This datafile is an integration of three existing EPA datafiles, AQUIRE, Phytotox, and Terretox. It includes toxicity data, derived predominantly from the peer-reviewed literature, for aquatic organisms, terrestrial plants and wildlife species, respectively. Each Ecotox test record contains information about the chemical, organism, exposure condition and observed effect under which the toxicity test was conducted. AQUIRE (Acquatic Toxicity Information Retrieval) developed in 1981 through efforts at the U.S.Environmental Protection Agency (EPA) Mid-Continent Ecology Division in Duluth, MN (MED-Duluth), is a comprehensive summary of available aquatic toxicity data. Currently, AQUIRE includes more than 140,000 toxic effect records for 5,900 chemicals and 2,900 freshwater and marine organisms abstracted from more than 10,000 publications. AQUIRE includes lethal, sublethal, and residue effects data for a single-chemical exposures conducted in a field or laboratory setting through the first quarter of publication year 1996. AQUIRE does not include in vitro exposures, mixture and effluent exposures, or sediment exposures that do not report water concentrations. Phytotox, developed through efforts at the U.S. EPA, NHEERL, Western Ecology Division, (WED) in Corvalis, OR, is a database of toxic effects records for terrestrial vascular wild plant species (native or introduced) or agricultural species. Phytotox includes lethal and sublethal effect data through publication year 1991, but does not include results from residue studies. Currently, the database contains more than 48,000 effect records for 900 species and 1,500 chemicals, extracted from 2,600 publications. Terretox (Terrestrial Toxicity Database) was also developed through efforts at the WED, and includes toxicity data for wildlife species. Lethal, sublethal and residues effects data through publication year 1992 are included in Terretox. Terretox currently includes more than 38,000 data records for 240 species and 1,056 chemicals, abstracted from 529 publications. Ecotox also includes the Office of Pesticide Programs (OPP) Ecological Effects Database, which contains toxic effects data categorized as acceptable for fulfillment of pesticide registration and re-registration guideline requirements as explained under FIFRA Subdivision E, Parts 158.145 and 158.150.