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

Nonpolymeric Perand Polyfluoroalkyl Substances (PFAS) and SideChain Fluorinated Polymers in Canadian Building Products Min Liu, Chunjie Xia, Hui Peng, Elizaveta Zvereva, Darcy C. Burns, Justine Fontaine, Arlene Blum, Ariana Z. Spentzos, Zhanyun Wang, Graham F. Peaslee, Sébastien Sauvé, Marta Venier, and Miriam L. Diamond* Cite This: Environ. Sci. Technol. 2025, 59, 20642−20652 Read Online ACCESS Metrics & More Article Recommendations * sı Supporting Information ABSTRACT: 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 PBSFbased 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. KEYWORDS: Perand polyfluoroalkyl substances (PFAS), building products, paints, sealers, textiles, fluorine nuclear magnetic resonance spectroscopy (19F NMR), side-chain fluorinated polymers (SCFPs) 1. INTRODUCTION Perand polyfluoroalkyl substances (PFAS) are a class of highly persistent, anthropogenic compounds, consisting of over 14,000 individual compounds with diverse structures, and with some exhibiting well-demonstrated toxicity. 1,2 The broad range of physical-chemical properties such as thermal and chemical stability as well as surface-tension reducing properties has led to their ubituious use in a large variety of industrial, commercial, and domestic products, including aqueous filmforming foams (AFFF), cleaning products, building products, cosmetics and personal care products, and many others. 3 In turn, the widespread use of many PFAS has resulted in their ubiquitous presence in the environment (e.g., soil, biosolid, surface water), biota (e.g., fish, mammals), and humans, 4 causing adverse ecosystem and human health effects. 5 Identifying product categories that could contribute to these exposures is necessary for delineating major PFAS sources and prioritizing product categories for control measures. Paints, sealers, and textiles are building products that can contain PFAS (Table S1a,b) with a high likelihood of release because of the large surface area and/or frequent reapplication or replacement indicative of losses. PFAS can be added to paints and sealers as leveling, wetting, and antiblocking agents to enhance glossiness, reduce peeling, provide stain resistance, and improve spreadability, 6 while they are impregnated into textiles to impart water and oil repellency. 7−9 The global market for paints and other coatings is large, worth $190 billion USD in 2022 and projected to grow to $224 billion USD by 2027. 10 The increasing market demand and the changing PFAS composition due to restrictions and regulations 11,12 warrant investigation into building products currently available on the market. PFAS consist of nonpolymeric and polymeric forms, with the latter including fluoropolymers, perfluoropolyethers, and Received: May 25, 2025 Revised: July 29, 2025 Accepted: July 30, 2025 Published: September 17, 2025 Articlepubs.acs.org/est © 2025 The Authors. Published by American Chemical Society 20642 https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 This article is licensed under CC-BY-NC-ND 4.0 Downloaded via 86.129.249.125 on November 8, 2025 at 14:32:34 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles. side-chain fluorinated polymers (SCFPs). SCFPs deserve attention due to their large production volume and manifold uses, as well as their propensity to degrade into persistent nonpolymeric PFAS (e.g., perfluoroalkyl acids (PFAAs)). 13,14 Previous studies on PFAS in building products and textiles (mostly clothing 15 and industrial and medical textiles 16,17 ) primarily focused on nonpolymeric PFAS as summarized in Table S1. 16,18−20 However, less is known about the uses of polymeric PFAS, especially SCFPs, as well as nonpolymeric, nonvolatile zwitterionic, and cationic PFAS and volatile neutral PFAS in these products. Multiple analytical methods have been used to investigate nonpolymeric PFAS and total fluorine (TF) analysis in consumer products, each with advantages and limitations (Table S2). Several methods have been used for identifying SCFPs, namely matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), 21 pyrolysis-gas chromatography−mass spectrometry (py-GC/ MS), 22 and the combined use of a total oxidizable precursor (TOP) assay and combustion ion chromatography (CIC). 17 The use of 19F-NMR for characterizing SCFPs has not been reported, to the best of our knowledge. The goal of this study was to investigate the use and composition of nonpolymeric and polymeric PFAS in 145 samples of building products, namely, paints, sealers, and textiles purchased in Canada. This information is a necessary step toward assessing whether PFAS in these building products could be a substantial source of PFAS to the surrounding environment. To achieve this, we first developed a combined 1D and 2D DOSY 19F NMR method to quantify TOF and CnF2n+1 unit concentrations, to uncover the perfluoroalkyl chain length (e.g., C4, C6, C8) and chemistry of various PFAS, and to distinguish nonpolymeric PFAS and SCFPs. Targeted, suspect, and nontargeted analysis by liquid chromatographyhigh resolution mass spectrometry (LC-HRMS), targeted analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS), and targeted analysis by gas chromatography− mass spectrometry (GC-MS) were then used to determine the identity of the dominant or residual nonpolymeric PFAS (workflow shown in Figure S1a). 2. MATERIALS AND METHODS 2.1. Product Information, Chemicals, and Materials. We tested 145 products, including 144 Canadian products covering 61 paints, 53 sealers (including liquid sealers and caulks), and 30 textiles obtained as free samples or purchased from major retailers and brand outlets in the Greater Toronto Area, Canada from July 2022 to March 2023. We also tested 1 US sealer (liquid) that was purchased online from a US company in February 2023. See Table S3a-c for product information. Two Canadian sealers were labeled as containing fluorinated acrylic alkylamino copolymers (Table S3b), while all other Canadian products did not indicate any fluorinated ingredients on their labels. The US sealer was labeled as fluorinated but did not disclose the identity of the fluorinated constituents (Table S3b). Certified standards of 43 nonvolatile PFAS and 13 volatile PFAS, as well as surrogate and injection standards (Table S4af), were obtained from several suppliers. Further details on the chemicals and reagents are provided in the SI (Text S2, Table S4a-f, and Figure S2). 2.2. Sample Preparation and Analysis. For 19F NMR analysis, fluoropolymer standard solutions (e.g., polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP)) were prepared by dissolving the solid standard in 80% DMSO/20% acetone at 100−120 °C, while nonpolymeric PFAS standard solutions were prepared by dissolving the solid standards directly in methanol at room temperature. All the paints (n = 61) and sealers (n = 54) were prepared using a simple extraction method, which consisted of adding methanol, shaking (1 min) and vortexing (1 min), ultrasonication (for some viscous paints or caulking sealers only, 10 min), and centrifugation (16000 g for 10 min) at room temperature. 19 Two sealers identified as containing SCFPs with 19F NMR were also treated using a hydrolysis protocol, 23,24 which involved the addition of methanol with sodium hydroxide, vortexing, hydrolysis reaction (60 °C for 16 h), 23,24 cooling, and centrifugation. All the textiles (n = 30) were prepared by both simple extraction (methanol with 0.1% NH4OH) and hydrolysis treatment methods, 23−25 as described above. The 19F NMR analysis was conducted by using an Agilent 600 MHz DD2 NMR Spectrometer equipped with a 5 mm triple resonance HFX tuned to 564.317 MHz for 19F excitation. Full details of the sample preparation and the 1D and 2D DOSY 19F NMR methods are provided in Text S3, Table S5, and Figure S4a,b. For LC-HRMS analysis, all paints (n = 22) and sealers (n = 13) with TOF > instrument detection limit (IDL), selected paints (n = 11) and sealers (n = 5) with TOF < IDL, and all textiles (n = 30) were prepared using similar procedures as for 19F NMR with the following minor modifications. For simple extraction, paints, sealers, and textiles were spiked with surrogate standards before equilibration and/or extraction, with injection standards added to the filtered extracts or supernatants immediately before LC-HRMS analysis. For the hydrolysis treatment, the textiles were spiked with surrogate standards before hydrolysis, and an aliquot of the supernatants was neutralized with formic acid, passed through a 0.22 μm PES syringe filter, and spiked with injection standards immediately before LC-HRMS analysis. Full details of the sample preparation are provided in Texts S4 and S5. The LC-HRMS analysis was done on a Vanquish ultrahighperformance liquid chromatography (UHPLC) system coupled to a Q Exactive high-resolution mass spectrometer (Thermo Fisher Scientific), with data collected under both negative and positive electrospray ionization (ESIand ESI+) modes in an m/zrange 150−1000 (Table S6a,b). Targeted analysis was performed to quantify 43 PFAS with available standards (Table S4a,c and Figure S2), while suspect screening and nontargeted analysis (details in Texts S6 and S11) were used to identify other PFAS for which authentic standards were unavailable. 26,27 Selected paint/sealer/textile extracts were also analyzed under t-MS2(targeted MS/MS) modes (normalized collision energy, NCE = 20−70%) for elucidating the structure of qualitatively identified products, for which the confidence levels were assigned, following the methods of Schymanski et al. and Charbonnet et al. 28,29 The same paints/ sealers/textiles prepared for LC-HRMS were run on an LCMS/MS (Agilent 1290 Infinity II UPLC 6470 QQQ-MS) instrument for 6:2 polyfluoroalkyl phosphate triester (6:2 triPAP) quantification. Full details of the LC-HRMS and LCMS/MS methods are provided in Text S5 and Tables S6a-c, S7a-c, S8a,b, and 9a,b. GC-MS analysis was performed on the same paints and sealers run for LC-HRMS analysis, following the simple Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20643 extraction procedure. 19 Briefly, following methanol and surrogate standards addition, vortexing, shaking, and centrifugation, the supernatants were passed through methanol-rinsed strong anion exchange (SAX) solid phase extraction (SPE) cartridges (200 mg, 3 mL, Phenomenex, Torrance, CA) to remove PAPs that could thermally degrade at the GC inlet to form fluorotelomer alcohols (FTOHs). 19 All the textiles (n = 30) were prepared by both simple extraction and hydrolysis treatment methods as previously reported for GC-MS analysis. 23,24,30 The paints/sealers/textile extracts were spiked with internal standards immediately before GC-MS analysis. The GC-MS, operating in positive chemical ionization mode (Agilent 7890 GC−5977B PCI MS), was used to measure volatile PFAS, i.e., perfluoroalkane sulfonamido ethanol (FASEs), FTOHs, parachlorobenzotrifluoride (PCBTF), and FT acrylates and methacrylates (FTACs and FTMACs). Further details on the sample preparation and GC-MS analysis methods are provided in the SI (Text S7, Tables S6d and S10). 2.3. Quality Assurance/Quality Control. After running the calibration curve, continued calibration verification standards were inserted every 10−15 samples during the LCHRMS/GC-MS batch sequences. As shown in Table S11, the continued calibration verification standards (n = 5) showed good accuracy (82.4−129%), that fell within the 70−130% acceptance criterion set by the US EPA method 1633, 31 and low to medium intraand interday precision (0.1−36.8%). As an additional control of precision, selected samples were prepared in duplicate for instrument analysis. The low deviations in TOF and PFAS concentrations of the duplicate samples (<20%, Table S12a-c) verified the repeatability and accuracy of the sample preparation and 19F NMR/LC-HRMS/ GC-MS analysis methods. Method blanks prepared in the same way as the products and solvent blanks were also run by 19F NMR, LC-HRMS, and GC-MS, showing nondetectable or trace levels of PFAS or TOF (Tables S9a,b and S10). See Text S8 for further details. 2.4. Data Analysis. Data analysis was done by using OriginLab software (Northampton, MA, USA). For the fluorine mass balance, PFAS concentrations were converted to fluorine equivalent concentrations. 32 The Kruskal−Wallis ANOVA test was used to compare the differences between the products. p≤0.01 represented a highly statistically significant difference, and p≤0.05 represented a statistically significant difference. To close the fluorine mass balance of the tested products, the TOF determined by 1D 19F NMR was compared to the sum of fluorine equivalents from each PFAS identified by LCHRMS and LC-MS/MS (targeted, suspect screening, and nontargeted analysis by LC-HRMS and targeted analysis by LC-MS/MS) and GC-MS (targeted analysis). 3. RESULTS AND DISCUSSION 3.1. Development of a Solution State 19F-NMR Method for Nonpolymeric PFAS, SCFPs, and Fluoropolymer Analysis. We developed a combined 1D and 2D-DOSY 19F NMR method with validation using 11 nonpolymeric PFAS standards, two sealers labeled as containing a fluorinated polymer, and 9 fluoropolymer standards (workflow shown in Figure S1b); the results are shown in Figures 1,S5, S6, and S7 and Tables S5 and S13. Consistent with previous work, 19,33−36 our 1D 19F NMR method could quantify the TF, TOF, and inorganic fluoride (IF) concentrations, with the instrument limit of detection (IDL) of 2.7−3.2 μmol F/L, equivalent to 0.073−0.087 μmol F/g ww in paints/sealers and 0.014−0.016 mmol F/m2in textiles. It was also able to differentiate PFAS with different perfluoroalkyl chain lengths (e.g., C4, C6, C8) based on the number of peaks at both the CF3and CF2 regions 33−36 and identify different types of PFAS (e.g., n:2 fluorotelomers such as 4:2 FTOH, perfluoroalkane sulfonyl fluoride (PASF)-based compounds such as MeFBSE) based on their distinct chemical shifts of the neighboring CF2units connected with the nonfluorinated head groups (Figure S5a, Table S13a). 34,35,37 At the same time, our combined method has the following advantages compared with previous 19F NMR methods. First, 1D 19F NMR could determine the dominant chain length of PFAS, thus enabling quantification of SCFPs or nonpolymeric PFAS in units of mass of CnF2n+1 per gram of a sample, as opposed to fluorine equivalents, supporting the estimation of the quantity of PFAA degradation products with specific perfluoroalkyl chain lengths. Second, 2D DOSY 19F NMR could determine the diffusion coefficients of PFAS compoFigure 1. 1Dand 2D DOSY 19F-NMR spectra showing aromatic-CF3nonpolymers in sealer I-006 (a, e), 6:2 FT nonpolymers in sealer B-001 (b, f), 6:2 FT SCFPs in sealer L-002 (c, g), and 6:2 FT nonpolymers (converted from 6:2 FT SCFPs) in sealer L-002 after hydrolysis (d, h). A logarithmic scale was used for the diffusion coefficients D on vertical coordinates of (e-h), log D value of −9 means D = 10−9m2/s. Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20644 nents in a sample (Figure S6a-h, Table S13b), which can be used to estimate molecular weights (MWs) using the Stokes− Einstein Gierer-Wirtz Estimation (SEGWE) method, 38 thus enabling us to distinguish between nonpolymeric or polymeric PFAS. Specifically, the diffusion coefficients (D) of nonpolymeric PFAS standards (Log D: −9.3 to −8.7[m2/s]) gave estimated MWs of 62−1105 g/mol, which were slightly different from their theoretical MWs (accuracy: 33−140%, details in Table S13b), while the estimated MWs indicated the nonpolymeric PFAS in these standards. Unfortunately, the lack of available commercial SCFP standards prevented the validation of this combined method. However, two sealers labeled as containing a fluorinated polymer enabled us to fingerprint the 1D and 2D DOSY 19F NMR patterns of 6:2 FT SCFPs (see Section 3.3.1, results shown in Figure 1c,g). We also explored the breadth of this combined method by testing nine fluoropolymers (Table S5b). 1D 19F NMR results showed that two PVDF-based fluoropolymers (PVDF and PVDF-HFP) could be detected due to their dissolution in 80%/20% DMSO/acetone (heated to 100−120 °C), with their 1D 19F NMR patterns (Figure S7a and Text S9) matching well with earlier reports for PVDF. 39 Seven other fluoropolymers (polytetrafluoroethylene or PTFE, chlorotrifluoroethylene or PCTFE, ethylene tetrafluoroethylene or ETFE, ethylenechlorotrifluoroethylene or ECTFE, fluorinated ethylene propylene or FEP, perfluoroalkoxy polymer or PFA, and polyvinyl fluoride or PVF, Table S5b) could not be detected, due to their poor solubility in water and all organic solvents tested (e.g., DMSO/acetone), 40 even at temperatures up to 120 °C. 2D DOSY 19F NMR (Figure S7b) determined that the diffusion coefficients (log D:−11.0 to −10.7) [m2/s]) of PVDF in 80%/20% DMSO/acetone were an order of magnitude lower than those reported for other fluoropolymers (e.g., PCTFE) in chloroform (log D: (−10 to −9.1) [m2/s]), possibly due to the different solvents used for dissolution or the different molecular sizes of these fluoropolymers. Thus, the combined 1D and 2D DOSY 19F-NMR method may only be used to analyze a discrete subset of fluoropolymer types, depending on the dissolution solvent and method (e.g., heating). 3.2. TF and PFAS in Paints. 3.2.1. 19F NMR Analysis. IF was < IDL in all paints. 19 TOF was detected in 36% (22/61) of the paints at concentrations of 0.1−16.1 μmol F/g ww (Figures 2a and S8a), similar to the levels of < IDL−48 μmol F/g reported for paints on the US market. 19 Paints with TOF > IDL had two different 1D 19F NMR spectral patterns that matched 6:2 FTAC or the benzotrifluoride standard, indicating the presence of 6:2 FT or aromatic trifluoromethyl (aromatic-CF3)-containing PFAS (Figure S9a). The low diffusion coefficients of these two types of PFAS (log D:−9.2 to −8.7) derived from 2D DOSY 19F NMR and the low calculated molecular weights (62 or 378−640 g/mol) further confirmed that the PFAS detected were nonpolymeric (Figure S10a and Table S13b). The paints with 6:2 FT nonpolymers had higher detection frequencies (28% vs 8%, Figure S8a) and higher TOF and CnF2n+1 unit concentrations than those with aromatic-CF3 nonpolymers (median TOF: 11.4 vs 0.4 μmol/g ww, median CnF2n+1 unit: 279 vs 8.1 μg/g ww, Figure S11a,b and Table S14a). Previous studies reported 6:2 fluorotelomers in US residential paints and aromatic-CF3nonpolymeric PFAS in US bridge paints; 19,41 our study further revealed that aromatic-CF3 nonpolymeric PFAS were also present in residential paints. 3.2.2. LC-HRMS and LC-MS/MS Analysis. All paints with TOF > IDL (22 paints) contained at least one PFAS, with ΣLC-PFAS (PFAS identified by LC-HRMS and LC-MS/MS) concentrations ranging from 0.002 to 498 μg/g ww (median: 243 μg/g ww) (Figures S12a and S13a). Paints with 6:2 FT nonpolymers had higher ΣLC-PFAS concentrations than those containing aromatic-CF3nonpolymers (median: 288 vs. 0.01 μg/g ww). Paints with TOF < IDL also had PFAS but at a Figure 2. TOF content of paints (a) and sealers (b) after simple extraction and of textiles after simple extraction (c) and hydrolysis (d) for products with TOF > IDL by 1D 19F NMR. Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20645 much lower detection frequency (9% of 11 tested) and lower ΣLC-PFAS levels (median: 5.4 μg/g ww) (Figures S12a and S13a). For paints containing 6:2 FT nonpolymers, targeted analysis showed higher fractions of ΣLC-PFAS than suspect and nontargeted analysis (75−100% versus 0−25%) (Table S15a). Eighty-two to 100% of the paints containing 6:2 FT nonpolymers contained 6:2 mono-, di-, and tri-PAPs and 6:2 dipyrophosphate at concentrations of 0.3−73.7, 14.2−333, 0.8−7.0, and 3.5−87.6 μg/g ww, respectively, which summed to 17.2−498 μg/g ww. These compounds accounted for 99.9− 100% of ΣLC-PFAS (Figure S13a). In contrast, other PFAS (including perfluoroalkyl carboxylic acids (PFCAs) or perfluoroalkanesulfonic acids (PFSAs)) accounted for only 0−0.07% of ΣLC-PFAS (Σother PFAS: 0−0.26 ug/g ww). The abundance of these various PAP compounds contrasted with previous reports of only 6:2 diPAP in US residential paints and traffic paints. 19,41 These four compounds may be added as “active” ingredients or could be unreacted intermediates or byproducts. 42 Notably, this is the first report of 6:2 monoand tri-PAPs and 6:2 dipyrophosphate in paints. Several PFAS found in Chinese fluorocarbon paints, 43 including hexafluoropropylene oxide oligomers (HFPO oligomers), polyether perfluoroalkyl carboxylic acid (Poly PFECAs), monohydro-substituted perfluoroalkyl carboxylic acids (H-PFCAs), and polyfluorinated sulfates (PFSs) were not detected in the paints tested (Table S17). 3.2.3. GC/MS Analysis. We found PFAS in 95.5% of the paints with TOF > IDL, with ΣGC-PFAS (PFAS identified by GC-MS) concentrations of 0.5−41.5 μg/g ww (median: 3.7 μg/g ww) (Figures S15a and S16a). The ΣGC-PFAS concentrations in those paints with 6:2 nonpolymers were much higher than those in the ones with aromatic-CF3 nonpolymers (median: 5.4 vs 1.0 μg/g ww) (Figure S16a). Ninety-four percent of the paints with 6:2 FT nonpolymers had 6:2 FTOH, with levels (<LOD−41.5 μg/g ww) comparable to those in the US paints (0.9−83 μg/g ww). 19 Four percent of the paints with aromatic-CF3nonpolymers contained PCBTF at concentrations of 0.7−12.7 μg/g ww (Figure S15a and Table S16a). Kim-Fu et al. recently identified PCBTF in bridge paints, 41 and our study shows that PCBTF may also be present in residential paints. 3.2.4. Closing the Mass Balance for Paints. Nonvolatile 6:2 mono-, di-, and triPAPs and 6:2 dipyrophosphate accounted for 28−66% of TOF in most of the 6:2 FT nonpolymercontaining paints (except for 2.5% in one, Figure 3a). Volatile 6:2 FTOH and 6:2 FTMAC accounted for an additional 0.7− 11% of TOF (except for 0% in one). These six PFAS together contributed to 36−68% of TOF (except for 3.3% in one) in the paints with 6:2 FT nonpolymers, in contrast with 1.9−10% of TOF consisting of 6:2 diPAP and 6:2 FTOH in the US residential paints. 19 The sum of ΣLC-PFAS and ΣGC-PFAS (F equivalent) explained 3.8−16% of TOF in the paints with aromatic-CF3nonpolymers, leaving most TOF unknown and warranting future study. 3.3. TF and PFAS in Sealers. 3.3.1. 19F NMR Analysis. IF was not detected in sealers, while TOF was detected in 24% (13/54) at 0.4−2488 μmol F/g ww (Figures 2b and S8b). This is the first time that the IF and TOF concentrations in sealers have been examined. Sealers with TOF > IDL had four distinct patterns (Figures 1a-c and S9b), with two patterns (Figure 1a,b) similar to those in paints: the first one included 6:2 FT nonpolymers, the second one aromatic-CF3nonpolymers. The other two patterns had 6:2 FT SCFPs and perfluorobutane sulfonyl fluoride (PBSF)-based PFAS (Figures 1c, S9b, and S10a-c). Different chemical shifts in the 1D 19F NMR spectra of the Figure 3. Comparison of TOF determined by 19F NMR with fluorine equivalents from PFAS (e.g., 6:2 mono-, di-, triPAP and dipyrophosphate and others) identified by LC-HRMS/LC-MS/MS and from PFAS (e.g., 6:2 FTOH, 6:2 FTMAC, MeFBSE, and others) identified by GC-MS after simple extraction of paints (a) and sealers (b), after simple extraction (c) and hydrolysis (d) of textiles with TOF > IDL by 19F NMR. Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20646 aromatic-CF3PFAS in sealers (Figure 1a) indicated that they differed from those found in the AFFF-impacted water. 34 The identification of PBSF-based PFAS in one sealer was based on its 1D 19F NMR spectral pattern that matched well with the MeFBSE standard (Figure S9b). The low PFAS concentration prevented us from distinguishing the nonpolymeric or polymeric form by 2D DOSY19F NMR. The determination of 6:2 FT SCFPs in the two sealers that listed fluorinated polymers on their labels was based on their much broader peak resonances relative to 6:2 FT nonpolymers in the 1D 19F NMR spectra, an order-of-magnitude lower diffusion coefficient (log D:−9.9 to −9.7 [m2/s]), and their much higher estimated MWs (11990−43260 g/mol) compared with the 6:2 FT nonpolymers in 6:2 diPAP/6:2 FTOH standards (log D:−9.3 to −8.9 [m2/s], MWs: 141−1105 g/mol) derived from 2D DOSY19F NMR (Figures 1c,g and S10c, Table S13b, and Text S9). As previously reported, poor molecular rotation and repeating units situated in marginally different chemical environments of polymers could result in broad peaks. 44 After hydrolysis, the resonances formerly assigned to 6:2 FT SCFPs showed similarly narrow peak resonances, a comparable diffusion coefficient (log D:−9.2 [m2/s]), and similar estimated MWs (491−640 g/mol) to 6:2 FT nonpolymers in 6:2 diPAP/6:2 FTOH standards (Figures 1d, h and S10c and Table S13b). This change after hydrolysis was consistent with the transformation of large 6:2 FT SCFPs to smaller 6:2 FT nonpolymers during hydrolysis, which may be due to the cleavage of the fluorinated side chains from the nonfluorinated backbone or breakdown of the nonfluorinated backbone. 45 Our study uncovered, for the first time, the use of 6:2 FT SCFPs in sealers. Rigler et al. 46 reported that indoor bathroom tile grout contained 1% acrylic fluorinated polymer, which was not further characterized. Notably, the dominance of 6:2 FT SCFPs in the two Canadian sealers (L-002 and L-004) labeled as fluorinated contrasted with the dominance of 6:2 FT nonpolymers in the US sealer labeled as fluorinated that we tested (O-008, Figure 2b). As with paints, sealers with 6:2 FT nonpolymers showed higher detection frequencies and higher TOF and CnF2n+1 unit concentrations than those with aromatic-CF3nonpolymers (11% vs 7%, median TOF: 20.8 vs. 1.5 μmol/g ww, median CnF2n+1 unit: 510.6 vs. 35.0 μg/g ww) (Figures 1b, S8b, and S11c,d and Table S14b). Sealers with 6:2 FT SCFPs accounted for only 4% of the sealers tested but had the highest concentrations (median TOF: 904 μmol/g ww, median CnF2n+1 unit: 22190 μg/g ww). Only 2% of the sealers had PBSF-based PFAS, with median TOF and CnF2n+1 unit concentrations of 2.3 and 55.7 μg/g ww, respectively (Figures 1b and S11c,d). 3.3.2. LC-HRMS and LC-MS/MS Analysis. Sealers with TOF > IDL showed much higher detection frequencies and ΣLCPFAS concentrations than those with TOF < IDL (100% vs 40%, median: 1.6 vs < IDL μg/g ww; Figures S12b and S13b and Table S15b). The highest ΣLC-PFAS levels were found in the sealers with 6:2 FT nonpolymers compared to those with other types of PFAS (median: 765.3 and 0.03−2.2 μg/g ww, respectively) (Figure S12b), again dominated by 6:2 mono-, di-, and tri-PAPs and 6:2 dipyrophosphate in the former (Figure S13b). Our study presented new findings on the presence of 6:2 mono-, di-, and tri-PAPs and 6:2 dipyrophosphate in sealers. Similar to paints, targeted analysis revealed much higher fractions of ΣLC-PFAS than suspect and nontargeted analysis (78−100% vs 0−22%) in sealers containing 6:2 FT nonpolymers (Table S15b). Notably, 1 out of the 2 sealers with 6:2 FT SCFPs was dominated by 6:2 fluorotelomer sulfonamide betaine (6:2 FTAB) and C3−C7 PFCAs that explained 85% of ΣLC-PFAS. This is the first time that 6:2 FTAB has been identified in sealers, representing another source of 6:2 FTAB detected in the environment 47 and biota in addition to AFFFs. 27 3.3.3. GC/MS Analysis. The ΣGC-PFAS concentrations in all sealers with TOF > IDL were 0.6−354 μg/g ww (median: 6.7 μg/g ww) and did not differ significantly among sealers with different types of PFAS (p> 0.05) (Figures S15b and S16b). 6:2 FTOH was commonly detected in the sealers with 6:2 FT nonpolymers and 6:2 FT SCFPs at concentrations of 0.4−354 and 212−304 μg/g ww (median: 8.1 vs. 257.6 ug/g ww), respectively, which contributed 69−100% to ΣGC-PFAS. 6:2 FTMAC was only detected in the 6:2 SCFPs-containing sealers at 5.9−35.3 μg/g ww (median: 20.6 μg/g ww), while MeFBSE was only detected in the sealer with PBSF-based PFAS (51.2 μg/g ww) (Figure S15b). Consistent with the detection of long-chain FTOHs (8:2, 10:2) in a European sealer, 16 we observed low levels (0.036−0.067 μg/g ww) of 8:2 FTOH in one sealer with aromatic-CF3nonpolymers (Figure S15b). All sealers with the aromatic-CF3nonpolymers contained detectable PCBTF at concentrations of 1.6−5.7 μg/g ww (Figure S15b,Table S16b). 3.3.4. Closing the Mass Balance for Sealers. In the sealers with 6:2 FT nonpolymers, nonvolatile 6:2 mono-, di-, and triPAPs and 6:2 dipyrophosphate accounted for 61−100% of TOF (except for 0.24% in one), while volatile PFAS only contributed to 0.2−5% of TOF (Figure 3b). Volatile MeFBSE was the major contributor of TOF (54%) in the sealer with PBSF-based compounds. For the sealers with SCFPs, the sum of ΣLC-PFAS and ΣGC-PFAS (F equiv) explained only 0− 1.5% of TOF, indicating that 19F NMR analysis is useful for identifying TOF and PFAS composition. The sum of ΣLCPFAS and ΣGC-PFAS (F equiv) contributed to 1.3−9.6% of TOF in the sealers with aromatic-CF3nonpolymers (Figure 3b), leaving most TOF unknown and warranting future research. 3.4. TF and PFAS in Textiles. 3.4.1. 19F-NMR Analysis. 57% (17/30) of the textiles had detectable levels of TOF in the range of 0.04−0.50 μmol F/g (or 0.14−1.7 μmol F/m2) after simple extraction (Figures 1c and S8c), which increased after hydrolysis to 70% (21/30) with 3−1700-fold higher concentrations (0.34−74.0 μmol F/g or 0.30−19.3 μmol/ m2) (Figures 1d and S8d). This was also demonstrated for clothing, where hydrolysis increased TF by 9−1700-fold and the levels of FTOHs by 3−1300-fold compared to simple extraction. 23,24 After hydrolysis, the textiles showed 1D 19F NMR patterns that matched with standards, indicating three kinds of precursors, namely 8:2 FT, 6:2 FT, and PBSF-based (Figure S9c). These PFAS compounds were consistent with those reported for garments and medical textiles. 17,32 The PFAS freed up by hydrolysis in textiles included chemically bound FTOHs/MeFASEs and other PFAS likely from SCFPs or other nonpolymeric impurities (see sections 3.4.2 and 3.4.3). 24,48−51 This study demonstrated that 19F NMR can be used to examine the TF/PFAS in textiles. For the three types of precursors in textiles, the TOF and CnF2n+1 unit concentrations followed the order of 8:2 FT > 6:2 FT > PBSF-based (Figures 1c,d and S11e-h and Table S13c,d). The low concentrations of PFAS in the textiles with PBSFbased precursors may have been due to difficulty in Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20647 hydrolyzing PBSF-based SCFPs compared with FT-based SCFPs. 24 3.4.2. LC-HRMS and LC-MS/MS Analysis. After simple extraction, we detected at least one target PFAS in all textiles, with ΣLC-PFAS levels in the textiles with TOF > IDL significantly higher than those with TOF < IDL (p = 0.01, median: 10.2 vs. 4.0 ng/g or 8.8 vs. 2.4 μg/m2) (Figures S12c and S13c). Perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and longer-chain PFCAs were detected in 6.7−73% of the samples at concentrations of 0.03−3.2 ng/g (0.02−2.3 μg/m2) (Figure S13c,d), much lower than 0.01−171 μg/m2detected in outdoor jackets from Germany collected in 2011−2012. 15 After hydrolysis, ΣLC-PFAS concentrations in 87% of the textiles increased by 28−1200 times compared with simple extraction (Figures S13c-f and S17a). Textiles with TOF > IDL still had higher detection frequencies and concentrations than textiles with TOF < IDL (p< 0.01, 100% vs. 89%; median: 109 vs. 4.0 ng/g or 103 vs. 4.3 μg/m2;Figures S12d and S13e,f). Hydrolysis increased levels of short-chain PFAS in the textiles with 6:2 FT or PBSF-based precursors, specifically, 5:3 fluorotelomer carboxylic acid (FTCA) for the former and perfluorobutanesulfonic acid (PFBS), perfluorobutane sulfonamide (FBSA), and MeFBSA for the latter. Those textiles with 8:2 FT precursors had higher levels of long-chain PFAS (e.g., 7:3 FTCA, PFOA) (Figure S13e,f), which possibly resulted from the degradation of 8:2 FT-based SCFPs or other unreacted synthesis intermediates (e.g., 8:2 FTOH). 14,52−54 Thus, these textiles used in exterior applications could constitute sources of long-chain (e.g., 7:3 FTCA, PFOA) and short-chain (e.g., 5:3 FTCA, PFBS, FBSA) PFAS to the environment under certain conditions (e.g., in landfill leachates with basic conditions). 55−57 After simple extraction, targeted analysis revealed 3.2−100% of ΣLC-PFAS, while suspect and nontargeted analysis found 0−97% (Table S15c,d). After hydrolysis, this changed to 67− 100% by targeted analysis and 0−33% by suspect and nontargeted analysis (Table S15e,f), indicating the conversion of some precursors to detectable target PFAS after hydrolysis. These results highlighted the importance of combining targeted, suspect, and nontargeted analysis for PFAS characterization in textiles. Some emerging PFAS alternatives, 58 including hexafluoropropylene oxide dimer acid (HFPO− DA), 6:2 FTCA, and 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA, trade name F-53B), were not detected in the tested textiles after simple extraction or hydrolysis treatment (Table S17). 3.4.3. GC-MS Analysis. All 30 textiles had detectable PFAS, with ΣGC-PFAS concentrations after hydrolysis 2−1470 times higher than after simple extraction (Figures S15c-f, S16c,d, and S17b). The ΣGC-PFAS levels were significantly higher than ΣLC-PFAS after simple extraction and hydrolysis treatment (p < 0.01, median: 508 vs. 8.7 ng/g, and 17990 vs 69.7 ng/g, respectively), indicating the prevalence of volatile PFAS in these textiles, consistent with measurements of industrial textiles and outdoor clothing. 15,59−61 The major volatile PFAS after simple extraction and hydrolysis were 6:2 FTOH, 8:2 FTOH, and MeFBSE, for textiles with 6:2 FT, 8:2 FT, and PBSF-based compounds, respectively (Figure S15c-f), similarly to previous studies of clothing, industrial, and upholstery fabrics. 15,16,62 n:2 FTOHs and MeFASE can be used to make nonpolymeric PFAS that includes acrylates and methacrylates, which are further used to synthesize SCFPs. 63,64 Therefore, FTOHs/MeFASE present in the textiles after simple extraction were likely present not as active ingredients in the textile treatment processes but as unreacted raw materials, intermediates, or byproducts when synthesizing SCFPs 15,60 and/or the breakdown products of SCFPs. 65 3.4.4. Closing the Mass Balance for Textiles. In the textiles with 8:2 FT, 6:2 FT, and PBSF-based compounds, volatile 8:2 FTOH, 6:2 FTOH, or MeFBSE were the major contributors to TOF, respectively. These PFAS constituted as percentages of TOF, 160%, 4.3−469%, and 6.2−30% (except for 192% in one), respectively, after simple extraction (Figure 3c), whereas after hydrolysis they contributed 125%, 22.4−70.3%, and 38.0−105.6% (except for 186−418% in three), respectively (Figure 3d). In contrast, the nonvolatile ΣLC-PFAS contributed to 0.07−4.2% and 0.002−3.4% of TOF after simple extraction and hydrolysis, respectively (Figure 3c,d). Percentages < 100% of TOF explained by the sum of ΣLC-PFAS and ΣGC-PFAS (F equivalents) in most textiles with 6:2 FT and PBSF-based precursors indicated the presence of unknown organic fluorine in these textiles. The percentages > 100% of TOF in certain textiles was puzzling; one explanation could be the higher sensitivity of GC-MS than 19F NMR. 4. ENVIRONMENTAL IMPLICATIONS We advanced analytical methods for analyzing TF, TOF and PFAS by establishing a fast-screening method of 1D and 2D DOSY solution-state 19F NMR that can differentiate organic from inorganic fluorine, quantify TOF content, characterize different types of PFAS, as well as distinguish between SCFPs and nonpolymeric PFAS. The method can also quantitatively determine SCFPs in units of mass of CnF2n+1 per gram of paints/sealers/textiles, as opposed to F equivalents, which could support the estimation of the quantity of PFAA degradation products with specific carbon chain lengths. The method can be extended to a large variety of products containing SCFPs, including firefighting foams, inks, lacquers, varnishes, car seats. 48,49,51,66 A major limitation of this combined 19F NMR method is the detection of only extractable or dissolvable PFAS, which here excluded fluoropolymers and some other polymeric PFAS (e.g., highmolecular-weight perfluoropolyethers). In addition, similar to other 19F NMR methods, 34,36 this combined method has lower sensitivity but is more rapid than advanced mass spectrometry methods. Our results showed that many paints, sealers, and textiles purchased in Canada and mostly intended for exterior use contained a variety of nonpolymeric PFAS and/or SCFPs. These findings are likely relevant to other jurisdictions given the (hitherto) high integration of Canadian and US markets. 67 Most abundant in the products were precursors that could degrade to short-chain PFCAs. For instance, the abundant 6:2 mono-, di-, and triPAPs in paints/sealers and 6:2 FTOH in paints and textiles can degrade into a series of short-chain PFCAs, 68−70 and the 6:2 FT SCFPs in a few sealers may also form short-chain PFCAs (e.g., PFHxA). 71,72 These short-chain PFCAs can readily migrate into surface and groundwater and eventually to drinking water, owing to their persistence, low sorption potential, and high mobility. 73 We also found low, but measurable, levels of PFOA, PFOS, and long-chain PFCAs in a few paints/sealers/textiles as well as a high abundance of longchain precursors (e.g., 8:2 FTOH) that may degrade into longchain PFCAs (≥C8) in one textile, despite the restricted use or phase-out of PFOS, PFOA, and long-chain PFAAs in Canada Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20648 and the US since 2000−2015. 11,21,74 These long-chain PFAAs persist in soil and accumulate in biota. 75 The PFAS-containing paints, sealers, and textiles could release PFAS to the environment, through direct wash-off with precipitation of nonvolatile PFAS to soil and stormwater and surface waters and volatilization of volatile PFAS to air, with the potential for atmospheric transformation followed by deposition to soil and surface water. Once in water, these PFAS are difficult and costly to remove. 76 An indirect line of evidence for PFAS release is declining performance of exterior paints, sealers, and textiles, and hence the need to reapply paints and sealers over time. Paints and sealers provide important functions of protecting structural surfaces such as wood, concrete, and brick from deterioration and preventing moisture penetration, thereby reducing lifecycle material use and costs of buildings. Fortunately, the absence (lack of detection) of PFAS in 89 of 145 (61%) of the paints, sealers, and textiles obtained from the Canadian market (and one US product) indicates that alternatives are not only available but are widely available on the market. 6 But unfortunately, consumers are not able to choose PFAS-free products since only 3 of 145 products (2%) were labeled as containing PFAS, and we found no relationship between marketing terms (e.g., resistant to weathering, mildew, and/or UV) and the presence of PFAS. Our results point to the need for these industries to accelerate the replacement of PFAS in building products with less persistent and hazardous alternatives, driven by regulations with a clear timetable for PFAS elimination. ■ASSOCIATED CONTENT * sı Supporting Information The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.est.5c07012. Explanations and lists of chemicals, solvents, and materials used, details of sample preparation and analytical methods, summary of QA/QC including for spike recovery tests and matrix tests, determining nonpolymeric and SCFPs based on 1D and 2D DOSY 19F NMR, summary of previous research on TF and PFAS in paints, sealers, textiles, and other building products, details of products tested, list of all standards used, acquisition methods for UHPLC-HRMS analysis, details of 19F NMR methods, summary of PFAS detected in products using LC-HRMS suspect and nontarget screening, workflow for PFAS characterization, structures of PFAS sought in target screening, results of matrix effects testing, 19F NMR spectra of samples and standards obtained by 1and 2-D DOSY, number and different types of PFAS in paints and sealers obtained by 19F NMR after simple extraction, concentrations of ΣLC-PFAS in paints, sealers, and textiles (after simple extraction or after hydrolysis), detailed analysis of PAPs and dipyrophosphate and other PFAS in sealers and textiles, concentrations of ΣGC-PFAS, comparison of ΣLC-PFAS and ΣGC-PFAS of textiles after simple extraction and hydrolysis (PDF) Tables S7−S12, S14−S16 (XLSX) ■AUTHOR INFORMATION Corresponding Author Miriam L. Diamond −Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada; School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada; orcid.org/0000-0001-62966431; Email: [email protected] Authors Min Liu −Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada; Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada; Department of Chemistry, Universitéde Montréal, Montréal, Québec H3C 3J7, Canada Chunjie Xia −Paul H O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States; orcid.org/0000-00022497-1907 Hui Peng −Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada; School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada; orcid.org/0000-0002-2777-0588 Elizaveta Zvereva −Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada; Present Address: Faculty of Health Sciences, Global Health Office McMaster University, 1280 Main St. West, MDCL 3500, Hamilton, Ontario, Canada L8S 4K1 Darcy C. Burns −Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada; orcid.org/0000-0001-5411-3930 Justine Fontaine −Department of Chemistry, Universitéde Montréal, Montréal, Québec H3C 3J7, Canada Arlene Blum −Green Science Policy Institute, Berkeley, California 94709, United States Ariana Z. Spentzos −Green Science Policy Institute, Berkeley, California 94709, United States; orcid.org/0000-00019172-6920 Zhanyun Wang −Empa−Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, CH-9014 St. Gallen, Switzerland; orcid.org/ 0000-0001-9914-7659 Graham F. Peaslee −Department of Physics and Astronomy, University of Notre Dame, Notre Dame, Indiana 46556, United States; orcid.org/0000-0001-6311-648X Sébastien Sauvé −Department of Chemistry, Universitéde Montréal, Montréal, Québec H3C 3J7, Canada; orcid.org/0000-0001-8584-1690 Marta Venier −Paul H O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States; orcid.org/0000-00022089-8992 Complete contact information is available at: https://pubs.acs.org/10.1021/acs.est.5c07012 Notes The authors declare no competing financial interest. ■ACKNOWLEDGMENTS We appreciate the donation of PFAS standards from Scott Mabury’s lab group, Amila de Silva at Environment and Climate Change Canada, and the USEPA via Evotec SE. We thank Jeremy Gauthier for his guidance with 19F NMR Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20649 instrument use (at University of Toronto). Funding was provided by Environment and Climate Change Canada (Agreements 300073854 and 3000755885), the Natural Science and Engineering Research Council (NSERC RGPIN2023-05451), the Tides Foundation, European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101036756, project ZeroPM: Zero pollution of persistent, mobile substances, and the New Frontiers in Research Fund Exploration (Canada, NFRFE 2022-00274). Special thanks go to Lisa Sealock and Stacey Chertwaty of Environment and Climate Change Canada. ■REFERENCES (1) Agency, U. S. E. P. Comptox Chemicals Dashboard, Version 2.2.0. U.S. Government Publishing Office: Washington, D.C., 2023. https:// comptox.epa.gov/dashboard/. (2) Dickman, R. A.; Aga, D. S. A review of recent studies on toxicity, sequestration, and degradation of perand polyfluoroalkyl substances (PFAS). J. Hazard. Mater. 2022,436, 129120. (3) Gaines, L. G. 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U.S. Government Publishing Office: Washington, D.C., 2021. https://www.epa.gov/system/files/documents/2021-09/ method_1633_draft_aug-2021.pdf. (32) Schellenberger, S.; Liagkouridis, I.; Awad, R.; Khan, S.; Plassmann, M.; Peters, G.; Benskin, J. P.; Cousins, I. T. An outdoor Environmental Science & Technology pubs.acs.org/est Article https://doi.org/10.1021/acs.est.5c07012 Environ. Sci. Technol. 2025, 59, 20642−20652 20650