progressively restricted or banned several PFAS, including restrictions on perfluorooctanesulfonic acid since 2009, a ban on perfluorooctanoic acid since 2020, and restrictions on long-chain perfluoroalkyl carboxylic acids from C9 to C14 since 2023. A proposal for a universal restriction covering the PFAS family, supported by five Member States, is currently under assessment within the REACH regulation. In France, the manufacture, import, export and sale of cosmetics, clothing, footwear and ski waxes containing PFAS have been restricted since January 1, 2026, and from 2030 all textiles containing PFAS will be prohibited with exemptions. The review notes, however, that the French inter-ministerial plan on PFAS includes only one action specifically dedicated to workers, and that no French occupational biomonitoring data are available to date.

A central contribution of the review is its assessment of biomonitoring procedures. Liquid chromatography coupled with tandem mass spectrometry is by far the most widely used technique for PFAS quantification, particularly in serum, but such targeted approaches have so far focused only on a few congeners. The choice of biological matrix matters: because short-chain PFAS are rapidly excreted and detectable in urine, that matrix suits recent exposure, while plasma or serum are the most appropriate for assessing chronic or cumulative exposure, and serum would be the most reliable single choice. Less invasive alternatives such as dried blood spots, hair and nails are emerging as supplementary matrices. In 2023, an inventory listed only 147 PFAS for which targeted analysis methods are available, and no targeted assay methods exist for polymeric compounds. Global approaches measuring total organic fluorine and non-targeted metabolomics can screen thousands of compounds simultaneously, including unknown ones, but their qualitative and semi-quantitative nature means they must be supplemented by targeted analysis to quantify compounds of interest.

On health effects, the review finds that the most robust human evidence concerns immunotoxicity. The most commonly reported immunotoxic effect in humans is a reduced immune response to vaccination, particularly in children. A Danish study linked prenatal and postnatal exposure to various PFAS to decreases in antibodies against measles, mumps and rubella, as well as diphtheria and tetanus; a doubling of perfluorononanoic acid, perfluorohexanesulfonic acid and perfluorooctanesulfonic acid levels in child serum was associated with reductions of 9.2, 8.3 and 7.9 percent in antibodies against mumps, respectively. In adults, inhibition of the vaccine response has also been observed, particularly after influenza vaccination. Animal studies, mainly in rodents, consistently show that PFAS can disrupt innate and adaptive immune function, with suppression of humoral immunity described as one of the most robust discoveries.

Regarding carcinogenicity, the International Agency for Research on Cancer classified perfluorooctanoic acid as carcinogenic to humans (Group 1) in 2023, based on limited evidence in humans for renal-cell and testicular cancer, sufficient evidence in male and female rats, and strong mechanistic evidence involving epigenetic changes. Perfluorooctanesulfonic acid was classified as possibly carcinogenic to humans (Group 2B). Epidemiological studies have also reported associations with breast, thyroid, liver, prostate and haematological cancers, though the review emphasises that these links are often inconsistent, and a recent meta-analysis found no positive association between six PFAS and thyroid cancer. For hepatotoxicity, some PFAS are linked to altered liver enzymes and lipid metabolism, with perfluorooctanoic acid and perfluorooctanesulfonic acid associated with markers of liver injury in large population studies, and rodent studies showing hepatomegaly, hypertrophy and necrosis at higher doses.

By contrast, the review concludes that reported results on cardiovascular, thyroid, reproductive, developmental and neurotoxic effects are less conclusive. Evidence of an association between PFAS and dyslipidaemia accumulates, but a meta-analysis of two cohorts found no evidence of an association between cardiovascular disease risks and slightly elevated PFAS blood levels. On thyroid function, results are contradictory, with a National Academies of Sciences, Engineering, and Medicine report stating that the most recent cohort studies demonstrated only a weak or no association between PFAS exposure and thyroid hormone levels or subclinical hypothyroidism. For neurotoxicity, some studies link prenatal exposure to impaired cognitive and motor development, but an expert panel concluded that available evidence remained insufficient and too heterogeneous to establish a strong causal association with neurodevelopmental or autism spectrum disorders. The review also highlights that the Firefighter Collaborative Research Project, a randomised intervention study testing whether blood and plasma donation can reduce circulating PFAS burdens in firefighters, was ongoing at the time of writing, with its findings not yet published, so it provides a framework for intervention but no evidence of cardiovascular benefit.

The authors identify regrettable substitution as a persistent problem: since 2009, regulations have led to the replacement of some PFAS with others whose toxicity has not been studied, such as hexafluoropropylene oxide dimer acid (GenX) instead of perfluorooctanoic acid, and 6:2 fluorotelomer sulfonic acid instead of perfluorooctanesulfonic acid, which may be similarly or even more severely toxic. They call for developing new detection and characterisation techniques, better understanding of the environmental and biological fate of these substances, characterising the relative contributions of inhalation, ingestion and dermal absorption in occupational settings, and assessing the effects of PFAS mixtures. An interdisciplinary approach, they argue, is essential to bridge the gap between external exposure, internal impregnation and health-risk assessment, and to establish evidence-based occupational exposure limits and effective prevention strategies for the millions of workers potentially exposed.

Subject of Research: A review of PFAS exposure, biomonitoring methods and health effects in occupational settings

Article Title: Per- and polyfluoroalkyl substances in occupational settings: a review

Article References: Cambrai-Erb, A., Chalansonnet, M., Cosnier, F., Gaté, L., La Rocca, B., Mourot-Bousquenaud, M., Zerkef, R., & Grova, N. (2026). Per- and polyfluoroalkyl substances in occupational settings: a review. Environmental Chemistry Letters. https://doi.org/10.1007/s10311-026-01930-2

Image Credits: AI Generated

DOI: 10.1007/s10311-026-01930-2

Keywords: PFAS, occupational exposure, biomonitoring, immunotoxicity, hepatotoxicity, carcinogenicity, LC-MS/MS, regulation, firefighters, PFOA, PFOS, health effects