Green Chemistry: Definition & Principles of Green Chemistry

Dear Friends,                   

                    This week I am going to write about the hot and very popular topic of "Green Chemistry". It is the need of hour to switch to green chemistry and green synthesis as these will definitely help in conserving our environment and also will serve to optimize the process of synthesis and its output.

The definition of green chemistry can be simply given as:  "The use of chemical products and processes that reduce or eliminate substances hazardous to human health or the environment”. Or "Green chemistry is the design, development, and implementation of chemical products and processes to reduce or eliminate the use and generation of substances hazardous to human health and the environment." 

Green Chemistry Principles

1.  Prevention

–        It is better to prevent waste than to treat or clean up waste after it has been created.

2.   Atom economy

–        Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.

3.   Less hazardous chemical syntheses

–        Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.

4.  Designing safer chemicals

–        Chemical products should be designed to effect their desired function while minimizing their toxicity.

5.   Safer solvents and auxiliaries

–        The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.

6.   Design for energy efficiency

–        Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.

7.  Use of renewable resources

8.  Reduce derivatives

9.  Catalysis

–        Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.

10.  Biodegradability

11.  ‘Real-time -analysis’ for pollution prevention

–        Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.

12.  Inherently safer chemistry for accident prevention 

Green chemistry principles have an influence on the work of every chemist! 

The role of catalysts is critical:

A good catalyst fulfils also the criteria of points 1-3 and 5-8