Marrying Life Cycle Inventory Data and Green Chemistry Measures to Advance Sustainable Chemicals Production

There are several well-known examples in green chemistry where process changes to improve a target synthesis have induced the use of highly toxic chemicals two or more steps upstream, yet no automated approach has been developed to measure the inherent toxicity of these intermediate chemical inputs.  Here we present a new modeling algorithm adapted from LCA that measures inherent risk (toxicity) of inputs rather than impacts from emissions that occur over the life cycle and applied this algorithm to all organic chemicals in the ecoinvent LCI database.  For each target chemical we have calculated a new metric of ‘life cycle chemical risk’ and compared this to the toxicity of the target chemical itself.  Results show that there is very low correlation (r<0.01) between these sets of values, suggesting that current measures of inherent chemical risk are missing large upstream effects and thus do not provide chemists with adequate design guidance.