What is the full list of the 17 PFAS tested in the 2024 3D human skin equivalent study and their individual absorption/retention percentages?
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Executive summary
The 2024 in vitro study using 3D human skin equivalents tested 17 PFAS and found most can cross or be retained by the skin, but the available reporting only gives detailed numerical absorption/retention values for a few compounds rather than a complete table of all 17 compounds and their individual percentages [1] [2]. Shorter-chain PFAS showed the highest absorbed fractions while several long-chain PFAS were largely retained in the skin rather than fully permeating across it [1] [3].
1. Study scope, dose and what was measured
Researchers exposed 3D human skin equivalent models to 17 widely used PFAS at 500 ng/cm2 in methanol for 24–36 hours and partitioned the fate of each chemical into three fractions: absorbed (permeated through the tissue), un‑absorbed (wash‑off), and retained within the skin tissue (the absorbable dose) [1] [3] [2].
2. The individual PFAS values that reporting confirms
Public summaries and press coverage repeatedly cite a handful of specific numbers: perfluoropentanoic acid (PFPeA) had the highest absorbed fraction at 58.9% and perfluorobutane sulfonate (PFBS) had 48.7% absorbed [1]. Perfluorooctanoic acid (PFOA), one of the most regulated PFAS, showed 13.5% absorption into the bloodstream with an additional 38% of the applied dose retained within the skin at the exposure examined [2] [4]. Multiple outlets also report that 15 of the 17 PFAS tested showed “substantial dermal absorption” defined as at least 5% of the exposure dose [2] [5].
3. The pattern: chain length, physicochemistry and where material accumulated
The study authors and coverage describe a clear inverse relationship between carbon chain length and the absorbed fraction for both perfluorocarboxylic acids (PFCAs; r = -0.97) and perfluorosulfonic acids (PFSAs; r = -0.99), meaning shorter-chain PFAS permeated more readily while longer chains tended to remain within the skin [1] [3]. Reporting also highlights an inverse correlation between logKOW and absorbed fraction, and notes that steady‑state flux and permeation coefficients generally decreased with increasing chain length for compounds that permeated after 36 h [1] [3].
4. What the available reporting does not provide (and why that matters)
None of the secondary reports supplied here reproduce the full table of all 17 PFAS with their individual absorbed, un‑absorbed and retained percentages for each compound; the snippets and press coverage emphasize headline values and trends rather than the complete dataset [1] [2]. Therefore a full, compound‑by‑compound list of all 17 names with their precise absorption and retention percentages cannot be reconstructed from the supplied material; the primary article (Environment International) is cited as the source to consult for the full numerical table [1] [3].
5. Balancing interpretation, caveats and competing viewpoints
Authors and media note this is the most comprehensive in vitro dermal assessment to date but emphasize limitations: 3D skin models approximate human skin yet lack some cell types and systemic physiology, experimental conditions (solvent, dose, exposure duration) affect outcomes, and translation to real‑world exposures remains uncertain [3] [6]. Regulatory and industry voices remind readers that product uses vary and that further standardized studies, human in vivo data and toxicokinetic modeling are needed before directly translating these percentages to population risk [3] [6].
6. Where to find the complete per‑compound numbers
To obtain the full list of the 17 PFAS tested and the individual absorbed/un‑absorbed/retained percentages for each compound, the Environment International article by Ragnarsdóttir et al. should be consulted directly; the ScienceDirect and PubMed records link to that primary paper, which contains the detailed tables and methods omitted from press summaries [1] [3].