Assessing Toxic Risk is a comprehensive guide to student research in toxicology. It includes an overview of basic principles of toxicology and how they are used to assess chemical risks. It provides simple but authentic research protocols to engage students in the process of testing chemical toxicity by conducting bioassays using lettuce seeds, duckweed, and Daphnia. It also contains guidelines for integrating peer review and other collaborative knowledge-building into classroom science. Toxicology makes an ideal topic for student research because it provides a natural link between biology, chemistry, environmental science, and human health; it highlights the connections between science and public policy; and builds critical-thinking skills.