Green chemistry

Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the designing of products and processes that minimize the use and generation of hazardous substances. Whereas environmental chemistry focuses on the effects of polluting chemicals on nature, green chemistry focuses on technological approaches to preventing pollution and reducing consumption of nonrenewable resources.

The overarching goals of green chemistry—namely, more resource-efficient and inherently safer design of molecules, materials, products, and processes—can be pursued in a wide range of contexts.

How can scientists and industry create the chemicals of the future without replicating the mistakes of the past?

According to Paul Anastas, who wrote the book that defined the field, "The twelve principles of green chemistry are very much common sense. The only problem is that common sense wasn't very common in the way we manufactured chemicals for the last 200 years."

A philosophy, rather than a specific discipline, green chemistry aims to make chemistry both environmentally and financially sustainable.

The principles cover such concepts as:

the design of processes to maximize the amount of raw material that ends up in the product;the use of renewable material feedstocks and energy sources;the use of safe, environmentally benign substances, including solvents, whenever possible;the design of energy efficient processes;avoiding the production of waste, which is viewed as the ideal form of waste management.

The twelve principles of green chemistry are:

It is better to prevent waste than to treat or clean up waste after it is formed.Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.Wherever practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment.Chemical products should be designed to preserve efficacy of function while reducing toxicity.The use of auxiliary substances (e.g. solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic methods should be conducted at ambient temperature and pressure.A raw material or feedstock should be renewable rather than depleting wherever technically and economically practicable.Reduce derivatives – Unnecessary derivatization (blocking group, protection/deprotection, temporary modification) should be avoided whenever possible.Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.Chemical products should be designed so that at the end of their function they do not persist in the environment and break down into innocuous degradation products.Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.Substances and the form of a substance used in a chemical process should be chosen to minimize potential for chemical accidents, including releases, explosions, and fires.