The practice of life cycle assessment has been well documented as a tool for comparing products and processes or comparing various components within a life cycle. This paper addresses the question of how changes can be made once an assessment has been completed, such as identifying the improvements that can be made to address environmental problems and to decrease impacts on human health and the environment. Green chemistry, a fairly recent approach that addresses environmental concerns at a fundamental level, has already demonstrated examples of what we call 'life cycle innovation', that is, improvements at all stages of the product or process life cycle. This paper explores various applications of green chemistry methodologies to all stages of a product or process life cycle.

To meet the goals of sustainability and to enable industrial ecology, green chemistry and engineering needs to be studied from a life-cycle perspective. When designed correctly, green chemistry and engineering can affect multiple stages of the life cycle of a product or process. Successful implementations of green chemistry and engineering research are improving the environmental impacts of chemical products and processes in every stage of the life cycle while also offering economic incentives. Analysis of new and existing green chemistry and engineering technologies with quantitative and qualitative metrics can identify and quantify these benefits. The examples presented illustrate the principles of life-cycle assessment as applied to green chemistry and engineering.