National Toxicology Program

National Toxicology Program

Adverse Outcome Pathways: From Research to Regulation

Workshop graphic with images representing in vitro tests and protecting human health September 3-5, 2014
William H. Natcher Conference Center
National Institutes of Health
Bethesda, Maryland, USA

Workshop report: Kleinstreuer NC, Sullivan K, Allen D, Edwards S, Mendrick DL, Embry M, Matheson J, Rowlands JC, Munn S, Maull E, Casey W. 2016. Adverse Outcome Pathways: From Research to Regulation. Scientific workshop report. Reg Toxicol Pharmacol 76:39-50.

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Videocasts of Workshop Plenary Sessions on NIH Website

  • Day 1 (Wednesday, Sept. 3; 6 hr 28 min)
  • Day 2 (Wednesday, Sept. 4; 3 hr 25 min)
  • Day 3 (Wednesday, Sept. 5; 2 hr 12 min)

Summaries of Breakout Group Discussions


Read article summarizing the workshop in NIEHS Environmental Factor newsletter (October 2014)

Federal Register notice announcing workshop (June 25, 2014) — View as webpage

The traditional model of toxicology testing, which involves treating animals with test substances and observing outcomes, may not be sufficient to serve future scientific and regulatory needs. The science of toxicology is turning towards a new model based on a better understanding of toxicity mechanisms, which will enable prediction of toxic effects in humans.

A key element of a mechanistic understanding of a specific toxicity is the construction of an adverse outcome pathway for that toxicity. An adverse outcome pathway is a conceptual framework constructed from existing knowledge that relates exposure of a type of toxic substance to subsequent molecular and cellular changes that result in illness or injury to an individual or population.

Effective communication between researchers and regulators is a critical determinant of whether new methods or approaches are efficiently translated from the scientific bench to regulatory decision-making practice. This workshop brought together over 100 scientists from industry, academia, U.S. and international regulatory agencies, and animal welfare groups to explore how scientific progress in adverse outcome pathway concepts can improve regulatory assessment of chemical toxicity.

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.