This study looked at the effect of ageing, washing and tumble drying PFAS-based water-resistant fabric coatings on the presence of such chemicals. The researchers say that these processes increased the levels of PFASs being detected and released, and they argue for wider-ranging restrictions on these substances.
Per- and poly-fluoroalkyl substances (PFASs) are organic compounds containing fluorine that do not degrade; consequently, they are sometimes referred to as ‘forever chemicals’. There are thousands of specific PFASs, with a range of consumer and industrial uses. Some of these chemicals have been identified as posing risks to human health and the environment such as liver damage and raised cholesterol levels. Several are listed under the Stockholm Convention on Persistent Organic Pollutants and are restricted within the EU, while others have been scheduled or proposed for restriction.
Concerns over the use of PFASs have led to alternatives being explored for durable water-resistant coatings for outdoor wear such as jackets, ski trousers and gloves. Some of these have used entirely different compounds but others rely on currently unrestricted PFAS chemicals of high concern that are used in the manufacture of the repellent coating. Studies have also shown that as the coated material ages, the level of PFASs of concern can increase. This study aimed to add to the knowledge regarding this phenomenon by assessing the effect of washing and tumble drying on the presence of PFASs in treated materials.
The researchers tested two different fabric coatings – one based on PFAS chemistry that has been phased-out and one that is still in use – on two different textiles – polyamide (or ‘nylon’, common in tights and swimwear) and polyester (common in shirts and bedding). For each of the four coating/textile combinations they measured the levels of extractable PFASs – chemicals that were released by the fabric – under different conditions, assessing the effects of ageing, washing and drying. Ageing was simulated in the laboratory by subjecting materials to raised temperature, humidity and ultraviolet light for 300 hours.
The level of extractable PFASs in original material was higher in the polyamide than in the polyester fabric, report the researchers, with more PFAS detected in the old-style coating than the newer one. The researchers say that ageing increased the level of PFASs in the polyamide material, while in the polyester it led to increases in some PFAS and decreases in others. In both cases, they say, ageing also led to the detection of PFASs that had not been found in the original material – several physical or chemical processes could be responsible for the emergence of these chemicals.
The level of many PFASs was reduced by washing and drying in all the fabrics, according to the researchers, suggesting that these were released from the material and potentially transferred into the environment. However, they say that washing and drying the polyester with the new coating and the polyamide with both coatings increased the detected amount of fluorotelomer alcohols – a family of PFASs which can degrade into environmentally-persistent perfluoroalkyl acids. In one case, say the researchers, the fluorotelomer alcohol level was reduced after washing and drying. In their view, this indicates that this substance is both generated and removed by washing/drying but in different proportions in each case leading to positive or negative overall changes.
A further set of tests, focusing on the polyamide material with the new coating, indicated that the level of fluorotelomer alcohol was affected only by washing and not by the tumble-drying process.
Ageing and washing can substantially increase the amount of PFASs in a fabric, say the researchers. Many of these can be removed by washing, entering the environment through wastewater, they say, while more volatile compounds can be transferred by evaporation. Given the complexities of PFAS chemistry, and the potential for generation of new and possibly restricted PFASs during the use phase, the researchers argue in favour of regulatory restrictions that apply to wider groups of PFASs rather than regulating individual substances separately.
The researchers specifically reference a restriction proposal under the EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation currently in preparation by the Netherlands, Germany, Norway, Denmark and Sweden to cover a wide range of PFAS uses – in support of the statements made in the Environment Council in December 2019. The proponents are expected to submit the proposal to ECHA in January 2023. For more details see: https://echa.europa.eu/hot-topics/perfluoroalkyl-chemicals-pfas
Van der Veen, I., Schellenberger, S., Hanning, A-C., Stare, A., de Boer, J., Weiss, J. M. and Leonards, P. E. G. (2022) Fate of Per- and Polyfluoroalkyl Substances from Durable Water-Repellent Clothing during Use. Environmental Science & Technology 56(9): 5886–5897
To cite this article/service:
“Science for Environment Policy”: European Commission DG Environment News Alert Service, edited by the Science Communication Unit, The University of the West of England, Bristol.
Notes on content:
The contents and views included in Science for Environment Policy are based on independent, peer reviewed research and do not necessarily reflect the position of the European Commission. Please note that this article is a summary of only one study. Other studies may come to other conclusions
- Data di pubblicazione
- 30 novembre 2022
- Direzione generale dell’Ambiente