Green chemistry is revolutionising the way we approach sustainability in science. Rachel Sully explores its 12 guiding principles – from waste prevention to energy efficiency – and gives tips on how to implement these in your own laboratories.
Sustainability and eco-friendly practices in chemistry and science are crucial for protecting natural resources, reducing environmental harm, and ensuring a healthier, more resilient future for both the planet and future generations. One way to enhance sustainability in the laboratory is by implementing the principles of Green Chemistry.
Green chemistry is defined by the International Union of Pure and Applied Chemistry (IUPAC) as “the invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances”. Applying green chemistry across the lifecycle of a chemical product – including its design, manufacture, use and ultimate disposal – helps reduce the pollution from the chemical product at its source.
Green chemistry does not focus on the cleanup of pollution, rather it tackles the source by preventing the hazardous materials from being generated in the first place. It serves as a philosophy that can be applied to all areas of chemistry, instead of being confined to a single discipline. This focuses on applying innovative scientific solutions to real-world environmental problems, leading to source reduction by preventing the generation of pollution. It seeks to reduce the negative impacts of chemical products and processes on human health and the environment.
There are 12 principles that can be implemented to help make a laboratory sustainable and green:
- Prevent waste: This is the principle that, by minimising the amount of waste gener ated during reactions, we can avoid having to manage waste treatment or clean-up. Using readily available tools such as E-factor and process mass intensity can help reduce the amount of waste produced and therefore make a reaction greener.
- Maximise atom economy: Atom economy is calculated similarly to yield – the molecular weight of the desired product is divided b y the molecular weight of all the reagents – and gives a more useful look at how the starting reagents can be incorporated into the final product to reduce waste.
- Less hazardous chemical syntheses: Using greener alternative selection guides to design protocols that use and generate substances with little to no toxicity to humans or the environment. Using fewer toxic materials reduces the generation of hazardous waste.
- Design safer chemicals: This principle involves utilising knowledge of how chemicals are metabolised in the body and their fate in the environment to reduce their impact.
- Safer solvents and auxiliaries: Many solvents and auxiliary substances end up as waste to chemical processes. By minimising the use of solvents and auxiliary substances, impacts from the beginning of the life cycle of a chemical process can be minimised and waste prevented. If solvents or auxiliary substances must be used, then safer ones should be considered.
- Minimise energy use: This principle is simple – minimise energy use in all parts of the chemical process. This can be achieved by running experiments at ambient temperatures and pressures.
- Renewable feedstocks: Use starting materials that are renewable instead of depletable. New processes and chemistries are being developed that create chemicals from renewable feedstocks, such as algae and sugar cane.
- Reduce chemical derivatives: This principle involves minimising the use of additional materials during a chemical process, for example avoiding the creation of derivatives and use of protecting groups.
- Use catalysts: Catalysts enable reactions to be carried out under lower temperatures, as well as allowing selective modification and can reduce the number of steps in a reaction, all of which increase the atom economy of a reaction and therefore generate less waste.
- Design for degradation: Make sure that the products you are designing degrade readily and do not accumulate in the environment.
- Real-time monitoring to prevent pollution: Include in-process, real-time monitoring and control during syntheses to minimise or eliminate the formation of byproducts.
- Accident prevention: Design experiments that use and generate substances that have the lowest health, safety and environmental impacts to reduce the risk of accidental exposure, in turn preventing waste.
Implementing green chemistry principles can range from straightforward to complex, depending on the specific laboratory, industry and processes involved. A wide range of industries from manufacturing and agriculture to pharmaceuticals and energy, are implementing the green chemistry principles. Examples of companies implementing changes include IKEA and Pfizer.
IKEA is transitioning from fossil-based to bio-based glues in its board production to reduce its climate footprint. The company aims to decrease fossil-based glue use b y 40% and greenhouse gas emissions from glue by 30% by FY30. This initiative follows over a decade of research and trials to find sustainable alternatives.
Pfizer significantly improved its manufacturing process for sertraline hydrochloride (the active ingredient in Zoloft) by applying green chemistry principles. The new process doubled overall product yield, reduced raw material use by 20-60%, eliminated approximately 1.8 million pounds of hazardous materials and enhanced worker safety.
The pharmaceutical industry contributes majorly to waste and hazardous byproducts. Implementing green chemistry techniques in pharmaceutical labs reduces the use of toxic reagents and solvents. Another way to increase sustainability during production is by using biocatalysts over traditional chemical catalysts. Moving away from traditional pesticides and fertilisers in agriculture can reduce their environmental impacts. For example, biodegradable pesticides that break down into harmless substances, and slow-release fertilisers that minimise run-off.
Advancing renewable energy technologies relies on sustainable chemical processes – examples include using biofuels as a greener alternative to fossil fuels, as they rely on renewable feedstocks and reduce greenhouse gas emissions.
Implementing green chemistry principles can range from straightforward to complex, depending on the specific laboratory, industry and processes involved
There are many benefits to green chemistry, including environmental protection, improved health and safety, economic advantages and compliance with regulations. However, there are still many challenges to overcome. Significant investment in research, development and infrastructure is required to transition from traditional processes to greener alternatives. Developing alternative processes and materials that are both environmentally friendly and effective can be technically demanding. Inconsistent regulations and a lack of supportive policies can impede the adoption of green chemistry – without clear guidelines and incentives, industries might lack the motivation to implement sustainable practices. There is often a lack of awareness and understanding of green chemistry principles – integr ating green chemistry into educational curricula and professional training is essential to overcome this barrier. Establishing a reliable supply chain for green materials and building the necessary infrastructure for sustainable processes can be challenging.
Although there are challenges associated with implementing green chemistry principles, small changes can have a significant impact. Here are some easy-to-implement tips to get you started:
- Don’t forget about your fumehood: Typically, ventilation systems use the most energy in the lab, thus closing fumehood sashes can help. The higher the sash of a fumehood the more energy required; therefore, closing the sash, even if only stepping away temporarily, can help reduce energy consumption.
- Keep time: Running equipment less often decreases energy consumption. For example, running an autoclave only twice a day can prevent unnecessary half-filled cycles, reducing the number of times a day it is used and therefore lowering the energy it consumes.
- Running freezers at too low temperatures: Raising a freezer from -80°C to -70°C can save 30-40% energy while still being cold enough to preserve samples. l Switching to glassware: reducing waste by eliminating single-use plastics can improve general waste disposal and recycling.
References:
IUPAC, Sustainable Chemistry, https://iupac.org/who-we-are/committees/sustainablechemistry/#:~:text=Green%20chemistry%20is%20 defined%20by,hazardous%20 substances%E2%80%9D%20 (Pure%20Appl Accessed 02 February 2025
Beyond Benign and My Green Lab 2020, A Guide to Green Chemistry Experiments for Undergraduate Organic Chemistry Labs, Version 2 (2020), https://www.mygreenlab.org/ uploads/2/1/9/4/21945752/gc_-_green_chem_guide-_ beyond_benign___my_ green_lab.pdf. Accessed 02 February 2025
Ikea 2023, Ikea to use Bio-Based Glue for Reduced Climate Footprint (2023), https://www.ikea.com/global/en/newsroom/sustainability/ ikea-to-use-bio-basedglue-for-reduced-climatefootprint-230301/. Accessed 02 February 2025
EPA 2024, Presidential Green Chemistry Challenge: 2002 Greener Synthetic Pathways Award (2024), https://www.epa.gov/greenchemistry/presidentialgreen- chemistrychallenge-2002-greenersynthetic-pathways-award. Accessed 02 February 2025
