Data collection, hazard characterisation and establishment of cumulative assessment groups of pesticides for specific effects on the thyroid: 2024 update

This report evaluates the thyroid‐related effects of various active substances and metabolites, categorizing them into Cumulative Assessment Groups (CAGs) based on indicators of hypothyroidism and C‐cell effects. 21 active substances and six metabolites were scrutinized resulting in 18 substances and three metabolites for hypothyroidism (CAG‐TCF) and two substances for C‐cell hypertrophy, hyperplasia, and neoplasia (CAG‐TCP). Detailed NOAEL and LOAEL values were derived for each substance, highlighting differences between current findings and previous assessments. The analysis reveals uncertainties due to variations in data quality and study durations. Overall, the report provides a comprehensive hazard characterization of substances affecting thyroid function, contributing to cumulative risk assessment update for effects on the thyroid.