About Tox21

The Toxicology in the 21st Century (Tox21) program is a federal collaboration among NIH’s NCATS and the National Toxicology Program at the National Institute of Environmental Health Sciences; the Environmental Protection Agency; and the Food and Drug Administration. Tox21 researchers aim to develop better toxicity assessment methods to quickly and efficiently test whether certain chemical compounds have the potential to disrupt processes in the human body that may lead to negative health effects. Learn more about the goals of the Tox21 program.

Using the Center’s high-throughput robotic screening system, NCATS scientists are testing a collection of 10,000 environmental chemicals and approved drugs (called the Tox21 10K library) for their potential to disrupt biological pathways that may result in toxicity. The team prioritizes promising compounds identified from primary screening for further in-depth investigation. Learn more about how the Tox21 program works.

Tox21 History

Since Tox21’s inception in 2008, the collaborative research team has developed and validated in vitro cell-based assays (tests) using quantitative high-throughput screening. The researchers have identified, developed, optimized and screened more than 100 assays (tests).

The Tox21 program includes three research phases, structured with guidance from two reports — Toxicology in the 21st Century: The Role of the National Toxicology Program and Toxicity Testing in the 21st Century: A Vision and a Strategy (PDF - 418KB) — and The US Federal Tox21 Program: A Strategic and Operational Plan for Continued Leadership.