CEC05-02 Risk Assessment Methodologies

Risk assessment is a specialized field of applied science that involves reviewing scientific data in order to evaluate risks associated with certain hazards (EFSA glossary^[1]). A hands-on training activity on selected methodologies implemented in human health risk assessment will be offered during the Continuous Educational Course (CEC05) on “Regulatory Toxicology in the context of the EU Legislations”. The session will include an introductory presentation and practical exercise on methodologies used in risk assessment of pesticides in the frames of Regulation No. (EC) 1107/2009 and No. (EU) 528/2012. The aim of this activity is to describe how adversity is assessed in key regulatory studies, demonstrate how all available scientific data can be used in weight-of-evidence assessments integrating non-animal approaches. The identification of endocrine disruptors will be used as a specific example.

Weight of evidence (WoE) assessment is a structured approach for transparent and scientifically robust evaluation of the available data. Evaluation of endocrine-disrupting properties using comprehensive WoE assessment is outlined in the respective EFSA/ECHA Guidance (2018). The assessment process includes (i) collecting the evidence, by gathering data from various sources, such as in vitro and in vivo studies, databases, and computational models, to identify potential endocrine adversity and activity; (ii) developing lines of evidence, where collected data are organized into coherent lines taking into consideration reliability, relevance and consistency, and (iii) integrating the evidence by analyzing lines of evidence while assessing uncertainties.

New approach methodologies (NAMs) enhance the reliability of risk assessments while reducing the need for animal testing. NAMs may include but are not limited to Adverse Outcome Pathways (AOP), readacross, in silico, in chemico, and in vitro methodologies, omics and other systems biology-based approaches, and combinations of these in defined approaches or integrated approaches in testing and assessment

(IATAs). Distinguishing between threshold and non-threshold modes of action is critical in hazard characterisation of substances. Hazard characterisation of endocrine disruptors is a concept of scientific and regulatory debate. Development of quantitative AOPs (qAOPs) is expected to provide scientific support towards this approach.

Reviewing risk assessment methodologies including mapping of current practices, uptake of new scientific and technological advancements and identification of areas for improvement is a key task in the European Partnership for the Assessment of Risks from Chemicals (PARC). Overall, by integrating scientific concepts in practical exercises participants will enhance their understanding of transparent and reliable risk assessment.