The term green chemistry, coined in 1991, is defined as "the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances." This approach to the protection of human health and the environment represents a significant departure from the traditional methods previously used. Although historically societies have tried to minimize exposure to chemicals, green chemistry emphasizes the design and creation of chemicals that are not hazardous to people or the environment. It has been applied to a wide range of industrial and consumer goods, including paints, dyes, fertilizers, pesticides, plastics, medicines, electronics, dry cleaning, energy generation, and water purification.

At the heart of green chemistry is the recognition that hazard is simply another property of a chemical substance. Properties of chemicals are caused by their molecular structure; they can be modified by changing that structure. The types of hazards that can...