PFAS (Per- and polyfluoroalkyl substances) are a large group of synthetic chemicals widely manufactured and used in industrial and consumer products globally. These compounds are commonly known as “forever chemicals” due to their extreme persistence in the environment and the human body. Their presence in water, air, and soil has raised public health concerns extending beyond ingestion and inhalation. This article investigates the emerging scientific research regarding the impact these chemicals may have on the integrity and health of human skin, covering how they interact with the skin barrier, the types of reactions reported, and practical steps to reduce personal exposure.
What Are Per- and Polyfluoroalkyl Substances
PFAS are defined by a unique chemical structure featuring a chain of carbon atoms bonded to fluorine atoms. This carbon-fluorine bond is one of the strongest in organic chemistry, providing remarkable stability and resistance to degradation by heat, water, and oil. These properties led to their use since the 1940s in non-stick coatings, waterproof fabrics, and stain-resistant materials.
The family includes thousands of different compounds, such as Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS). Because of their stable nature, once released into the environment, they do not break down naturally and can accumulate in living organisms, including humans, over time. This bioaccumulation is a primary reason for limiting exposure to these compounds.
Scientific Evidence Linking PFAS to Skin Issues
Recent toxicology studies confirm that the skin, once thought to be an impenetrable barrier, can absorb a substantial proportion of certain PFAS compounds. Research using laboratory-grown human skin models demonstrated that up to 13.5% of an applied PFOA dose could permeate the skin and reach the bloodstream. This absorption pathway indicates that dermal contact is a significant route of exposure.
The efficiency of absorption is linked to the chemical’s structure; newer, shorter-chain PFAS compounds are more readily absorbed than older, longer-chain variants. For instance, one short-chain compound demonstrated nearly 60% absorption in laboratory testing. Once absorbed, PFAS have been shown to interfere with the immune system, suppressing the antibody response in animal models.
The proposed mechanism for direct skin effects involves interference with the epidermal barrier function. Studies show that PFOA and perfluorononanoic acid (PFNA) can induce cytotoxicity in human keratinocytes, the main cells composing the outer layer of the skin. This exposure downregulates genes responsible for maintaining the skin barrier, such as filaggrin and claudin-1. Disruption of these genes weakens the skin’s defense system, making it vulnerable to external stressors and inflammation.
Common Dermatological Reactions
The observation of barrier disruption provides a biological explanation for dermatological reactions associated with PFAS exposure. Epidemiological studies link elevated levels of specific PFAS, such as PFNA, to a higher prevalence of atopic dermatitis. Atopic dermatitis, or eczema, is characterized by chronically dry, inflamed, and intensely itchy skin, aligning with the observed breakdown of the skin barrier.
Exacerbation of pre-existing skin conditions, particularly eczema, is a concern for individuals with high environmental exposure. Weakening the epidermal layer leads to chronic dryness and increased sensitivity, making the skin susceptible to irritation and allergic responses from other factors. Although PFOA may not be an irritant itself, its ability to compromise the skin’s natural defenses can indirectly cause or worsen conditions like irritant and allergic contact dermatitis.
Primary Pathways of Skin Exposure
PFAS exposure through the skin occurs primarily through direct contact with products containing the chemicals. Contaminated water is a significant source, as showering and bathing in water containing PFAS can lead to dermal absorption. The chemicals transfer from the water to the thin fluid layer on the skin surface.
Many consumer goods are designed with PFAS for water- or stain-repellent characteristics, leading to incidental skin contact. Common pathways include:
- Clothing, footwear, outdoor gear, and household items like stain-resistant carpets.
- Cosmetics and personal care products, such as waterproof mascara, foundations, and sunscreens.
- Dust found in homes, which contains PFAS shed from consumer products.
Minimizing Personal Contact
Individuals can take several steps to reduce daily PFAS exposure through the skin and environment. Since contaminated water is a source of absorption, filtering tap water used for drinking and bathing is a primary strategy. Filtration systems using activated carbon or reverse osmosis are effective for removing these compounds.
To decrease contact with treated textiles and packaging, avoid products labeled as stain-resistant, water-repellent, or grease-proof. When selecting personal care items, check ingredient labels for terms that include “fluoro” or “perfluoro,” which indicate the presence of PFAS. Improving household hygiene by regularly wet-mopping and using a vacuum cleaner equipped with a HEPA filter also helps reduce the accumulation of PFAS-laden dust.