Fate of Per- and Polyfluoroalkyl Substances from Durable Water-Repellent Clothing during Use.

To make outdoor clothing water- or dirt-repellent, durable water-repellent (DWR) coatings based on side-chain fluorinated polymers (SFPs) are used. During use of outdoor clothing, per- and polyfluoroalkyl substances (PFASs) can be emitted from the DWR to the environment. In this study, the effects of aging, washing, and tumble drying on the concentration of extractable PFASs in the DWR of perfluorohexane-based short-chain SFPs (FC-6 chemistry) and of perfluorooctane-based long-chain SFPs (FC-8 chemistry) were assessed. For this purpose, polyamide (PA) and polyester (PES) fabrics were coated with FC-6- and FC-8-based DWRs. Results show that aging of the coated fabrics causes an increase in concentration and formation of perfluoroalkyl acids (PFAAs). The effect of aging on the volatile PFASs depends on the type of fabric. Washing causes a decrease in PFAA concentrations, and in general, volatile PFASs are partly washed out of the textiles. However, washing can also increase the extractable concentration of volatile PFASs in the fabrics. This effect becomes stronger by a combination of aging and washing. Tumble drying does not affect the PFAS concentrations in textiles. In conclusion, aging and washing of fabrics coated with the DWR based on SFPs release PFASs to the environment.

Release of Side-Chain Fluorinated Polymer-Containing Microplastic Fibers from Functional Textiles During Washing and First Estimates of Perfluoroalkyl Acid Emissions.

The quantity and composition of fibers released from functional textiles during accelerated washing were investigated using the GyroWash method. Two fabrics [polyamide (PA) and polyester/cotton (PES/CO)] were selected and coated with perfluorohexane-based side-chain fluorinated polymers. Fibers released during washing ranged from ∼10 to 500 µ with a similar distribution for the two textile types. The PA-based fabric released considerably more fibers >20 µm in length compared to the PES/CO-based fabric (>1000/GyroWash for PA vs ∼200/GyroWash fibers for PES/CO). After one GyroWash (2-15 domestic washes), fibers that contained approximately 240 and 1300 µg total fluorine per square meter (µg F/m2) were released from the PA and PES/CO fabrics, respectively. Current understanding of the fate of microplastic fibers suggests that a large fraction of these fibers reach the environment either in effluent wastewater or sewage sludge applied to land. In the environment, the fluorinated side chains will be slowly cleaved from the backbone of the side-chain fluorinated polymers coated on the fibers and then transformed into short-chain perfluoroalkyl acids. On the European scale, emissions of up to ∼0.7 t of fluorotelomer alcohol (6:2 FTOH) per year were estimated for outdoor rain jackets treated with fluorotelomer-based side-chain fluorinated polymers.

The effect of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing.

To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing, thirteen commercial textile samples were exposed to elevated ultra violet (UV) radiation, humidity, and temperature in an aging device for 300 h, which mimics the lifespan of outdoor clothing. Before and after aging, the textile samples were extracted and analysed for the ionic PFASs (perfluoroalkyl acids (PFAAs), perfluorooctane sulfonamide (FOSA)) and volatile PFASs (fluorotelomer alcohols (FTOHs), acrylates (FTACs) and methacrylates (FTMACs)). Results showed that weathering can have an effect on PFASs used in DWR of outdoor clothing, both on the PFAS profile and on the measured concentrations. In most weathered samples the PFAA concentrations increased by 5- to more than 100-fold, while PFAAs not detected in the original textiles were detected in the weathered samples. DWR chemistries are based on side-chain fluorinated polymers. A possible explanation for the increase in concentration of the PFAAs is hydrolysis of the fluorotelomer based polymers (FTPs), or degradation of the FTOHs, which are used in the manufacturing of the FTPs. The concentrations of volatile PFASs also increased, by a factor up to 20. Suggested explanations are the degradation of the DWR polymers, making non-extractable fluorines extractable, or the transformation or degradation of unknown precursors. Further research is needed to unravel the details of these processes and to determine the transformation routes. This study shows that setting maximum tolerance limits only for a few individual PFASs is not sufficient to control these harmful substances in outdoor clothing.

Development and validation of a method for the quantification of extractable perfluoroalkyl acids (PFAAs) and perfluorooctane sulfonamide (FOSA) in textiles.

In textiles, like outdoor clothing, per- and polyfluoroalkyl substances (PFASs) are often used for durable water repellency (DWR) of the final products. The analytical performance to determine the concentration of these chemicals available for exposure to humans and to the environment need to be established. Here a method for the extraction and analysis of one class of PFASs, namely perfluoroalkyl acids (PFAAs), in outdoor clothing was developed and validated. The PFAAs which were validated, included perfluoroalkyl carboxylic acids (PFCAs) (C4-C14), and perfluoroalkane sulfonic acids (PFSAs) (C4, C6, C7, C8). In addition, perfluorooctane sulfonamide (FOSA) was included in this study. The method was based on an organic solvent extraction and analysis by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). No further cleaning was needed. Two commonly used organic solvent compositions were evaluated for the optimal extraction, i.e. methanol and acetone/acetonitrile (80:20, v/v), and the number and duration of the sequential extractions were optimized. Results showed that two sequential extractions with 5mL methanol and an extraction time of 30min gave an optimal performance with an extraction efficiency of >90%. The influence of matrix on the quantification of PFAAs was studied. This indicated ion suppression due to different matrix effects or sorption behavior to specific textile samples. Validation of the entire method showed overall recoveries of>80% and relative standard deviations (RSDs) of<9% (n=3) for repeatability and <20% (n=3) for reproducibility. This is the first validation of an analytical method for the analysis of extractable PFCAs, PFSAs and FOSA associated to textiles, which is of high importance due to the regulation of PFAAs in textile.