Traditionally chemical engineers have been more concerned about selectivity than conversion. Green technologies explore alternate reaction conditions, alternate (solvent free) media and even alternate energy sources. Green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is the most fundamental approach to pollution prevention. Green chemistry addresses the need to produce the goods and services that society depends on in a more environmentally benign manner. Life-saving pharmaceuticals can be produced while minimizing the amount of waste generated, plastics that biodegrade can be synthesized from plants, and reactions can be run in water rather than in traditional organic solvents by applying green chemistry principles to chemical products and processes.