Citation:

Description:

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.

Record Details:

Record Type:MODEL

Product Published Date:10/29/2003

Record Last Revised:11/16/2009

Record ID: 74887

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Model Detail:

Model Evaluation :Model validation for mode of action expert system and available QSAR models are provided in the publication:
Russom, C.L., Bradbury, S.P., Broderius, S.J., Hammermeister, D.E., and Drummond, R.A. 1997. Predicting modes of toxic action from chemical structure: Acute toxicity in the fathead minnow (Pimephales promelas). Environ. Tox. Chem. 16(5):948–967.

ASTER includes links to the homepage for third-party applications (ClogP, KowWin, and BioWin), providing an overview of model validation and related citations.

Model URL :http://www.epa.gov/med/Prods_Pubs/aster.htm

Model Guidance Documents :User guide can be downloaded from the website http://www.epa.gov/med/Prods_Pubs/aster.htm

Model Decision Documents :Help center has content specific help on:

• how to move throughout the site
• single vs. multiple chemical searches
• report format options
• codes / overview of each data field output from ASTER

Site includes linkages to supporting documentation such as:

• SMILES tutorial
• codes used within the ECOTOX data output
• coding guidelines for the ECOTOX data
• procedures used in verifying chemical information
• linkages to other resources that may be of use to ASTER users

Model Download Information :Application is a web-based expert system and models cannot be downloaded from system.

modelcontactinfo :Christine L. Russom
USEPA/ORD/NHEERL/MED
Russom.chris@epa.gov
218-529-5218
The model was developed by U.S. EPA, Office of Research and Development (ORD), National Health and Environmental Effects Research Laboratory (NHEERL), Mid-Continent Ecology Division (MED)-Duluth MN.

Model Inputs :Models require a structure. There is a database of over 56,000 structures associated with ASTER, and if a user enters a CAS number or chemical name the system will search for a structure. If not located, user will be prompted that not all models will work without structure information. Users can enter structure via SMILES notation.

Model Outputs :Output is either to a web-viewable report format with text, and tables; or an MS Excel format. Full citations are provided for any models / data cited within the report. Uncertainty associated with models is provided. Users can look at the details of how a value was estimated / predicted; and override any property / value that is used in the final report during the active session.

Model Computer Requirements:

Model Operating Systems Needs :Microsoft Windows 98, 2000, XP, NT4

Model Hardware Needs :Desktop PC

Model Programming Language(s) :Model on mainframe and/or workstation(s), but remotely accessible through the EPA intranet. The program runs on a server that is located in and is only accessible from MED LAN. It is not open to the outside and no URL address is provided.

The model includes access to third-party software (ClogP) and other applications built through Cooperative agreements (BOD model and Cancer Model).

The model has two external supporting databases: (1) ECOTOX database provides empirical aquatic toxicity test data (publicly available at www.epa.gov/ecotox) and (2) EcoChem provides measured physical/chemical property information (not available via intranet or internet).

other_req :Web browser; IE version 5.0 or higher User must have access to EPA’s Intranet