Green Chemistry

Overview of the GC Approach

Twelve guiding principles of GC were proposed in 1998 by Paul Anastas and John C. Warner, by which to assess the greenness of a chemical, a reaction, or a process. The tenets are (1) it is better to prevent waste or pollution than to have to remediate; (2) design synthetic methods to maximize the use of inputs (atom economy); (3) minimize both the use of toxic materials and the production of toxic products and by-products; (4) minimize the use of solvents or other auxiliary agents, or when these are essential to process, the most innocuous substances should be used; (5) minimize energy use (i.e., operate at ambient temperature and air pressure); (6) use renewable inputs whenever practicable and economically feasible; (7) avoid the use of derivative methods; (8) use catalytic rather than stoichiometric reagents; (9) constantly monitor for and proactively control the production of hazardous substances; (10) design with accident and incident prevention in mind; (11) product design should provide both effectiveness and minimized toxicity; and (12) product design should ensure innocuous degradation so that constituents will not accumulate in the environment.

Together, the 12 principles constitute the goal of GC: the design, manufacture, and use of chemical products to intentionally reduce or eliminate hazards and waste. A key approach to this goal is to prioritize the use of renewable and reusable materials, including agricultural waste and biomass as primary starting blocks. Chemical reactions with these materials are typically less hazardous than when conducted with petroleum products. Other principles focus on prevention of wastes, use of less potentially toxic chemical syntheses, and designing safer end products, including safer solvents. Today, many plastic products are made from plant sugars and renewable crops like corn, potatoes, and sugar beets instead of nonrenewable petroleum products. Unlike petroleum-based plastics, they are also biodegradable.

...