In the present day we constantly come across the word ‘green’ in every field and aspect. Naturally the word green is associated with environment or eco friendly. In the same way green chemistry is also linked with environment but it has broader meanings.
WHAT IS GREEN CHEMISTRY ?
Green chemistry is not a different branch of chemistry but it is the greener approach of conventional chemistry. It focuses on minimum use and reduction of hazardous substances and by- products in industry or labs. With the increasing impact of industries on environment due to increase in levels of green house gases, ozone layer depletion and pollution. It encourages sustainable development. The Environment Protection Act (EPA) agency gave 12 principles to guide the chemical industries. These principles were given by Paul Anastas of the EPA agency.
- To prevent waste rather than to treat it.
- Synthetic materials should be designed to maximize the incorporation of materials to increase the yield.
- To minimize the production of hazardous products so that it should not affect the workers.
- Designing safer chemicals especially in drugs.
- The energy requirement for the reaction should be kept minimum.
- Selection of more appropriate and greener solvents.
- Choice of starting materials.
- Use of protecting groups in chemical reactions.
- Use of catalyst to increase the rate of reaction.
- Products designed should be biodegradable.
- Manufacturing plants should be designed such that to eliminate the possibility of accidents during operation.
- Strengthening of analytical techniques so that there is minimum usage of chemicals, recycling of unreacted reagents.
Even though all these principles appear to be simple and have greener approach but implementing these rules is still a big question. Scientists have developed many greener methods for many reactions. Implementing these principles requires investment, time and redesigning of inexpensive processes. Greener methods are more expensive and difficult to apply. The criticism is that whether any greener method can be sealed up to industries in large scale. A solution to this can be development of green methods in the viewpoint of industrial use rather than laboratory techniques.