Green Chemistry and its Role in Environmental Protection
Green chemistry is the design of chemical products and processes that minimize or eliminate the use or generation of substances hazardous to human health, animals, plants or the environment. It is a broader term than "sustainable chemistry" and includes a range of approaches that address environmental, energy, and societal concerns.
The Environmental Protection Agency (EPA) and Green Chemistry
The Environmental Protection Agency (EPA) is one of the leading authorities on green chemistry and has published many technical guides to help researchers identify alternative chemicals and processes that are safer for the environment. The EPA and the American Chemical Society (ACS) have also collaborated to develop educational materials on green chemistry including case studies and laboratory modules that are aimed at undergraduate and graduate students. The ACS has also revised several of its existing materials to include the concept of green chemistry.
The Importance of Green Chemistry
Increasingly, scientists are concerned about the environmental impacts of their synthesis methods and products. This concern has led to the development of new methods for reducing wastes, minimizing energy consumption, and using more bio-based feedstocks. The emergence of green chemistry has been an important contribution to these efforts by enabling the development of chemical processes that can more efficiently utilize resources while generating products that are safer for humans, animals and the environment.
As a result, the field of green chemistry has grown significantly over the last decade or so and has been recognized by prestigious organizations such as the National Academy of Sciences and the International Union of Pure and Applied Chemistry. Young scientists are encouraged to apply for PhosAgro/UNESCO/IUPAC research grants in green chemistry and to contribute their ideas towards greener synthesis practices.
Reducing Wastes: Solvent Alternatives in Chemical Production
Oftentimes, the most significant waste generated in chemical production is that of solvents, which are used for dissolving reactants and extracting and washing products, separating mixtures, cleaning reaction apparati, and dispersing products. Although these solvents are not integral parts of the compounds undergoing reaction, they are highly toxic, and their presence in a synthesis can dramatically increase the overall pollution footprint of a process or product.
Various cleaner solvents have been evaluated as replacements for these traditional auxiliary agents, which are now known to be problematic for the environment and human health. To assist chemists in identifying alternatives, the Massachusetts Institute of Technology has developed a "Green Alternatives Wizard" that is based on the 12 Principles of Green Chemistry and can be used as a tool for selecting solvents.
This ranking method can be used to evaluate any chemical or chemical process that uses the 12 principles of green chemistry, as well as to compare alternatives. It is a comprehensive, transparent, efficient, and quantitative method for assessing the performance of any chemical or process compared to the alternatives on all 12 principles.
The method combines the availability of readily available information with a comprehensive and transparent approach to evaluating green chemistry in a way that complements the widely accepted Life Cycle Assessment (LCA) approach. By utilizing the data from the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) and standardized boundaries, this approach can score all of the 12 principles simultaneously and transparently.
