Read-across is best described as what?

• A. Generating new animal studies for the target chemical.
• B. Using data from similar chemicals to predict hazards for a chemical with limited data, reducing testing and guiding hazard assessment.
• C. Replacing all data with in silico predictions.
• D. Identifying exposure routes only.

Answer: (B)

Read-across uses toxicity data from structurally or mechanistically similar chemicals to infer hazards for a chemical with limited data. This lets hazard assessment proceed and testing be prioritized or reduced, because similarities in structure, mode of action, or metabolism suggest similar toxic effects. It’s a way to fill data gaps without conducting new experiments, supporting the 3Rs by limiting animal testing and guiding risk assessment. It’s not about generating new animal studies, not about replacing all data with in silico predictions, and it’s not solely about identifying exposure routes; those describe different approaches.