It is impossible to imagine modern life without the products provided by the petrochemical industry. These products are used in health care, consumer products, transportation, food processing, electronics, and construction. Yet, the same chemical processes that produce materials also generate wastes and emissions. The challenge is to keep the costs of chemical products affordable, while continuing to reduce environmental impacts. Approaches that avoid the generation of wastes or pollutants, variously known as green engineering, environmentally conscious manufacturing, eco-efficient production, or pollution prevention, can provide alternatives that are cost effective and result in significant environmental improvements.