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Assessment Tools for the Evaluation of Risk
ASTER (Assessment Tools for the Evaluation of Risk) was developed by the U.S. EPA Mid-Continent Ecology Division, Duluth, MN to assist regulators in performing ecological risk assessments. ASTER is an integration of the ECOTOXicology Database (ECOTOX; www.epa.gov/ecotox) and QSAR (Quantitative Structure Activity Relationships), a structure activity based expert system. ASTER is designed to provide high quality data for discrete chemicals, when available in the associated databases and QSAR-based estimates when data are lacking. The QSAR system includes a database of measured physicochemical properties such as melting point, boiling point, vapor pressure, and water solubility as well as more than 56,000 molecular structures stored as SMILES (Simplified Molecular Input Line Entry System) strings for specific chemicals. ECOTOX is a comprehensive database, which provides information on adverse effects of single chemical stressors to ecologically relevant aquatic and terrestrial species. ECOTOX includes more than 500,000 test records covering more than 6,000 aquatic and terrestrial species and 10,000 chemicals.