Per and polyfluoroalkyl substances (PFAS) are widely used chemicals often referred to as ‘forever chemicals’ because they do not readily break down in the environment. Because PFAS have been linked with adverse health effects, cases of drinking water contamination have prompted considerable community concern in New South Wales (NSW). 

However, the three types of PFAS currently regulated in drinking water in Australia (PFOS, PFOA and PFHxS) represent only a small fraction of the thousands of types of PFAS. Data on the health effects of these other PFAS types are limited, but it is clear that some have the potential to be as harmful as PFOS, PFOA and PFHxS, others seem to be less harmful, and all are environmentally persistent. 

Regulators face considerable challenges in determining which of these PFAS warrant regulation. This paper considers case studies of how different overseas jurisdictions have approached these challenges, which PFAS they have chosen to regulate, and current debates that are shaping these decisions. ​​The purpose of this paper is to inform discussions about which types of PFAS should be regulated in NSW by exploring these case studies.

Key points​​

• Regulated PFAS such as PFOS have often been replaced with other types of PFAS. For most PFAS little health data is available, and there are major challenges in determining which types warrant restriction.
• Scientists disagree not only on how to evaluate the risks of different types of PFAS, but on which particular substances should be considered PFAS.
• Some jurisdictions argue that the health effects of exposure to different types of PFAS are likely to be cumulative and therefore apply regulatory limits to the sum of the concentrations of regulated PFAS.
• Some jurisdictions are beginning to restrict the use of all PFAS types, but it is not yet technically feasible to monitor drinking water levels for all types of PFAS.