Choosing a rain coating – life cycle assessment to guide substitution of hazardous durable water repellent chemistry
Conference contribution, 2017
Many actors in the textile industry are currently substituting hazardous long-chain per- and polyfluoroalkyl substances (PFAS). One application of PFAS in the textile industry is in finishing to impart water (and oil) resistance to the textile (chemicals that provide this function are called durable water repellents; DWR). In a review of properties of the DWRs that are alternatives to DWRs containing long-chain PFASs, we could show that several of the alternatives also have hazardous properties and that a substitution of the DWR may lead to a shift in the environmental burden of the garment, e.g. by the need of more frequent wash or shorter life length. It is clear that to achieve an environmentally sound substitution thorough assessment of the alternatives is needed.
The project Substitution in Practice of Prioritized Fluorinated Chemicals to Eliminate Diffuse Sources (SUPFES, www.supfes.eu, funded by the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) under grant agreement No. 2012-2148) set out to guide this substitution by assessment of the DWR alternatives, both with regards to their functionality and the environmental consequences of their use. In life cycle assessments (LCA) the environmental performance of four different types of garments (two types of shell jackets, an ambulance jacket and a children’s overall), meeting different user protection needs, are investigated. The LCAs are intended to make possible a holistic assessment where toxicological hazards as well as risks of problem shifting (e.g. between impact categories) are addressed. Connected with technical performance testing of the DWR alternatives the LCAs allow for a unique possibility to include also functionality aspects. One important prerequisite for the LCAs is the availability of characterisation factors for (eco)toxicological effects and a review of existing characterisation factors (CF) for textile chemicals showed that CFs are missing for many DWR-related substances. The calculation of new CFs with UseTox 2.01 made it clear that several of the DWR-related substances are particularly difficult to model due to physical-chemical properties affecting their fate. In addition, many of the substances are persistent, bioaccumulative and toxic (PBT) or very persistent and very mobile (vPvM) and as such their environmental consequences may not be well captured by existing life cycle impact assessment (LCIA) methods, if for example relevant accumulation compartments are not included in the models.
In this contribution we will report on our results from the SUPFES project’s screening LCAs on the four garments and these results’ implications for the DWR substitution case. Which DWR alternative will provide sufficient functionality and environmental soundness, making possible a substitution lasting in the long run? We will also use these cases as basis for the discussion about LCIA methods and practices suitable in substitution cases involving PBT or vPvM substances in general, and PFAS in particular.