Any book discussing the history of chemistry will speak of the horrors of the sheer amount of chemical waste that was produced in the early days of the chemical industries. In this innocent age before regulatory agencies, chemical waste was often simply dumped in the closest river, or just buried. It’s not difficult to predict the outcome of such actions, and sure enough, whole communities were decimated; it was largely public clamor that led to the formation of laws to govern the treatment and handling of chemical waste.
Today – even with advanced catalysts and refined syntheses chemical plants produce simply amazing amounts of waste. It is not uncommon to see 20+ pounds of chemical waste be produced per pound of desired chemical product produced. What is this waste? It could be byproducts that appeared somewhere along the synthesis, solvent that either cannot be recycled or is deemed too costly to recycle, impure inorganic salts which are of no practical use and which must be discarded, and the list continues. Since (nowadays) it is very expensive to safely handle and dispose of chemical hazardous waste, the unwanted production of this waste stream is a cost burden for the chemical plant they would rather be without. Everyone would probably agree that this planet would be better off with less chemical waste being generated. So, finding ways to reduce this waste stream would be a win-win situation. Enter green chemistry.
Green chemistry is a philosophy that states that chemical processes should be designed so that hazardous materials are neither used nor generated. In principle that’s a goal that’s hard to reach, but many companies are reaching now toward sustainable chemistry, in which the catalyst or solvent, say, is totally recycled and never leaves the process as chemical waste. The whole idea of green chemistry was designed by Paul Anastas, a fellow at the Environmental Protection Agency in 1998 and outlined in a book. Here are the author’s twelve principles of green chemistry, reworded so as to make more sense to the chemical layman:
1. Design processes that don’t produce waste.
2. Design your companies products to be effective without being toxic.
3. Design your processes so they use less toxic materials.
4. Use starting materials that come from renewable sources like agriculture, instead of nonrenewable sources like petroleum.
5. Use tiny amounts of chemicals to act as catalysts, which can be recycled, instead of huge amounts of chemical additives which then can’t be recycled.
6. As much as possible, have the shortest, simplest chemical process.
7. Don’t waste material make sure all of starting materials end up connected to / part of your product.
8. Try to avoid solvents; if they are necessary, try to use something nontoxic, like water.
9. Don’t waste energy find a way to run your process at room temperature and pressure, instead of having to heat it or pressurize it.
10. Design your products to degrade and break down into innocuous materials after use.
11. Keep a close eye on your process to be alert for the moment byproducts start to form.
12. Minimize the potential for accidents, so that a chemical process doesn’t pose a danger to the workers or to the environment.
All of this is rather common sense, but before heavy fines were levied against polluting chemical companies, the implementation of some of these guidelines just didn’t make monetary sense to the factory owners, as bad as that sounds. Thankfully, we are gradually entering an age where green chemistry not only makes sense on the budget-balance sheet, but is quickly becoming the politic way to present an innocent, caring public face. The world will soon begin to benefit not only from less costly chemical products, but from less chemical pollution as well.