Finding Potential Replacements for TRI Solvents Using the Environmental Impact of the Average Solvent.

A solvent has many different types of impact on the environment. This article describes a method that combines several different types of impacts together into one environmental index so that similar solvents may be compared by their cumulative impact to the environment. The software tool PARIS III (Program for Assisting the Replacement of Industrial Solvents III) initially finds thousands of solvents mixtures with behaviors as close as possible to those of the original solvent entered. The overall environmental impacts of these solvent mixtures are estimated and assigned to environmental indexes. Users of the software tool can then choose replacements for the original solvent with similar activities but with significantly smaller environmental indexes. These solvent mixtures may act as practical substitutes for the industrial solvents but substantially reduce the overall environmental impact of the original harmful solvents. Potential replacements like this are found for three of the U.S. Environmental Protection Agency's Toxic Release Inventory solvents, carbon tetrachloride, toluene, and N-methylpyrrolidone.