The 21^st  International Workshop on Quantitative Structure-Activity Relationships (QSAR2025) in Environmental and Health Sciences will gather QSAR developers and users from academia, regulatory agencies, and industry.  This event will serve for exchanging insights and perspectives on emerging research findings, tools, and regulatory applications related to (Q)SARs and data analysis. The workshop will focus on, but is not limited to, the following active research areas:
   
- AI, big data and QSAR
- Implementing and integrating in silico NAMs for regulatory decision-making contexts
- (Q)SARs for screening, prioritization and data gap filling
- In silico approaches for green chemistry, sustainability and climate change
- In silico strategies for data poor endpoints or substances
- Drug design and drug toxicity
- Quantification of data and model uncertainties
- (Q)SARs for toxicokinetic modelling
- Emerging technologies and challenges (e.g. UVCBs, mixtures, nano)
- Methodological aspects of (Q)SARs modelling
- Read-across, grouping, and consensus modelling within a Weight of Evidence framework