PFNA

PFNA contamination of U.S. drinking water has a distinctive geographic fingerprint dominated by a single industrial source: Solvay Specialty Polymers' fluoropolymer manufacturing plant at West Deptford / Paulsboro, New Jersey (formerly operated by Arkema and Atofina). PFNA served as a polymerization aid at the plant from the mid-1980s onward, and direct discharge plus atmospheric deposition produced an extensive groundwater plume across Gloucester County and surrounding South Jersey communities — the UCMR 5 detection list reflects this directly, with the National Park Water Department (15.3 ppt), Brooklawn Water Department (12.5 ppt, 20 of 20 tests positive), Westville Water Department (12.1 ppt, 23 of 23 tests), Gloucester City Water Department (11.3 ppt), and East Greenwich Township (13.6 ppt) forming a tight cluster of utilities all exceeding the federal 10 ppt MCL. New Jersey's response to the plume included a 2018 state-level PFNA MCL of 13 ppt that pre-dated federal action and made PFNA one of the most-studied PFCAs at the state regulatory level. Secondary sources include AFFF release at military installations and civilian airports, biotransformation of 8:2 fluorotelomer precursors used in stain- and grease-resistant coatings on textiles, paper, and food packaging, and isolated small-utility detections at remote sites (Goldens Bridge, NY at 59.8 ppt and Sunny Gables, ME at 55.1 ppt likely reflect localized AFFF or industrial point sources).

PFNA shares the long-chain PFCA toxicological profile of PFOA and PFDA: published animal and epidemiological studies link PFNA exposure to reduced birth weight and altered immune development, hepatotoxicity, dyslipidemia (elevated cholesterol), thyroid effects, and reduced antibody response to childhood vaccines. EPA's inclusion of PFNA in the NPDWR Hazard Index mixture (alongside PFHxS, HFPO-DA, and PFBS) reflects the assumption that the four short-and-medium-chain PFAS interact additively in mixture toxicology. PFNA has not been formally classified as a carcinogen by IARC or NTP, which is why the federal MCLG is set at 10 ppt rather than zero — the MCLG-of-zero approach EPA used for PFOA and PFOS reflects their IARC Group 1 cancer classifications. PFNA bioaccumulates: median human serum elimination half-life is approximately 2.5 years, shorter than PFOA (~3 years) but much longer than the short-chain PFCAs (PFBA, PFHxA, PFHpA, ~30-70 days). Detectable PFNA appears in essentially 100% of U.S. adults sampled by NHANES, reflecting both the historical Solvay-era production and downstream consumer-product exposure routes.

PFNA responds well to the standard long-chain PFAS treatment train: granular activated carbon (GAC), anion exchange resin, and high-pressure membranes (reverse osmosis, nanofiltration). The 9-carbon perfluorinated tail provides strong hydrophobic adsorption onto GAC — PFNA breakthrough on GAC occurs later than PFOA (8C) and at loadings comparable to PFOS, making it one of the easier long-chain PFCAs to remove cost-effectively. Anion exchange resin and high-pressure membranes are also highly effective. Conventional treatment processes — coagulation, sand filtration, disinfection, UV, and ozonation — do not remove PFNA. Boiling concentrates rather than removes it. NSF/ANSI 53 and NSF P473 certify point-of-use filters for general PFAS reduction; NSF/ANSI 58 covers RO systems. Utilities targeting the 10 ppt federal MCL with GAC, AIX, or RO will simultaneously reduce PFOA, PFDA, and the other long-chain PFCAs that share treatment behavior.