Published on July 3rd, 2009 | by Reenita Malhotra0
Green Chemistry – Science for a Less Polluted Lifestyle
Our daily lives are filled with products and chemicals that we have grown accustomed to using on a daily basis. However, may of these are filed with toxic substances that can make us sick both in the short term and in the longer term. Since we use these products all the time, it is sometimes difficult to understand which are safe to use. Green chemistry is a field of study that specifically helps address this situation.
What is Green Chemistry?
The Environmental Protection Agency (EPA) defines green chemistry, or sustainable chemistry, as the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. The use and production of these chemicals may involve reduced waste products, non-toxic components, and improved efficiency.
Whereas environmental chemistry is the chemistry of the natural environment, and of pollutant chemicals in nature, green chemistry specifically seeks to reduce and prevent pollution at its source. Green chemistry applies across the life cycle, including the design, manufacture, and use of a chemical product.
Evolution of Green Chemistry
In 1990 the Pollution Prevention Act was passed in the United States. This act helped create a modus operandi for dealing with pollution in an original and innovative way. It aims to avoid problems before they happen.
Paul Anastas, is known as the “Father of Green Chemistry,” having coined the term in 1991. He is currently the director of Yale’s Center for Green Chemistry & Green Engineering, where his research focuses on the design of safer chemicals and chemical processes to replace the use of hazardous substances. Before this, Anastas was the chief of the Industrial Chemistry Branch and director of the U.S. Green Chemistry Program at the Environmental Protection Agency (EPA).
Since it has a wide range of applications, green chemists research green chemistry technologies across a variety of industries to come up with safe solutions that can be applied to the development of industrial procedures that affect our daily lives.
Green chemistry technologies provide a number of benefits, including:
* reduced waste, eliminating costly end-of-the-pipe treatments
* safer products
* reduced use of energy and resources
* improved competitiveness of chemical manufacturers and their customers.
Green chemistry provides an especially effective approach to pollution prevention because it applies innovative scientific solutions to real-world environmental situations.
Twelve Principles of Green Chemistry
Paul Anastas and John Warner have developed “12 Principles of Green Chemistry”, in Green Chemistry: Theory and Practice which provide a road map for chemists to implement green chemistry. Here is an outline of the twelve principles:
- Prevent waste: Design chemical syntheses to prevent waste, leaving no waste to treat or clean up.
- Design safer chemicals and products: Design chemical products to be fully effective, yet have little or no toxicity.
- Design less hazardous chemical syntheses: Design syntheses to use and generate substances with little or no toxicity to humans and the environment.
- Use renewable feedstocks: Use raw materials and feedstocks that are renewable rather than depleting. Renewable feedstocks are often made from agricultural products or are the wastes of other processes; depleting feedstocks are made from fossil fuels (petroleum, natural gas, or coal) or are mined.
- Use catalysts, not stoichiometric reagents: Minimize waste by using catalytic reactions. Catalysts are used in small amounts and can carry out a single reaction many times. They are preferable to stoichiometric reagents, which are used in excess and work only once.
- Avoid chemical derivatives: Avoid using blocking or protecting groups or any temporary modifications if possible. Derivatives use additional reagents and generate waste.
- Maximize atom economy: Design syntheses so that the final product contains the maximum proportion of the starting materials. There should be few, if any, wasted atoms.
- Use safer solvents and reaction conditions: Avoid using solvents, separation agents, or other auxiliary chemicals. If these chemicals are necessary, use innocuous chemicals.
- Increase energy efficiency: Run chemical reactions at ambient temperature and pressure whenever possible.
- Design chemicals and products to degrade after use: Design chemical products to break down to innocuous substances after use so that they do not accumulate in the environment.
- Analyze in real time to prevent pollution: Include in-process real-time monitoring and control during syntheses to minimize or eliminate the formation of byproducts.
- Minimize the potential for accidents: Design chemicals and their forms (solid, liquid, or gas) to minimize the potential for chemical accidents including explosions, fires, and releases to the environment.
Read more about green chemistry at Yale University’s Center for Green Chemistry and Green Engineering.