Implementation of the Grouping and Read-Across Approach for the Prediction of Nanomaterials Ecotoxicity

Engineered nanomaterials (ENMs) occur in various products and could be released into the environment during their life cycle. Therefore, it is crucial to assess the potential risk that ENMs may pose through their entire life cycle in order to accurately predict the environmental fate as well as their potential hazards. In this context, we aimed at evaluating the applicability of the available grouping and read-across guidelines for predicting the ecotoxicity of various nanoforms of silica ENMs. We performed a case study using data for amorphous nano-SiO 2 gathered from the JRC Repository characterization dossier and the NanoReg2 H2020 project (i.e. NMs 200, 201, 202, 203, 204). The toxicity results towards a carp leucocyte cell line (CLC) expressed by the EC25 values were considered as the endpoint for the case study. Nanoinformatics methods were applied to perform grouping of ENMs based on their properties. Subsequently, the case study was developed using the Read-Across Assessment Framework (RAAF) on previously established group of similar nanoforms to assess the ecotoxicity of ENMs in the regulatory context. Finally, suggestions and perspectives for the future development of such frameworks, testing protocols, and standardized methods for ENMs were proposed.