Jun 23 2008
Background
Green Chemistry Principles
Background
Stated most simply, green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Fewer hazardous substances means less hazardous waste and a healthier environment.
Green Chemistry Principles
The 12 principles of green chemistry are:
- 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 A reaction where a substance is used to increase the rate of a chemical reaction, without being consumed or produced by the reaction.. Catalysts are used in small amounts and can carry out a single reaction many times. They are preferable to Refers to compounds or reactions in which the components are in fixed, whole-number ratios. reagents, which are used in excess and work only once.
- Avoid chemical derivatives: Avoid using A removable chemical unit used by synthetic chemists to purposefully cover up certain regions of a molecule so they do not react with other compounds during a reaction. 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 less harmful or dangerous chemicals.
- Increase energy efficiency: Run chemical reactions at background or room 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.
Source: California Department of Toxic Substances Control