An (Eco)Toxicity Life Cycle Impact Assessment Framework for Per- And Polyfluoroalkyl Substances

A framework
for characterizing per- and polyfluoroalkyl substances
(PFASs) in life cycle impact assessment (LCIA) is proposed. Thousands
of PFASs are used worldwide, with special properties imparted by the
fluorinated alkyl chain. Our framework makes it possible to characterize
a large part of the family of PFASs by introducing transformation
fractions that translate emissions of primary emitted PFASs into the
highly persistent terminal degradation products: the perfluoroalkyl
acids (PFAAs). Using a PFAA-adapted characterization model, human
toxicity as well as marine and freshwater aquatic ecotoxicity characterization
factors are calculated for three PFAAs, namely perfluorooctanoic acid
(PFOA) perfluorohexanoic acid (PFHxA) and perfluorobutanesulfonic
acid (PFBS). The model is evaluated to adequately capture long-term
fate, where PFAAs are predicted to accumulate in open oceans. The
characterization factors of the three PFAAs are ranked among the top
5% for marine ecotoxicity, when compared to 3104 chemicals in the
existing USEtox results databases. Uncertainty analysis indicates
potential for equally high ranks for human health impacts. Data availability
constitutes an important limitation creating uncertainties. Even so,
a life cycle assessment (LCA) case study illustrates practical application
of our proposed framework, demonstrating that even low emissions of
PFASs can have large effects on LCA results.