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ORD Ecotoxicity Research on New Approach Methods: ecoTTC, HC5n
Barron, M. AND F. Lambert. ORD Ecotoxicity Research on New Approach Methods: ecoTTC, HC5n. Risk Assessment Forum Ecological Oversight Committee, DC (Virtual), Washington, February 22, 2021.
This presentation will present an overview of two new approach methods to estimate aquatic hazard concentrations of chemicals. The impact is that the information is being communicated to senior EPA risk assessors that are members of the Agency's Risk Assessment Forum. Forum members can then use that information to better utilize existing data and create more informed regulations and actions for the public good. Additionally, use of these methods may ultimately reduce the need for animal testing to assess the hazards of new chemicals and existing environmental contaminants with limited data.
This is a power point presentation overviewing two new approach methods to estimate aquatic hazard concentrations of chemicals. The first method is the ecological threshold of toxicological concern (ecoTTC) approach that estimates a no adverse effect concentration using chronic toxicity data for compounds within the same chemical group (e.g., same mode of toxic action; similar structural class). The second method is the toxicity normalized hazard concentration (HC5n) that estimates chemical specific acute hazard concentrations using toxicity data normalized to a single sensitive species. Both of these methods show promise to use existing data and enable the calculation of hazard concentrations for a greater number of chemicals.