Nonpolymeric Per- and Polyfluoroalkyl Substances (PFAS) and Side-Chain Fluorinated Polymers in Canadian Building Products

To understand if exterior building products are a source of perfluoroalkyl and polyfluoroalkyl substances (PFAS) to the environment, we measured PFAS in 145 samples of paints, sealers, and textiles, mostly intended for exterior use. We first developed a combined one and two-dimensional diffusion-ordered spectroscopy (1D and 2D-DOSY) fluorine nuclear magnetic resonance (19F NMR) method to characterize and quantify side-chain fluorinated polymers (SCFPs) and nonpolymeric PFAS. Results showed that 36% (22/61), 24% (13/54), and 70% (21/30) of tested paints, sealers, and textiles contained total organic fluorine (TOF) at 0.1–16.1, 0.4–2488, and 0.34–74.0 μmol/g, respectively. Paints mainly contained 6:2 fluorotelomer (FT) and aromatic-CF3 nonpolymeric PFAS, while sealers also contained 6:2 FT SCFPs and perfluorobutane sulfonyl fluoride (PBSF)-based PFAS. Textiles contained 6:2 FT, 8:2 FT, and PBSF-based PFAS indicative of SCFPs. Advanced mass spectrometry methods revealed that paints and sealers with 6:2 FT nonpolymers mainly contained 6:2 fluorotelomer phosphate mono-, di-, and triesters (6:2 mono-, di-, and triPAPs) and 6:2 FT dipyrophosphate, while textiles primarily contained n:2 fluorotelomer alcohols (n:2 FTOH, n = 6, 8) or N-methyl perfluorobutane sulfonamide alcohol (MeFBSE). Based on the PFAS found in these products and the recommendation to reapply the coatings to protect exterior/interior surfaces and the replacement of exterior textiles, these results indicate that building products likely contribute polymeric and nonpolymeric PFAS to the environment.为明确建筑外墙产品是否为全氟和多氟烷基物质（PFAS）的环境排放源，我们针对145份主要用于外墙的涂料、密封剂及纺织品样本开展了PFAS检测。我们首先开发了结合一维与二维扩散排序核磁共振波谱（1D及2D-DOSY）的氟核磁共振（¹⁹F NMR）方法，用于表征并定量侧链氟化聚合物（SCFPs）与非聚合态PFAS。检测结果显示，受试涂料、密封剂及纺织品中分别有36%（22/61）、24%（13/54）及70%（21/30）检出总有机氟（TOF），含量范围依次为0.1~16.1 μmol/g、0.4~2488 μmol/g及0.34~74.0 μmol/g。涂料中主要含有6:2氟调聚物（FT）与芳香族-CF3非聚合态PFAS；密封剂除上述成分外，还含有6:2 FT侧链氟化聚合物及基于全氟丁烷磺酰氟（PBSF）的PFAS；纺织品则含有6:2 FT、8:2 FT及表征侧链氟化聚合物的PBSF基PFAS。先进质谱方法分析结果表明，含有6:2 FT非聚合态物质的涂料与密封剂，主要成分包括6:2氟调聚物磷酸单酯、二酯及三酯（6:2 mono-、di-及triPAPs）与6:2氟调聚物二焦磷酸盐；而纺织品的主要成分为n:2氟调聚物醇（n:2 FTOH，n=6、8）或N-甲基全氟丁烷磺酰胺醇（MeFBSE）。基于此类产品中检出的PFAS，结合外墙/内墙防护涂层需定期复涂、外墙纺织品需更换的行业惯例，本研究结果表明建筑产品大概率会向环境中释放聚合态与非聚合态PFAS。