Aleksandra Dean, Study Director, Environmental Risk Sciences, presented a poster at SETAC Europe's SciCon Meeting
about the comparison of EPA and ECHA guidance on characterization of non-extractable residues (NER) in degradation assessment.
Both the US EPA and ECHA provide approaches for addressing Non-Extractable Residues (NER) are available for laboratory studies. Aleksandra led an evaluation of the two methodologies with environmental fate scientists at Smithers US and UK laboratories, along with scientists from an agrochemical industry partner. The US EPA approach from 2014 used a series of solvents with varying polarity, whereas the ECHA methodology produces different NER fractions with a goal of identifying the relevant fraction for persistence assessment.
Though driven by differing goals in identifying NER, the practicality of the EPA method was found to be superior to that of the ECHA approach. It was observed that the EPA additional extractions collectively removed ≤5% of Applied Radioactivity (AR). The ECHA results displayed similarities between Xeno NER and the amount of radioactivity in the combined fulvic acid and humin fractions of the soil organic matter. The EPA approach is a robust procedure that enables rapid and routine determination of NER, while the ECHA approach in certain respects looks like an approach that will fit into a research context.
To learn more about this topic or to see an overview presentation of Aleksandra's research, visit our SETAC Europe presentation page.