Chemical Safety Sciences

Our Mission

Develop toxicity testing strategies, dose response modeling methods, and quantitative analytical tools to increase the accuracy and decrease uncertainties in chemical safety assessments.


Melvin Andersen, Ph.D., leads The Hamner Program in Chemical Safety Sciences and is a Hamner Senior Investigator and Director of the Divisions of Computational Biology and Translational Biology. For the past 4 years he was Director of The Hamner Long-Range Research Initiative supported by the American Chemistry Council. During his 35- year career in toxicology and risk assessment, Dr. Andersen has developed biologically realistic models pertaining to the uptake, distribution, metabolism, and biological effects of toxic chemicals and drugs, and applied these models to safety evaluations and quantitative health risk assessments. His research has pioneered new uses of pharmacokinetic and mechanistic data in federal risk assessment programs. In 2002, Dr. Andersen was recognized as a 'highly cited' scientist by the Institute for Scientific Information. Dr. Andersen has served on numerous committees and advisory boards, including the Committee on Toxicity Testing and Assessment of Environmental Agents at the U.S. National Academy of Sciences (NAS), the Advisory Board for the Center for Alternatives to Animal Testing, and the Executive Committee, Board of Scientific Counselors for the U.S. Environmental Protection Agency's Office of Research and Development.

The Changing Landscape

Chemical safety sciences have reached a tipping point. The 2007 NAS report, Toxicity Testing in the 21st Century, sees a future in which toxicity testing will be conducted in human cells or cell lines by evaluating perturbations of cellular responses in a suite of toxicity pathway assays using high-throughput robotic-assisted methodologies. Dose response modeling requires computational systems models of the circuitry underlying the toxicity pathways. In vitro to in vivo extrapolations rely on pharmacokinetic models to relate the concentrations at which effects are seen in the in vitro assays to anticipated human exposures. These new approaches will use fewer animals, improve knowledge of modes of action, enhance human relevance, provide higher chemical throughput than is possible with current toxicity testing strategies focused on high dose studies in live animals, and significantly improve product stewardship and responsible care efforts.

Research Strategy

The Hamner Program in Chemical Safety Sciences is committed to conducting key mechanistic and computational research to accelerate implementation of the new NAS report. The report provides the opportunity for an important paradigm shift in toxicity testing and chemical safety sciences. However, dose response and in vitro to in vivo extrapolation tools need to be developed alongside the in vitro toxicity pathway tests to ensure the wise use of these data in the risk assessment process. Multi-faceted research approaches will be pursued at The Hamner using prototype compounds to illustrate how risk assessments can be improved by application of these alternative in vitro methods.


Toxicity Testing in the 21st Century: A Vision and a Strategy

This report was authored by the Committee on Toxicity Testing and Assessment of Environmental Agents and published by The National Academies of Sciences in 2007.

Centers of Excellence