Green chemistry or
sustainable chemistry has been defined as the utilization of a set of principles
that reduces or eliminates the use or generation of hazardous substances in the
design, manufacture and application of chemical products as outlined in the
“Twelve Principles of Green Chemistry’ developed by Paul Anastas and John Warner
The 12 principles 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
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
Catalytic reagents (as selective as possible) are superior to
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
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.
Green chemistry aims
at pollution prevention by eliminating or reducing the need for solvents. As a
chemical philosophy, green chemistry applies to organic chemistry, inorganic
chemistry, biochemistry, analytical chemistry, and even physical chemistry.
While green chemistry seems to focus on industrial applications, it does apply
to any chemistry choice. There are two ways, green chemistry can promote
pollution preventions, the first is reducing the need for solvents by
substituting solvents and ingredients, and the second is by reducing energy
needs. Thus the major objective of Green Chemistry is,
To reduced waste, eliminating costly end-of-the-pipe
To produce safer products.
To reduced use of energy and resources .
To improve competitiveness of chemical manufacturers
and their customers.