Freshwater ecotoxicity characterization factors for PFASs

Area of Science:

• Environmental Science
• Ecotoxicology
• Life Cycle Assessment

Background:

• Data gaps exist for freshwater ecotoxicological characterization factors (CFs) of per- and polyfluoroalkyl substances (PFASs).
• Accurate CFs are crucial for integrating PFAS ecotoxicity impacts into life cycle assessments (LCAs).
• Existing models may not fully capture the complexity of PFAS behavior in aquatic environments.

Purpose of the Study:

• To calculate a comprehensive set of experimental aquatic ecotoxicity CFs for 367 PFASs using the USEtox model.
• To compare CFs derived from the standard USEtox model with those from a PFAS-adapted USEtox model.
• To investigate potential correlations between PFAS CFs/effect factors and their perfluorinated carbon chain length.

Main Methods:

• Selected 367 PFASs from CompTox Chemicals Dashboard and REACH registration dossiers.
• Extracted experimental ecotoxicity data from CompTox and REACH databases.
• Calculated CFs using both the standard USEtox model (v2.13) and a PFAS-adapted USEtox model, with 237 new CFs generated via HC20EC10eq methodology.

Main Results:

• Calculated 237 new experimental aquatic ecotoxicity CFs for PFASs, enhancing LCA data availability.
• Found no significant correlation between the number of perfluorinated carbons and calculated effect factors or CFs.
• Observed discrepancies between USEtox and PFAS-adapted USEtox CFs, attributed to differences in fate and exposure modeling, not ecotoxicity.

Conclusions:

• The study successfully expanded the dataset of freshwater ecotoxicity CFs for PFASs.
• PFAS ecotoxicity characterization factors are influenced by the modeling approach used.
• Regular updates with the latest data are essential for accurate and relevant PFAS CFs in LCAs.