Connor Kabes 1/15/16
The word “green” is a buzzword that has become popular in recent years as consumers demand renewable and environmentally safe products. Much like the phrase “all natural,” “green” has come to mean a variety of things in the world of consumer goods. Likewise, many researchers also describe experimentation as “green.” The royal society of chemistry even publishes a journal called “Green Chemistry.” What exactly is green chemistry?
The Environmental Protection Agency defines a green chemical as one, which, from its inception to disposal, “reduces or eliminates the use or generation of hazardous substances.” Because this definition is so broad, the EPA provides 12 principles, which further define green chemistry. They are as follows:
1) Prevent Waste – Waste is a real issue. Laboratory waste (which is relatively minimal) is often incinerated, like medical waste. Waste from processing of chemical products and metals often results in immense amounts of waste. An excellent example of this is “red mud,” which is a byproduct of aluminum production. Millions of tons of sludge are pumped annually into holding ponds because there is currently no disposal method. Its alkalinity poses an environmental risk.
2) Maximized Atom Economy – This is beneficial to both industry and the environment. When creating new compounds, synthetic routes that provide the least amount of waste should be chosen.
3) Design Less Hazardous Syntheses – There is usually more than one way to accomplish a step in a synthesis. When faced with options, choose the less hazardous route.
4) Design Safer Chemicals – While easier said than done, the safety of a new chemical produced should be thoroughly evaluated.
5) Use Safer Solvents and Reaction Conditions – Choose a route that avoids the use of solvent. When this is not possible, chose the least hazardous solvent.
6) Increase Energy Efficiency – When possible, run reactions at room temperature and at atmospheric pressure.
7) Use Renewable Sources – This is a big one. Many monomers can be produced using biochemical process, which employ the use of bacteria or enzymes to create chemical starting materials without petroleum products. An
example is 1,3-propanediol, which can be made entirely through bacteria.
8) Avoid Chemical Derivatives – The use of protecting groups during synthesis is discouraged because it creates unnecessary waste.
9)Use Catalysts, Not Stoichiometric Reagents – When a reaction can be carried out effectively using catalysts, its produces less waste and makes better use of the atom economy.
10)Design Chemical Products to Degrade – The biodegradation of chemical products should be taken into account, especially when producing new plastics or polymer materials.
11) Analyze Reactions in Real Time – Rather than run chemical tests after a reaction, analyze and modify reaction in real time to prevent hazardous byproducts or unnecessary waste.
12) Minimize the Potential for Accidents – This is a given in any lab or production facility. Chose chemicals which are in a safer form (e.g. solids are safer than liquids) and those which pose a lesser hazard to health and safety.