ToxCast Enters Second Phase

EPA’s National Center for Computational Toxicology has launched the second phase of its ToxCast program. Begun in 2007, ToxCast aims to predict the toxicity of thousands of chemicals with the help of high-throughput, cell-based assays and computational methods (C&EN, Aug. 13, 2007, page 36). The program has already tested about 300 chemicals, mostly pesticides, during its proof-of-concept phase, using more than 500 fast, automated assays. In the second phase of the program, researchers will screen about 700 additional chemicals, including those found in industrial and consumer products, food additives, and drugs that failed clinical trials because of their toxicity. Several of the new chemicals are significant because they will allow EPA to compare the ToxCast results to human clinical data, not just data from animal toxicology studies. This comparison will allow EPA to determine which ToxCast assays accurately predict human toxicity and disease.