12 Principles of Green Chemistry

Green chemistry is an essential concept for biodesign, biomimicry and the creation of a more viable human presence on Earth. Green chemistry is a field of science that focuses on the design and development of chemical processes and products that minimise the use and generation of hazardous substances. It aims to promote sustainability, reduce environmental impact, and improve the overall efficiency of chemical processes. The 12 principles of green chemistry, which Anastas and Warner first formalised in their 1998 book Green Chemistry, Theory and Practice, provide a valuable framework for guiding researchers, engineers, chemists and innovators in the pursuit of greener and more sustainable chemical practices¹.

1. Waste Prevention

First, do no harm. Think of this as the Hippocratic oath of chemistry. It is better to prevent waste generation than to treat or clean up waste after it is created. This principle emphasises the importance of designing chemical processes that produce minimal waste and are inherently safe.

2. Atom Economy

If you’re hosting a dinner party, you wouldn’t want to throw away half the ingredients during the process of making the meals (unless you’re a bad cook, I guess). Metaphors aside, chemical reactions should be designed to maximise the incorporation of all reactants into the final product, minimising the formation of by-products. This principle promotes the efficient use of raw materials and reduces the generation of waste. For more info, check out this paper².

3. Less Hazardous Chemical Syntheses

Synthetic methods should be designed to minimise or eliminate the use of hazardous substances. This principle encourages the use of safer reagents and solvents, as well as the development of alternative synthetic routes. Usually, it’s not that this is particularly difficult to do. It’s more so that people are more focused on new pathways (hello there, novel IP) rather than what goes in the flask.

4. Designing Safer Chemicals

Chemical products should be designed to have minimal toxicity while maintaining their desired functionality. Easier said than done, though. This principle emphasises the importance of considering the potential environmental and human health impacts of chemicals throughout their life cycle. To achieve this goal, a strong understanding of toxicology and environmental science is needed. In other words, wide boundary thinking is useful to ensure unwanted adverse effects.

5. Safer Solvents and Auxiliaries

The use of auxiliary substances such as solvents should be minimised or replaced with safer alternatives whenever possible. This principle promotes the use of environmentally friendly solvents and other auxiliary agents. Again, relatively straightforward, but time, money and effort tend to hamper this playing out in real-world applications. According to the American Chemistry Society:

‘We will always need solvents, and with many things in chemical processes, it’s a matter of impact trading. The object is to choose solvents that make sense chemically, reduce the energy requirements, have the least toxicity, have the fewest life cycle environmental impacts and don’t have major safety impacts.’

6. Design for Energy Efficiency

Despite what you may think, the energy requirements of a reaction have environmental and economic implications. Energy is and will continue to be a vital issue for the 21st century³⁴. Which is why it doesn’t really make sense to conduct crazy chemical reactions at high temperatures or pressures. As noted by Janine Benyus, Nature’s chemistry is conducted at ambient in ambient conditions⁵. Using biomimetic principles, synthetic chemical processes should be designed to maximise energy efficiency. This principle encourages the development of energy-efficient reactions and separation techniques, as well as the use of renewable energy sources⁶.

7. Use of Renewable Feedstocks

Whenever possible, renewable raw materials and feedstocks should be used in chemical synthesis. This principle promotes the use of biomass, agricultural waste, and other sustainable sources of chemicals. Again, this one kind of just makes sense when you think about it. In nature, there is no waste. All biomass is constantly cycled through the web of life, contributing to the continual regeneration of life.

8. Reduce Derivatives

Unnecessary derivatisation steps (use of blocking groups, protection/deprotection, temporary modification of physical/chemical processes) should be avoided in chemical synthesis. This principle encourages chemists to minimise the number of synthetic steps required to produce a desired compound, reducing waste and improving efficiency.

9. Catalysis

Catalytic reagents should be used in preference to stoichiometric reagents, whenever possible. A catalyst defined as a substance that changes the velocity of a reaction without itself being consumed or changed in the process and can be used many times. Stoichiometric reagents, on the other hand, are consumed during the reaction. Catalysis allows for the use of smaller amounts of reactive substances to be used in a reaction, leading to reduced waste generation and increased reaction efficiency. #Reduce #Reuse #Recycle

10. Design for Degradation

Chemical products should be designed so that they break down into innocuous substances after fulfilling their intended function. This principle promotes the development of environmentally friendly materials that do not persist or accumulate in the environment… A prime example of how not to design for degradation would be plastics and PFAS. A prime example of how to design for degradation would be Fungi Solutions, Great Wrap and our very own Alt.Leather!

11. Real-time Analysis for Pollution Prevention

Analytical methodologies should be developed to allow for real-time, in-process monitoring and control of chemical reactions. This principle enables researchers to detect and address potential environmental and safety issues promptly.

12. Safer Chemistry for Accident Prevention

Substances and processes should be designed to minimise the risk of accidents, including releases, explosions, and fires. This principle emphasises the importance of designing chemical processes with inherent safety features.

These 12 principles provide a roadmap for scientists, engineers, and chemists to develop more sustainable and environmentally friendly chemical processes and products. By doing our best to adhere to these principles, researchers can contribute to the advancement of green chemistry and the transition toward a more sustainable and environmentally conscious society.

Interested to see some green chemistry R&D in action? Be sure to check out our member Alt Leather, one of our alumni, Great Wrap, and our collaborators and good friends over at Fungi Solutions.

References

1. Anastas, P. T. & Warner, J. C. Green Chemistry: Theory and Practice. (Oxford University Press, 2000).
2. Trost, B. M. Atom economy—A challenge for organic synthesis: Homogeneous catalysis leads the way. Angew. Chem. Int. Ed Engl. 34, 259–281 (1995).
3. Hagens, N. & White, D. J. Reality Blind. (2021).
4. Hagens, N. J. Economics for the future – Beyond the superorganism. Ecol. Econ. 169, 106520 (2020).
5. Benyus, J. M. Biomimicry: Innovation inspired by Nature. (Harper-Collins, 1999).
6. Gorissen, L. Building the Future of Innovation on millions of years of Natural Intelligence. (Studio Transitio, 2022).