A MARINE MODEL FOR PFOA REPLACEMENTS: A CASE STUDY ON THE ENVIRONMENTAL FATE HFPO-DA (GenX)

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic persistent and toxic chemicals. The most common PFAS is perfluorooctanoic acid (PFOA) which has been produced on an industrial scale since the 1950ties. Since the early 2000s the industry has started to replace PFOA with alternative PFAS. One such replacement, advertised under the name GenX, is hexafluoropropylene oxide dimer acid (HFPO-DA). Replacing PFOA with a multitude of alternative PFAS poses a severe problem. Because analytical methods are not available for many of the replacement substances they can be emitted secretly into the environment. For HFPO-DA, our Institute developed a method that allows to detect this substance at environmental levels and we found that it was a major replacement in Europe’s largest PFAS production plant in the Netherlands. First traces were found in the river Rhine in 2008 and in 2015 HFPO-DA concentrations already surpassed those of PFOA. A peak in HFPO-DA production was observed in 2017 and now the replacement seems to have been replaced itself. Based on this well documented episode of HFPO-DA emissions by a major point source into the river Rhine over a period of 16 years we performed a model study to investigate the environmental fate of HFPO-DA. Based on measurements in the North Sea and the North Atlantic Ocean we were able to validate the model for HFPO-DA. This case study is meant to show the feasibility of modelling PFOA replacements in the marine environment. For many of the hundreds of PFOA replacements that are currently in use there are no or only limited observations available. This means that through the replacement of PFOA we are blind to the real extend of PFAS contamination today. Models can allow us to estimate the production capacities even if measurements are only available years after the initial emission of the replacement substance.

Presentation Preference: Oral

Primary Presenter: Johannes Bieser, Helmholtz Zentrum Hereon (johannes.bieser@hereon.de)

Authors:

Johannes Bieser, Helmholtz Zentrum Hereon  (johannes.bieser@hereon.de)

Hanna Joerss, Helmholtz Zentrum Hereon  (hanna.joerss@hereon.de)

Kai Logemann, Helmholtz Zentrum Hereon  (kai.logemann@hereon.de)

Elena Mikheeva, Helmholtz Zentrum Hereon  (elena.mikheeva@hereon.de)