Essential to me, essential to you? Heterogeneity in essential use definitions as a barrier to reducing PFAS pollution

The associated health risks of persistent, mobile and toxic chemicals are receiving growing media attention, and regulators are turning to experts for advice on where PFAS (Per- and polyfluoroalkyl substances, colloquially referred to as ‘forever chemicals’) are found, and how to avoid them. One of the key tools to be used by regulators within the EU is the concept of ‘essential use’ (Cousins et al., 2019): this process is designed to guide authorities in deciding when to restrict or authorize certain uses of PFAS, by whether the use of a potentially hazardous chemical within a particular context is deemed ‘essential’ to the functioning of society. But what does something being ‘essential’ mean, and to whom? In this talk, I’ll discuss our ongoing work within EU-project ZeroPM (Zero Pollution of Persistent Mobile Substances): using a mix of qualitative and quantitative approaches, I’ll show how essentiality differs by group, by comparing expert and non-expert models of PFAS risks and benefits. Moreover, I’ll demonstrate the surprising amounts of heterogeneity we find even within just expert populations, and explain how ambiguity within value judgments – like ‘essentiality’ - can create barriers to behaviours intended to reduce PFAS pollution. Finally, I’ll discuss how prior work (e.g., on microplastics) shows that engaging with the public can be a positive driver of change on environmental issues.