Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals found in numerous everyday products due to their resistance to water, oil, and stains. Amidst the frequent scandals in the international press regarding PFAS pollution, increasing studies are attempting to evaluate how these “forever chemicals” penetrate our bodies. While ingestion was previously considered the main route of contamination, numerous studies now show that PFAS can also be absorbed through the skin.

Early Indications as early as 2012

In an initial study conducted by an American team in 2012, scientists analyzed the possible skin absorption of a type of PFAS, perfluorooctanoic acid (PFOA), used notably in non-stick cookware. They confirmed that the more the skin was exposed to PFOA, the higher the concentration of PFOA in the blood. Their pioneering results already indicated a possible entry route for PFAS into the body through the skin.

In 2022, tests ordered by the German Federal Institute for Risk Assessment (BFR), an independent body linked to the Ministry of Agriculture and Food, confirmed this hypothesis. The tests involved applying sunscreen containing a small amount of PFOA on a volunteer’s skin. In the weeks that followed, an increasing amount of PFOA was found in their blood, peaking after three weeks, after which the PFOA concentration began to decrease.

A New Study Reinforces These Conclusions

In a 2024 study highlighted by Phys.org, scientists from the University of Birmingham, England, used human skin models to study the absorption rates of 17 different PFAS. The research, led by Prof. Oddný Ragnarsdóttir, confirmed three major findings:

1. Long-Chain PFAS: Long-chain carbon PFAS (the larger molecules) are less likely to penetrate the skin compared to their short-chain counterparts. Perfluoropentanoic acid (PFPeA), used as an additive in stain-resistant paints, showed absorption rates four times higher than PFOA, which has a longer carbon chain.
2. Absorption Rates: Of the 17 PFAS tested, 15 were absorbed through the skin: at least 5% of the cutaneous exposure dose penetrated through various skin layers to end up in the blood. The absorption into the bloodstream of the most monitored PFAS (PFOA) was even 13.5%.
3. Skin Reservoir: A significant portion of the cutaneous dose remained in the skin, acting as a reservoir for future contamination. For PFOA, 38% of the applied dose was retained in the skin for potential longer-term absorption into the bloodstream.

PFAS in Cosmetics

These conclusions are worrying, especially now that it is established that PFAS are commonly used ingredients in cosmetics and hygiene products we use daily. While PFOA has been banned by the European Community since 2020, other PFAS are still widely used in nail polish, shampoo, mascara, and foundation.

A recent article by the Environmental Working Group (EWG), highlighting research on over 231 cosmetic products from more than 50 brands, revealed that more than half of them contained PFAS in varying amounts. EWG also provides a free tool to check if the products you use contain harmful chemicals, including PFAS. This initiative echoes the French application Yuka’s goal, which aims for the same transparency regarding dangerous synthetic ingredients.

Children and Pregnant Women at High Risk

Exposure to PFAS can lead to a myriad of health problems, particularly for unborn children, developing children, and immunocompromised individuals. Autism, obesity, developmental disorders, heart diseases—numerous ongoing studies attribute a key role to PFAS in the onset or explosion of certain pathologies in our society.

The skin, being the largest organ of the body, offers a significant surface for potential exposure, especially with the frequent use of personal care products containing these chemicals. With the increasing use of makeup and care products at a younger age due to relentless marketing efforts by major groups, this dermal contamination should prompt us to remain vigilant.

Reducing Your PFAS Exposure

Here are some practical tips to reduce, or even minimize, your personal and your children’s exposure to PFAS:

1. Check Product Labels: Look for PFAS or fluorinated chemicals in product ingredient lists. Here is an initial blacklist, established thanks to the CosmeBIO site:
   • PTFE
   • PERFLUORODECALIN
   • PERFLUORONONYL DIMETHICONE
   • POLYPERFLUOROMETHYLISOPROPYL ETHER
   • METHYL PERFLUOROISOBUTYL ETHER
   • PERFLUOROHEXYLETHYL TRIETHOXYSILANE
   • PERFLUOROHEXANE
   • POLYPERFLUOROETHOXYMETHOXY DIFLUOROETHYL PEG PHOSPHATE
2. Opt for PFAS-Free Products: Choose personal care and cosmetic products from brands that explicitly state they are PFAS-free.
3. Stay Informed!

To this end, we can only recommend regularly reading our blog infopfas.com. Stay connected and don’t miss our upcoming articles on PFAS!

Sources:

1. Dermal penetration potential of perfluorooctanoic acid (PFOA) in human and mouse skin, Pubmed
2. Immunotoxicity and allergenic potential induced by topical application of perfluorooctanoic acid (PFOA) in a murine model, ScienceDirect
3. Body can absorb fluorine-containing chemical PFOA through the skin, BFR
4. New study confirms forever chemicals are absorbed through human skin, Phys.org
5. Study: Toxic ‘forever chemicals’ widespread across many cosmetics categories, EWG
6. Fluorinated Compounds in North American Cosmetics, ACS Publications
7. Your guide to safer personal care products, EWG
8. What are PFAS in cosmetics and why should they be avoided?, CosmeBIO
9. What is PFOA and why is it banned in Europe?, VERIVE

*Image by Racool_studio on Freepik