Overview
The Principles of Green Chemistry (see Anastas and Warner, Green Chemistry Theory and Practice, Oxford University Press, 1998) were created from a diverse set of practices and research that focused on reducing hazards and impacts at the design and process level when practicing chemical research and development. The set of principles encompass a holistic approach to thinking about how chemists approach their work. Each of the principles are not meant to be used in isolation – but, rather the collection of principles together guide chemists towards best practices in reducing hazards and impacts of their trade. The twelve principles are listed below.
Figure developed by MilliporeSigma and available through the GCTLC library here.
1 Prevent Waste
It is better to prevent waste than to treat or clean up waste after it is formed.
For some examples and educational resources, please see:
- ACS GCI module on alcohols - https://www.acs.org/greenchemistry/students-educators/learning-modules/alcohols.html
- ACS GCI module on solvent selection for SN1 and SN2 reactions - https://www.acs.org/greenchemistry/students-educators/learning-modules/sni-and-sn2-reactions.html
- ACS GCI module on ideal gases and the anthropogenic N2 cycle - https://www.acs.org/greenchemistry/students-educators/learning-modules/ideal-gases.html
- A greener tetraphenylporphyrin synthesis and metallation: an undergraduate teaching experiment - https://doi.org/10.1080/17518253.2022.2164700
2 Atom Economy
Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.
For some examples and educational resources, please see:
- Synthesis of substituted N-phenylmaleimides and use in a Diels–Alder reaction: a green multi-step synthesis for an undergraduate organic chemistry laboratory - https://doi.org/10.1080/17518253.2019.1609596
- Using systems thinking to connect green principles and United Nations Sustainable Development Goals in a reaction stoichiometry module - https://doi.org/10.1080/17518253.2023.2185109
3 Less Hazardous Synthesis
Wherever practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment.
For some examples and educational resources, please see:
- Putting the squeeze on imine synthesis: citrus juice as a reaction medium in the introductory organic laboratory - https://doi.org/10.1080/17518253.2023.2185107
- Wolff–Kishner reduction reactions using a solar irradiation heat source and a green solvent system - https://doi.org/10.1080/17518253.2014.966866
4 Safer Chemicals
Chemical products should be designed to preserve efficacy of function while reducing toxicity.
For some examples and educational resources, please see:
- A Green(er) Redox Reaction - https://gctlc.org/greener-redox-reaction
- The safer chemical design game. Gamification of green chemistry and safer chemical design concepts for high school and undergraduate students - https://doi.org/10.1080/17518253.2018.1434566
- A greener organic chemistry experiment: reduction of citronellal to citronellol using poly(methylhydro)siloxane - https://doi.org/10.1080/17518250802512475
5 Safer Solvents and Auxiliaries
The use of auxiliary substances (e.g. solvents, separation agents, etc.) should be made unnecessary wherever possible and, innocuous when used.
For some examples and educational resources, please see:
- ACS GCI module on solvent selection for SN1 and SN2 reactions - https://www.acs.org/greenchemistry/students-educators/learning-modules/sni-and-sn2-reactions.html
- Synthesis of Schiff's bases in aqueous medium: a green alternative approach with effective mass yield and high reaction rates - https://doi.org/10.1080/17518251003716550
- A greener tetraphenylporphyrin synthesis and metallation: an undergraduate teaching experiment - https://doi.org/10.1080/17518253.2022.2164700
- Extraction of dyes contained in glow sticks using liquid CO2 - https://doi.org/10.1080/17518253.2019.1609594
6 Energy Efficiency
Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic methods should be conducted at ambient temperature and pressure.
For some examples and educational resources, please see:
- "Greening up" the Suzuki reaction - https://gctlc.org/greening-suzuki-reaction
- Synthesis of substituted N-phenylmaleimides and use in a Diels–Alder reaction: a green multi-step synthesis for an undergraduate organic chemistry laboratory - https://doi.org/10.1080/17518253.2019.1609596
- A greener tetraphenylporphyrin synthesis and metallation: an undergraduate teaching experiment - https://doi.org/10.1080/17518253.2022.2164700
7 Renewable Feedstocks
A raw material of feedstock should be renewable rather than depleting wherever technically and economically practicable.
- ACS GCI module on Hydrocarbons; Fuels and Feedstocks: Hydrocarbons and Functional Groups: Connecting Structure to Application in Transportation Fuels - https://www.acs.org/greenchemistry/students-educators/learning-modules/hydrocarbons-fuels-and-feedstocks.html
- ACS GCI module on solvent selection for SN1 and SN2 reactions - https://www.acs.org/greenchemistry/students-educators/learning-modules/sni-and-sn2-reactions.html
- ACS GCI module on ideal gases and the anthropogenic N2 cycle - https://www.acs.org/greenchemistry/students-educators/learning-modules/ideal-gases.html
8 Reduce Derivatives
Unnecessary derivatization (blocking group, protection/deprotection, and temporary modification of physical/chemical processes) should be avoided whenever possible.
9 Catalysis
Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
For some examples and educational resources, please see:
- Re-casting traditional organic experiments into green guided-inquiry based experiments: student perceptions - https://doi.org/10.1080/17518253.2019.1609598
- Iodination of vanillin and subsequent Suzuki-Miyaura coupling: two-step synthetic sequence teaching green chemistry principles - https://doi.org/10.1080/17518253.2019.1609603
- "Greening up" the Suzuki reaction - https://gctlc.org/greening-suzuki-reaction
10 Design for Degradation
Chemical products should be designed so that at the end of their function they do not persist in the environment and break down into innocuous degradation products.
For some examples and educational resources, please see:
- Environmental Fate, Persistence, and Biodegradation (Toxicology for Chemists - Module 7) - https://doi.org/10.59877/EIRU9831
11 Real-Time Analysis for Pollution Prevention
Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.
For some examples and educational resources, please see:
- Water Depollution Control: A Gateway to Reaction Monitoring and Analytical Chemistry - https://pubs.acs.org/doi/10.1021/acs.jchemed.1c00572
12 Inherently Safer Chemistry for Accident Prevention
Substances and the form of a substance used in a chemical process should be chosen so as to minimize the potential for chemical accidents, including releases, explosions, and fires.
For some examples and educational resources, please see:
- ACS GCI module on ideal gases and the anthropogenic N2 cycle - https://www.acs.org/greenchemistry/students-educators/learning-modules/ideal-gases.html