Environmental performance metrics for daily use in synthetic chemistry.

A simple quantitative approach to enable chemists to compare alternative chemical syntheses on the lab bench with respect to their resource usage and their potential environmental impact is proposed; this may be useful for the systematic design of more sustainable processes. We consider as metrics the mass index S(-1) and the environmental factor E to characterize quantitatively the reaction input and output, respectively. The potential environmental impact is estimated by using easily available data of each compound of the feed and of each compound of the waste. The calculations can easily be performed using EATOS-environmental assessment tool for organic syntheses.