ECOSAR program

The ECOSAR program is used to predict the aquatic toxicity of chemicals based on their similarity of structure to chemicals for which the aquatic toxicity has been previously measured. Since 1981, the USEPA has used (Q)SARs to predict the aquatic toxicity of all new industrial chemicals (Nabholz et al. 1993 Zeeman et al. 1995). The acute toxicity of a chemical to fish (both fresh- and saltwater), water fleas... 

Integrating concentration- and effect-addition principles with (Q)SAR opens the door for (Q)SAR-based mixture assessments. As discussed above, linking interspecies correlations (Asfaw et al. 2004) with the USEPA s ECOSAR program allowed for the generation of species sensitivity distributions, hence a probabilistic estimate for aquatic community effects. Estimated HC5s for 4 chemicals were within a factor of 2 of published values, suggesting that current uncertainty factors overestimate NOECs established via data-based SSDs even SSDs derived... 

The OPPT uses the ECOSAR program to calculate the acute and chronic toxicity of chemicals to aquatic species. ECOSAR contains over 150 SARs that have been developed for more than 50 chemical classes. Most SAR calculations in the ECOSAR program are based upon log Kow alone. Various surfactant SAR calculations are based on the average length of carbon chains or the number of ethoxylate units. A summary of the endpoints covered is provided in Table 19.3 and more details may be obtained from the OPPT SAR manual (Clements, 1996). A useful assessment of the applicability of ECOSAR has been made recently (Hulzebos and Posthumus, 2003). 

Table 19.3 Major Toxicity End Points Predicted by the ECOSAR Program... 

United States Environmental Protection Agency (2011) Methodology document for the ecological Structure-Activity Relationship Model (ECOSAR) Class Program MS-Windows Version 1.1 Office of Pollution Prevention and Toxics, Washington, DC. http //www.epa.gov/ oppt/newchems/tools/ecosartechfinal.pdf. Accessed 09 Mar 2012... 

The US EPA Ecological Structure Activity Relationships (ECOSAR ) Class Program estimates the aquatic toxicity of industrial chemicals, in particular... 

This chapter is dedicated to the memory of Vince (J. Vincent) Nabholz, who died suddenly on February 23, 2008. He was a graduate of Christian Brothers University, received a PhD from the University of Georgia, and was senior biologist and ecologist with the US Environmental Protection Agency in Washington, DC, where he served for 29 years, and where he chaired their Structure-Activity Team for the last two decades. He was the principal author of USEPA s ECOSAR computer program, which also is one of the three key elements in Persistence Bioaccumulation Toxicity (PBT), one of the most frequently used (Q)SAR tools of all time. 

Meyland WM, Howard PH. 1998. User s guide for the ECOSAR class program. North Syracuse (NY) USEPA. 

Ecological Structure-Activity Relationships (ECOSAR) This model is used to predict aquatic toxicity, an increasingly important component of the EPA risk assessment program. The EPA has a large information database for chemicals that have been the subject of PMN, but for which the PMN was submitted as confidential business information (CBI). This represents just one example where relying on the model alone will not predict the EPA s response to the submission. 

ECOSAR (EPA, 1994) is a computer program for estimating the ecotoxicity of industrial chemicals. 

ECOSAR Ecological Structure Activity Relationships (ECOSAR)—a computer prediction system for assessing the aquatic toxicity of industrial compounds. It was developed in 1979 by US EPA. The program is based on the SAR calculates acute and chronic toxicity for aqueous organisms (fish, aquatic invertebrates and plants) http //www.epa.gov/oppt/newchems/tools/21ecosar.htm... 

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