Structure-activity relationships for selecting and setting priorities for existing chemicals - a computer-assisted approach.

The incorporation of structure-activity relationships and other estimation methods in a computer format is a logical and necessary step in handling the complex problem of setting priorities for existing chemicals in a feasible, systematic way. In combination with an appropriate hazard ranking methodology, the computer format is a useful tool for selecting existing chemicals for further testing and more detailed assessment. Recent developments and applications of a proposed system for setting priorities for existing chemicals are discussed, along with the system's expected reliability and limitations. Important gaps that now exist in our understanding of the relationships between structure and physiochemical and toxicological properties, as well as reactivities, are pointed out. Selected chemicals are cited in examples of the application of the new computer-assisted methodology. (IUCT)