Chemical substitution with a life cycle perspective: The case of per- and polyfluoroalkyl substances in durable water repellents

Doctoral thesis, 2020

The aim of the research presented in this thesis was to support the process of substitution of side-chain fluorinated polymers in durable water repellents (DWRs), that give rise to emissions of hazardous per- and polyfluoroalkyl substances (PFASs). The focus was on: i) the provision of improved decision support regarding the environmental and human health performance of alternatives, and ii) public readiness for substitution and what messages can motivate consumers to voluntary substitution.

This research explored the applicability of life cycle assessment (LCA) for the provision of a life cycle perspective in chemical alternatives assessment (CAA). To improve the relevance of LCA in the CAA of DWR alternatives, contributions were made to the life cycle impact assessment (LCIA) of (eco)toxicity, and characterisation factors were calculated (Papers II and III). Case study results (Paper IV), together with a literature review (Paper V), showed that LCA can provide relevant information for CAAs. Potential problem-shifting was identified between DWR alternatives, and the scenario assessment in the LCA provided useful input to the CAA. The hazard assessment (Paper I) together with the LCA support the recommendation to phase-out all non-essential use of PFASs in DWR.

Performing such a phase-out through regulation can be a slow process. The potential to accelerate a phase-out by motivating consumers to voluntary substitution was investigated using a web-survey experiment. This study (Paper VI) found that Swedish readiness to voluntarily act to substitute hazardous fluorinated chemicals is already high and that detailed information on the hazards associated with these chemicals can raise this potential even higher.

The present research strengthens the potential for LCA to be used in CAA and identifies its limitations. The work will help policy makers and analysts who are faced with challenges such as prioritising regulatory and design interventions for substitution and shaping information campaigns to encourage voluntary substitution.