What is the purpose of using computational toxicology and QSAR in risk assessment?

• A. To measure in vivo exposure in humans
• B. To predict toxicity and prioritize testing for new chemicals using structure-activity relationships, reducing animal testing and guiding regulatory decisions.
• C. To replace all regulatory decisions with computer predictions
• D. To eliminate need for safety testing

Answer: (B)

Computational toxicology and QSAR are used to predict how a chemical might cause harm by linking its molecular structure to potential toxic effects. By translating structural features into toxicity estimates through structure–activity relationships, these tools allow rapid screening of many chemicals, helping to prioritize which substances need in vivo testing and what kinds of studies are most informative. This supports regulatory decisions while aiming to reduce animal testing and accelerate risk assessment. Predictions are not a substitute for actual data; they carry uncertainties and are best used within a weight-of-evidence approach, with clear applicability domains and validation. The other options miss the main purpose: in vivo exposure is a different aspect (exposure assessment), and replacing all regulatory decisions or eliminating safety testing would ignore important safeguards and data needs.