YAHSGS' Toxicological Evaluation Neuralnet Tools (TEND is designed to advance the state-of-the-art in the prediction of toxicological end points for new or untested chemicals, drugs, and compounds. TENT deploys computational neural nets (CNN), innovative computational chemistry methods, and modem statistical regression methods into interactive modules that determine (a) a chemical's 3-D structure and physical chemistry properties, (b) Quantitative Structure Activity Relationships, (C) mechanistic modes leading to toxicological responses via microassay database analysis, and (d) a broad spectrum of toxicological properties via CNN 3-D structural similarity analyses. TENTs output includes physical chemistry properties, 3-D structure, predicted toxicological impacts, and confidence level associated with each. It is anticipated that TENT will become one of the primary tools used by (a) researchers in human health and toxicological fields, (b) pharmaceutical companies to screen out drugs early in the development process prior to expending hundreds of millions on clinical in vivo and in vitro testing, (C) by companies developing new chemicals, chemical compounds, and chemically treated materials to determine potential toxicological impacts including those caused by environmental changes during and after usage, (d) companies striving to show compliance with ISO 14000 for materials used in their products, and (e) federal and military organizations for chemicals and materials contemplated for use in their mission areas. Industry experts predict that the market for TENT-type tools and applications will reach $8 -$10 billion by 2006 and three times that amount by 2016. The benefits that the US should receive from TENT could include (a) a greatly enhanced understanding of potential toxicological impacts from pharmaceuticals, chemicals, and chemically treated materials (4 out of 5 chemicals in industrial use currently have not undergone adequate testing due to time and expense), (b) companies will avoid billions of dollars in clinical testing for chemicals and drugs that ultimately fail (the funds saved can be applied to the development of new and better materials that help mankind and the environment that might otherwise go unfunded), and (c) TENT can substantially reduce the number of laboratory animals used for clinical testing.