Green Chemistry Metrics


Scientific Update LLP, United Kingdom


How far should chemists go when considering the overall environmental impact of their activities? This article discusses green chemistry metrics and also considers aspects such as energy utilisation and packaging materials.

Over the last 25 years attitudes to waste have changed dramatically and Green Chemistry is a fully recognised part of industrial chemistry considerations and also many academic chemists are working on more environmentally friendly methodologies and solvent systems. We now have a series of metrics for measuring the greenness of our chemistry and how we can improve the environmental footprint of our chemistry including atom economy, E-factor and process mass intensity (PMI) to name just a few. In more recent times we have been encouraged to think “globally” about the environmental impact of our activities, and to consider sustainability and not just waste minimisation.

Whenever a new compound comes in to development the first activity is to review the synthetic route and then either change the route altogether, or change one or more of the reagents and/or catalysts and/or solvents used to carry out a particular chemical step. And this is often an iterative process as a project moves through the various stages of development and larger quantities of material need to be produced. We can easily see what the impact is on the efficiency of our synthesis in terms of cost, ec ...