Green chemistry, also known as sustainable chemistry, is a new and revolutionary way of looking at the synthesis of new chemicals for the purpose of making chemistry more friendly to health and the environment. The basic idea is to ensure that the design and development of new substances, products or materials consider their potential impact on health and the environment and that alternatives are developed to minimize this impact.
This new concept of green chemistry reveals a much kinder side of chemistry, as this novel approach helps conserve and protect resources by cutting down on water and power consumption and reducing the environmental impact of chemicals after use, to obtain benefits that allow a healthier lifestyle and environment.
Although further advances are still needed, this avant-garde perspective has gained strong support from scientists, investors and institutions who assist with its development.
Through molecular-level design and innovation, green chemistry has become a powerful tool that helps REDUCE:
Green chemistry is based on 12 principles originally formulated in the late 1990s by Paul Anastas, of the U.S. Environmental Protection Agency, and John C. Warner in their book Green Chemistry. These principles are as follows:
Preventing waste formation is better than treating or cleaning it up after it is created.
2 Atom economy
Synthetic methods should be designed to maximize incorporation of all materials used in the process into the final product, to minimize the formation of byproducts*.
3 Safe synthesis
Wherever possible, synthetic methods should be designed to use and generate substances with little to no toxicity for humans and the environment.
4 Safer chemicals
Chemicals should be designed to achieve their desired function while minimizing their toxicity.
5 Safer solvents
Auxiliary substances (solvents, separation agents, etc.) should be avoided unless essential and should, at the very least, be harmless.
6 Energy efficiency
Energy requirements should be carefully considered and adjusted to minimize their environmental and economic impact.
7 Renewable feedstocks
Feedstocks should be renewable rather than depletable, whenever technically and economically practicable.
8 Reduce derivatives
Unnecessary generation of derivatives* (blocking groups, protection/deprotection, temporary modification of physical/chemical processes) should be minimized.
Priority should be given to catalysts*, which should be as selective as possible and as reusable as possible, as opposed to stoichiometric reagents*.
Chemicals should be designed to ensure that, when their function is complete, they do not persist in the environment but break down into nonharmful degradation products.
Analytical methodologies should be developed to allow real-time, in-process monitoring and control before byproducts form.
12 Accident prevention
Substances and how they are used in chemical processes should be chosen to minimize accidents.
7 Fontes renováveis.
As matérias-primas devem ser renováveis e não extinguíveis, na medida em que tal seja técnica e economicamente praticável.
8 Evitar derivados.
A formação desnecessária de derivados* (bloqueio de grupos, proteção/desproteção, alteração temporal de processos físicos/químicos) deve ser evitada tanto quanto possível.
Deve ser dada prioridade à utilização de catalisadores*, os quais deverão ser tão seletivos e reutilizáveis quanto possível face aos reagentes estequiométricos*.
Os produtos químicos devem ser concebidos de modo a que, após terem cumprido a sua função, não subsistam no ambiente, devendo fragmentar-se em produtos de degradação inerte
Devem ser desenvolvidos métodos analíticos que permitam o acompanhamento em tempo real, durante o processo, bem como o controlo prévio da formação de substâncias secundárias.
12 Prevenção de acidentes.
As substâncias e as suas formas de utilização nos processos químicos devem ser selecionadas da forma que implique a menor possibilidade de ocorrência de acidentes.