Exploration of CFCs
In her organic chemistry class, Becca Horwitz ('18), explored the history and effects of the chemical compounds chlorofluorocarbons.
The sun is shining as you walk down the street in the middle of the summer without sunscreen! You make it inside the air-conditioned building, successfully avoiding a sunburn. This ability to avoid skin damage from the sun’s ultraviolet light is thanks to the ozone layer in the Earth’s atmosphere. The refrigerated building that saved you from the burning sun is functioning due to a man-made chemical compound that poses no immediate, serious threat to humans.
In the early 1900s a team of scientists developed a compound called a Chlorofluorocarbon (CFCs), a non-toxic, non-flammable and low energy refrigerant that gained widespread popularity as a mechanism in new refrigerators and air-conditioners. The very low reactivity of the CFCs allowed them to be used for purposes other than cooling, like propellants in aerosols, since they would not react with the other chemicals in the food, beauty or safety products.
CFCs are also incredibly inexpensive to manufacture and since money runs many aspects of politics, the economic benefits of CFCs dominated policy talks. When it was found in the early 1970s that CFCs are an “Oxygen Depleting Substance” (ODS) no government restrictions were put on the production of CFCs due to the “lack of scientific research” on the negative effects of these chemicals. The economic benefit from producing the very cheap CFC compound allowed the US chemical industry to control the governmental decisions surrounding their production (“Chlorofluorocarbons and Ozone Depletion,” 2017). It wasn’t until a documented hole was found in the ozone layer over Antarctica that policy changes occured. In 1985, 196 countries signed the Montreal Agreement, requiring countries who signed the Agreement to lower their ODS use (“CFC Substitutes,” 2012).
The first alternative developed to CFCs were hydrofluorocarbons (HFCs) which did not deplete the ozone layer. They are more expensive to produce, but their non-reactivity and non-toxicity allowed them to be a viable substitute. There are many different types of HFCs, but certain HFC compounds do have very negative effects on the environment. Many HFCs are over-saturated and “long living” molecules meaning because they are so stable, they can take up to fifty years to decompose. As they decompose, these HFCs live in the lower levels of the earth’s atmosphere. While they do not deplete levels of the atmosphere, they cause a greenhouse gas effect more than 4000 times stronger than the effect of carbon dioxide. There are HFC’s that are not “long living” and use of these HFCs are encouraged by the EPA and other international environmental organizations (“CFC Substitutes,” 2012).
Another alternative to CFCs are hydrofluoroolefins (HFOs.) HFOs are very similar to HFCs but they are unsaturated meaning they have “at least one double bond” (“HFO Refrigerants,” 2015). This factor is important because while they are still relatively unreactive, they are more reactive than HFCs. Their increased (relatively) reactivity is important because these HFOs decompose in a matter of weeks instead of years. This makes their effect on global warming significantly less. A downside to HFOs is that they are also slightly more flammable than most other alternatives (“HFO Refrigerants,” 2015).
Perfluorocarbons are another alternative to CFCs. They are very stable, inflammable and non-toxic, but they have extremely terrible impacts on the environment. They can stay in the atmosphere for thousands of years and their Greenhouse Gas effect is 5000-10000 stronger than that of carbon dioxide (“Perfluorocarbons,” SEPA).
There is a long way to go before the refrigerants we use have no negative impacts on the environment. While the Montreal Agreement allowed the ozone layer to begin repairing itself, many financially challenged countries still use CFCs. In order to make the expensive change from ODS to more sustainable chemicals, financial support to underdeveloped countries is necessary. The United States contributed significantly to this international “Multilateral Fund,” and is due to contribute again. The Trump administration has made no comment about continuing the United States’ involvement in the fund (Leahy, 2017). Hopefully, the Trump administration will decide to keep the financial contributions by the United States and continue the long lasting movement to transition to more sustainable refrigerants and propellants for the better of their country and the world.
CFC substitutes: Good for the ozone layer, bad for climate? (2012, February 24). Retrieved
February 26, 2018, from https://www.sciencedaily.com/releases/2012/02/120224110737.htm
Chlorofluorocarbons and Ozone Depletion. (2017, April 18). Retrieved February 26, 2018, from
HFO refrigerants explained. (2015, October 31). Retrieved February 26, 2018, from
Leahy, S. (2017, September 25). Without the Ozone Treaty Youd Get Sunburned in 5 Minutes.
Retrieved February 26, 2018, from https://news.nationalgeographic.com/2017/09/montreal-protocol-ozone-treaty-30-climate-change-hcfs-hfcs/
Perfluorocarbons (PFCs). (n.d.). Retrieved February 26, 2018, from