The working definition of green chemistry is the invention, design and application of chemical products and processes to reduce or eliminate the use and generation of hazardous substances.
The Environmental Protection Agency (EPA) first developed green chemistry in reaction to the Pollution Prevention Act of 1990. This act established a national policy to prevent or reduce pollution at its source whenever possible and to devise creative strategies to protect human health and the environment. The original program provided grants for research projects that worked on these topics. In 1993, the program broadened to include topics such as greener solvents and safer chemical alternatives. It was renamed the Green Chemistry Program and coordinated efforts of academia, industry, government agencies and nongovernmental organizations. It promotes the use of chemistry to prevent pollution through voluntary, nonregulatory partnerships.
The green chemistry concept is based on 12 principles developed by the EPA’s Paul Anastas and John C. Warner. These principles explain what the definition of green chemistry means in practice. The 12 principles are as follows:
1. Prevent waste. Design ways to use chemicals to prevent waste. No waste means no need to treat or clean up.
2. Design safer chemicals and products. Ideally, these products would be fully effective and have little or no toxicity.
3. Design less hazardous chemical processes. Design ways to use substances that use and produce chemicals with little or no toxicity.
4. Use renewable resources. Use raw materials and resources that are renewable rather than depleting. Renewable resources often will come from agricultural products or perhaps are waste products from other processes. Depleting resources are those whose source can be used up.
5. Use catalysts to complete chemical reactions. Waste can be minimized by using catalysts or chemicals that are used in small amounts and can be used many times. Other types of reagents work in only one reaction.
6. Avoid chemical derivatives. By keeping a chemical reaction as simple as possible, the amount of waste generated can be minimized.
7. Maximize chemical economy. Using chemical reactions in which the final product contains the greatest amount of the starting materials will decrease the amount of chemicals wasted in the process.
8. Use safer solvents and reaction conditions. The use of solvents, separation agents or other extra chemicals should be avoided. If they must be used, the safest chemicals should be chosen.
9. Increase energy efficiency. Chemical reactions should be run at room temperature and pressure when possible.
10. Design chemicals and products to degrade after use. Chemicals that are designed to break down to harmless substances after use will prevent harmful chemicals from building up in the environment.
11. Analyze in real time to prevent -pollution. Real-time monitoring and control of chemical reactions can minimize or eliminate the formation of byproducts that must be disposed of later.
12. Minimize the potential for accidents. Design chemicals and the form they take (solid, liquid, gas) to minimize the potential for chemical accidents, such as fires, explosions and releases to the environment.
These principles indicate areas that need attention when making and using chemicals in the workplace and help to illustrate that green chemistry isn’t a particular set of technologies, but an emphasis on the design of chemical products and processes. The intent is to help reduce the risk of chemicals and chemical processes on people and their environment. Green chemistry, as stated in the principles, looks at the hazards of the chemical process as a whole, not just at any undesirable substances that may be produced in their use.
Two terms are used repeatedly in the discussion of green chemistry: risk and hazard. These terms inextricably are tied to one another. It often is said that risk is the product of hazard and exposure. Often, when looking to reduce the risk of an occurrence, the most direct way is by reducing the exposure to the threat. This also is true for chemistry and the use of chemicals on the job site. Regulations often require increases in control and treatment technologies and in personal protective equipment (PPE), such as respirators and gloves, to reduce the risk by limiting exposure. While PPE can reduce an employee’s risk, the cost of PPE and the potential for failure of equipment or it being used incorrectly, or not at all, always is a concern.
Green chemistry tries to reduce risk by reducing the hazard associated with the use of chemicals. It’s a way of dealing with risk reduction by decreasing the intrinsic hazards of the substances that are used at a job site. There is no need to worry about exposure if the chemicals that are being used don’t have any hazards associated with them.
Using green chemistry can help protect many aspects of a company’s life. The employees using green chemicals are safer and potentially healthier while making the planet a safer place to live and reducing the address effects on generations to come.
KELLY is a safety and health specialist with Intec, a safety consulting, training and publishing firm that offers on-site assistance and produces manuals, training videos and software for contractors. She can be reached at 800.745.4818 and firstname.lastname@example.org. Joe O’Connor edited this article.