"ACToR, a free database from the National Center for Computational Toxicology of the Environmental Protection Agency, compiles quantitative and qualitative information on pesticides, industrial chemicals, water contaminants, and other potentially toxic compounds from a growing list of more than 200 Data Collections from state, federal, and international agencies, academic institutions, and commercial sources. The database is so comprehensive that a new user should visit the Basic Information and Help links found in the home page's left column. The home page displays a brief description and a search box for chemical name or CAS registry number. Results are rapidly displayed on the same page in a table showing structures, chemical names, CAS numbers, the presence of up to seven types of toxicity for each compound or substance returned, and the Generic Chemical Details link, where any information from the Data Collections on a specific substance or compound resides in a fixed set of clearly labeled links. Unfortunately, one must open each link to determine whether it contains any information; however, that is a minor nuisance in a database of this scope.

The easy-to-use Search by Structure link in the left column is designed to allow structure-function investigations of compounds with similar chemical structures. Browse Assays links to assays by phenotype and category as defined in the Help glossary, either with brief details and a citation to complete information or with a Link Out to an external Web site with the information. The Data Collections link alphabetically lists individual data collections, each with further links to content details." Choice, September 2009.