Dr. Chad M. Thompson is a Managing Scientist with the Center for 21st Century Toxicology and holds a doctoral degree in Biomedical Sciences. Dr. Thompson specializes in mechanistic and quantitative aspects of risk assessment. He has written extensively on the mode of action (MOA) of high-profile compounds such as formaldehyde, hexavalent chromium, and dioxin. He has also helped design, conduct, and analyze multimillion-dollar research projects with a focus on understanding the toxicity of environmental contaminants and application of such information to risk assessment. Dr. Thompson has extensive experience in dose-response modeling (including benchmark dose modeling), and he helped develop dose-response packages for the R statistical language (www.r-project.org). Dr. Thompson specializes in the integration of dose-response, toxicological, and mechanistic information in human health risk assessment. As a former health scientist at the U.S. Environmental Protection Agency (EPA), he is a co-author of multiple IRIS chemical risk assessments, as well as several agency documents on risk assessment practices and policies, including the application of physiologically based pharmacokinetic (PBPK) models, toxicogenomic data, and lifestage susceptibility information in risk assessment. Dr. Thompson is a coauthor of more than 50 publications in the peer-reviewed literature, many of which pertain directly to human health risk assessment. He is a former Risk Policy Fellow with the American Association for the Advancement of Science (AAAS).