Chemical testing can kill thousands of animals per test, including rodents, rabbits, and dogs. However, a new nonanimal testing method could change that.

Tox21 is a robotic system—developed in part by the Environmental Protection Agency, the Food and Drug Administration, and the National Institutes of Health—that can rapidly test thousands of chemicals without the use of animals.  A test chemical is placed on a plate with more than 1,500 wells that hold various types of cells that can be derived from human tissues. The robotic device then scans the cells for biological activity. Computer screens display how the chemical and cells interact and allow scientists to see how the human body would be affected by the chemical.

Tox21 can quickly evaluate the backlog of approximately 80,000 chemicals, something that is simply not feasible with animal testing. For example, a single animal-based reproductive toxicity study requires a minimum of two years, $380,000, and 2,600 animals. Tox21 could do the test in a matter of weeks.

Now in its second phase of testing, Tox21 will evaluate 10,000 chemicals and compare data it collects to existing toxicity information as a test of its accuracy.

Tox21 meets recommendations made by the National Research Council’s Toxicity Testing in the 21st Century: A Vision and a Strategy. This EPA-commissioned report calls for the development of human-based cell and tissue tests to replace animal tests for hazard assessment and chemical regulation.

To learn more about how PCRM scientists are working to ensure that chemical-testing techniques like Tox21—which rely on modern cell-based tests instead of animals—better protect animals and humans, visit ReformToxicityTesting.org.