The Toxicity of Lead and Lead‐Free Perovskite Precursors and Nanocrystals to Human Cells and Aquatic Organisms

displays a notably safer environmental impact profile at elevated concentrations, while Pb and Bi exhibit dose-dependent toxicity. This study provides compelling evidence that Sn compounds demonstrate a safer toxicity profile in both human cells and aquatic organisms under the studied conditions, supporting their potential as a more environmentally friendly alternative. In contrast, Bi compounds exhibit a toxicity profile similar to Pb perovskites, warranting caution in its use as a substitute. These findings guide future research and regulatory efforts in the safety and sustainability of perovskite nanocrystals.