Joseph V. Rodricks was a founding principal of ENVIRON International, a consultancy firm focussed on public health and regulatory issues involving substances in the environment. He served as principal scientist at ENVIRON for 35 years, before moving to Ramboll, a Danish consulting firm, until his retirement in 2024. Prior to his work at ENVIRON, he served for 15 years as a scientist at the USFDA, including 5 years as Associate FDA Commissioner for Health Affairs. He has more than 150 scientific publications and has received honorary awards from four professional societies for his contributions to toxicology and risk analysis, and he has served on close to 40 expert committees of the National Academy of Sciences. Harvey J. Clewell has more than 50 years of experience in environmental exposure assessment, toxicology research, chemical risk assessment and hazardous materials management. He gained an international reputation for his pioneering work on the incorporation of mechanistic information and dose-response modeling into chemical risk assessments, having played a key role in the first applications of these approaches by regulatory agencies. He has served on many peer review panels for regulatory agencies in both the US and the EU. He is a recipient of the Society of Toxicology's Arnold J. Lehman Award for major contributions to chemical safety and risk assessment.