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Chemical Assessment Clustering Engine (ChemACE)

The Chemical Assessment Clustering Engine (ChemACE)

The U.S. EPA Office of Pollution Prevention and Toxics (OPPT) has extensive experience reviewing chemicals with limited data and routinely uses structure-activity relationship (SAR) techniques to associate untested chemicals to a broader set of similar compounds (analogs) that have existing data from which read across may be applied. Sets of analogous chemicals can be referred to as “clusters” organized on the basis of structural features and a reasonable presumption that toxicity may be influenced by such structural characteristics.

To help facilitate this work, OPPT has developed the Chemical Assessment Clustering Engine (ChemACE) to assist in the review and prioritization of large inventories of structurally diverse chemicals and to help facilitate read across to fill data gaps for untested substances. The ChemACE tool “clusters” all chemicals in a large user defined inventory (using a variation of the Analog Identification Methodology – AIM algorithm) in a single run. This new tool has been shown to be useful for identifying structural diversity in a chemical inventory and instantly highlighting analogous clusters for potential read across. It has been used to successfully organize and cluster over 10,000 test substances within minutes during preliminary testing.

Using the ChemACE Tool

Users should read the ChemACE User's Manual provided within the program to understand the proper use and limitations of ChemACE.  The user must apply professional judgement to determine the adequacy of any resulting clusters developed from ChemACE before read across and data gap filling approaches are applied. The ChemACE User's Manual can be downloaded from the following link: ChemACE User Tutorial (PDF) (45 pp. 592 kb, about PDF) and is also available within the software programs “Help” button on the main data entry page. This file requires the Acrobat Reader.

ChemACE Download and Set-up

The required software is Microsoft Windows 95 or later (including 98, ME, NT, XP, Vista, and Windows 7).  ChemACE operates best on IBM-compatible computers with an 80386, 80486 or more recent processor; 2 MB RAM minimum; at least 30 MB available disk space.

The new ChemACE software is available for free from the EPA Office of Pollution Prevention and Toxics (OPPT). It is posted below as a downloadable software program and does not require a license for installation and use. Download ChemACE by selecting the following link: ChemACEsetup.exe (33MB).  ChemACE is a self-extracting file. Once it is copied to diskette or hard drive, execute (double-click) the file to install the program.

How Can I Obtain Additional Information about ChemACE?

U.S. EPA Technical Contact:
Kendra Moran-Bruce, U.S. EPA
Office of Chemical Safety and Pollution Prevention,
Office of Pollution Prevention and Toxics,
Risk Assessment Division (7403M)
1200 Pennsylvania Ave., N.W.
Washington, DC 20460-0001
Phone: 202-564-4322
e-mail: moran.kendra@epa.gov

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