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Toxicity Testing in the 21st Century: A Vision and a Strategy
  • Daniel Krewski, University of Ottawa
  • Daniel Acosta, Jr, University of Cincinnati
  • Melvin Anderson, Hamner Institutes for Health Sciences
  • Henry Anderson, Wisconsin Division of Public Health
  • John C. Bailar, III, University of Chicago
  • Kim Boekelheide, Brown University
  • Robert Brent, Thomas Jefferson University
  • Gail Charnley, HealthRisk Strategies
  • Vivian G. Cheung, University of Pennsylvania
  • Sidney Green, Jr, Howard University
  • Karl T. Kelsey, Harvard University
  • Nancy I. Kerkvliet, Oregon State University
  • Abby A. Li, Exponent, Inc.
  • Lawrence McCray, Massachusetts Institute of Technology
  • Otto Meyer, Technical University of Denmark
  • Reid D. Patterson, Reid Patterson Consulting, Inc.
  • William Pennie, Pfizer, Inc.
  • Robert A. Scala, Exxon Biomedical Sciences
  • Gina M. Solomon, Natural Resources Defense Council
  • Martin Stephens, The Humane Society of the United States
  • James Yager, Johns Hopkins University
  • Lauren Zeise, California Environmental Protection Agency
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With the release of the landmark report Toxicity Testing in the 21st Century: A Vision and a Strategy, the U.S. National Academy of Sciences, in 2007, precipitated a major change in the way toxicity testing is conducted. It envisions increased efficiency in toxicity testing and decreased animal usage by transitioning from current expensive and lengthy in vivo testing with qualitative endpoints to in vitro toxicity pathway assays on human cells or cell lines using robotic high-throughput screening with mechanistic quantitative parameters. Risk assessment in the exposed human population would focus on avoiding significant perturbations in these toxicity pathways. Computational systems biology models would be implemented to determine the dose-response models of perturbations of pathway function. Extrapolation of in vitro results to in vivo human blood and tissue concentrations would be based on pharmacokinetic models for the given exposure condition. This practice would enhance human relevance of test results, and would cover several test agents, compared to traditional toxicological testing strategies. As all the tools that are necessary to implement the vision are currently available or in an advanced stage of development, the key prerequisites to achieving this paradigm shift are a commitment to change in the scientific community, which could be facilitated by a broad discussion of the vision, and obtaining necessary resources to enhance current knowledge of pathway perturbations and pathway assays in humans and to implement computational systems biology models. Implementation of these strategies would result in a new toxicity testing paradigm firmly based on human biology.

This article is based on the report Toxicity Testing in the 21st Century: A Vision and a Strategy, prepared by the Committee on Toxicity Testing and Assessment of Environmental Agents. The report was originally published by the U.S. National Research Council in 2007.

Citation Information
Krewski, D., Acosta Jr, D., Andersen, M., Anderson, H., Bailar III, J. C., Boekelheide, K., ... & Kelsey, K. T. (2010). Toxicity testing in the 21st century: a vision and a strategy. Journal of Toxicology and Environmental Health, Part B, 13(2-4), 51-138.