Above: Image © Petmal,iStockPhoto.com

Do you recycle? Compost? Turn off the lights when you leave a room? If so, you’re practicing sustainability. In other words, you’re recognizing that our planet has limited resources, and you’re supporting its long-term health.

Historically, when chemists have designed products like plastics, pesticides, and pharmaceuticals, they focused on the product’s usefulness. They didn’t necessarily think about sustainability. In fact, a lot of these products (and the processes used to make them) have actually turned out to be harmful for the environment! That’s why the field of green chemistry has been growing over the past 30 years.

Green chemistry helps chemists look at the sustainability and environmental impacts of man-made chemical products and processes. Green chemists think about a chemical’s impact from the laboratory, to the disposal site, to the environment where it is released. One way they can evaluate these impacts is with the 12 guiding principles of green chemistry. Let’s look at three of these principles in detail.

The Prevention of Waste

This principle actually applies to many aspects of life, both in and outside of the laboratory. For example, it’s the first rule of the three R’s (reduce). It’s important to dispose of waste properly. But it’s even better to reduce the amount of waste in the first place. You might apply this principle at home by trying to produce less garbage. Chemists apply this principle by trying to produce less chemical waste.

You might not think of your car as something that produces waste, but it does. Inside a car’s engine, gasoline, fuel, and oxygen from the air combust. This combustion produces the energy needed for the car to move, but it leads to some harmful byproducts. For example, carbon monoxide is poisonous. Also, volatile organic compounds (VOCs) and nitrogen oxides (NOx) contribute to smog. This can cause respiratory illnesses.

Luckily, cars actually contain a piece of technology that helps with this problem. While the car is running, catalytic converters chemically change these pollutants into less harmful molecules like oxygen (O2), nitrogen (N2), carbon dioxide (CO2), and water (H2O) before they’re released from the tailpipe.

Did you know? Smog is a combination of two words: smoke and fog. This describes what smog looks like!

Atom economy

Imagine you are making cookies and you measure out two cups of flour. But you only end up using one cup of flour to make the cookies, and throw out the other cup. That would be very wasteful!

Sadly, this type of waste can happen when chemists make various products through chemical reactions. Green chemists aim to reduce it by looking at atom economy, the amount of starting material that is converted into the final product.

Ideally, products should have high atom economy. This means that most of the ingredients added during a process are indeed used to make the final product.

Catalytic Ingredients

A catalyst is a substance that helps a chemical reaction happen and makes it go faster. Catalysts can lead to reactions that produce less waste and/or have a greater atom economy.

Take the example of the catalytic converter above. As its name suggests, the converter contains a catalyst. It causes the reaction that converts some of those toxic gases to less harmful ones.

As an added bonus, catalysts aren’t used up in a reaction! That means they can be continually reused without being replaced.

Did you know? In 2001 and 2005, the Nobel prize in chemistry was awarded to chemists that have designed more efficient reactions, an area of green chemistry.

The principles of green chemistry at work

By incorporating green chemistry principles, chemists can make some of the products you use every day less harmful to the environment. Meanwhile, manufacturers can often save money. That’s because green chemistry means more efficient processes with less wasted material, less energy used, and less hazardous waste to clean up!

Did you know? You might have an example of green chemistry in your medicine cabinet: ibuprofen, the active ingredient in Advil and Motrin. The original method for making ibuprofen was wasteful and inefficient. But a new process in the 1990s incorporated the 3 principles you just read about, and earned the company a Presidential Green Chemistry Challenge Award in the United States in 1997.

Green chemistry is part of sustainability. You may not be a green chemist yourself, but you can still apply sustainable practices in your life! For example:

  • Reduce waste
  • Recycle or compost when possible
  • Dispose of harmful waste in the proper way (for example: recycle batteries and electronics at designated locations, and return unused medicine to your pharmacy instead of putting it down the drain)
  • Reduce your energy at home by turning off lights and unplugging electronics when you’re not using them

Finally, you can make a big impact when you go shopping. Buy products that don’t have a lot of packaging, are less harmful to the environment, and are made with sustainability in mind!

Did you know? In Canada, organizations like the Canadian Institute of Canada’s Canadian Green Chemistry and Engineering Network, GreenCentre Canada, and University of Toronto’s Green Chemistry Initiative are part of green chemistry movement in research, industry, and education.

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Learn more!

Green Chemistry: Scientists Devise New "Benign by Design" Drugs, Paints, Pesticides and More (2010) Laber-Warren, Scientific American

What is Green Chemistry? American Chemical Society

Presidential Green Chemistry Challenge: 1997 Greener Synthetic Pathways Award United States Environmental Protection Agency

Rachel Hems

Rachel Hems

Originally from a small town in southern Ontario, called Palgrave, I moved away and studied chemistry at the University of Guelph. After some opportunities to do research as an undergraduate, I found a passion for environmental and analytical chemistry. I am now a PhD candidate in atmospheric chemistry at the University of Toronto, where I study chemical reactions that occur in the atmosphere that relate to climate and human health, and the role that clouds play on the types of reactions that can take place. I am also fascinated by astronomy and try to learn as much as I can about our universe!

Je suis originaire de Palgrave, une petite ville du sud de l’Ontario. Dans le cadre de mon baccalauréat, j’ai pu faire de la recherche en chimie à l’Université de Guelph. Ainsi, j’ai découvert une passion pour la chimie analytique et la chimie de l’environnement. Je suis maintenant en train de faire un doctorat en chimie atmosphérique à l’Université de Toronto. J’étudie des réactions chimiques qui se produisent dans l’atmosphère et qui influencent le climat et la santé humaine. Notamment, j’analyse la façon dont les nuages déterminent les types de réactions qui se produisent. Je suis également captivée par l’astronomie. J’essaie d’en apprendre le plus possible sur l’univers!