In
1998, Paul Anastas (who then directed the Green Chemistry Program at
the US EPA) and John C. Warner (then of Polaroid Corporation)
published a set of principles to guide the practice of green chemistry.
The
twelve principles address a range of ways to reduce the environmental and
health impacts of chemical production, and also indicate research priorities
for the development of green chemistry technologies.
The
principles cover such concepts as:
·
the design of processes to maximize the amount of the 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:
1.
Prevention.
Preventing waste is better than treating or cleaning up waste after it is
created.
2.
Atom economy. Synthetic
methods should try to maximize the incorporation of all materials used in the
process into the final product.
3.
Less hazardous chemical
syntheses. Synthetic methods should avoid using or
generating substances toxic to humans and/or the environment.
4.
Designing safer chemicals. Chemical
products should be designed to achieve their desired function while being as
non-toxic as possible.
5.
Safer Solvents and auxiliaries.
Auxiliary substances should be avoided wherever possible, and as non-hazardous
as possible when they must be used.
6.
Design for energy efficiency.
Energy requirements should be minimized, and processes should be conducted at
ambient temperature and pressure whenever possible.
7.
Use of renewable feedstocks.
Whenever it is practical to do so, renewable feedstocks or raw materials are
preferable to non-renewable ones.
8.
Reduce derivatives.
Unnecessary generation of derivatives—such as the use of protecting groups—should
be minimized or avoided if possible; such steps require additional reagents and
may generate additional waste.
9.
Catalysis. Catalytic reagents
that can be used in small quantities to repeat a reaction are superior to stoichiometric reagents
(ones that are consumed in a reaction).
10. Design
for degradation. Chemical products should be designed so that they
do not pollute the environment; when their function is complete, they should
break down into non-harmful products.
11. Real-time
analysis for pollution prevention. Analytical
methodologies need to be further developed to permit real-time, in-process
monitoring and control before hazardous substances form.
12. Inherently
safer chemistry for accident prevention. Whenever
possible, the substances in a process and the forms of those substances should be chosen to minimize risks such as explosions, fires, and accidental
releases.
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