What is the primary role of QSAR in risk assessment?

• A. It predicts toxicity based on chemical structure to prioritize testing and fill data gaps.
• B. It directly measures toxicity in humans.
• C. It reduces the need for any testing entirely.
• D. It provides regulatory guidelines for manufacturing.

Answer: (A)

QSAR in risk assessment is about predicting a chemical’s potential toxicity from its structure, so you can prioritize testing and fill data gaps without immediate experiments. By linking molecular features to known toxic effects from existing data, QSAR provides screening estimates for new or data-poor substances, helping identify which chemicals need further study and how to allocate testing resources. This supports hazard characterization and informs decisions like read-across, while aiming to reduce unnecessary testing. Predictions carry uncertainty and depend on how well the chemical fits the model’s applicability domain, so they are best used alongside other data and evidence. It does not measure toxicity directly in humans, does not fully replace testing, and does not provide regulatory manufacturing guidelines.