This is the first report of the Interagency Toxic Substances Data Committee (ITSDC) on its efforts to coordinate classification, storage, and retrieval of chemical information. Since its inception in 1978, the ITSDC has focused its efforts on the construction of a Chemical Substances Information Network (CSIN). The Chemical Substances Information Network is designed to facilitate efficient and widespread use of many independent sources of chemical information. By providing analytic capabilities and interconnections between various kinds of data, it streamlines collection and integration of information from diverse sources, reducing the time and paperwork required to reach informed decisions about chemical hazards and benefits. CSIN will ultimately contribute to better decisionmaking by all sectors of society as they grapple with the known and unknown risks of chemicals.