OVERVIEW

Reduced risk of exposure and minimal environmental toxicity are important dimensions of sustainable chemistry. Cradle-to-grave life cycle assessments and fate and transport studies must be employed to quantify potential emissions of chemicals at different life cycle stages, pathways through the environment, and likely exposure concentrations. The safety of chemical processing can be increased through substitution of hazardous/toxic components by less dangerous ones, just-in-time production to minimize transport and storage of unsubstitutable reactants/intermediates, and targeted design based on knowledge of the solubility, mobility and bioavailability of products. Life-cycle thinking often reveals trade-offs between and sometimes even within environmental, social and economic objectives. For example, thin film photovoltaics reduce greenhouse gas (GHG) emissions while consuming some of the earth’s most exotic metal resources. Reducing fossil energy use and acid emissions by light-weighting motor vehicles, using H2 as an alternative fuel, and decreasing the sulfur content of petroleum, requires alloys and catalysts based on cobalt, whose extraction in Central Africa has fueled regional armed conflicts for decades. Understanding the trade-offs between various environmental, social and economic objectives is critical in the sustainable design of materials and products.