By Tommy Doc – Updated Mar 24, 2022
Image credit: Grassetto/iStock/GettyImages
Chlorofluorocarbons (CFCs) are synthetic compounds composed of chlorine, fluorine, and carbon. Their release into the atmosphere is particularly harmful because they destroy ozone molecules, which shield the planet from harmful ultraviolet radiation. Since 1995, the vast majority of countries have phased out CFC production, yet a handful of niche products still contain them.
The leading CFC emitters are refrigerants, followed by aircraft fire‑suppression systems and aerosol propellants.
Refrigerants, especially those introduced after the 1930s, remain the most common source of atmospheric CFCs. Brands like DuPont’s “Freon” sparked a global adoption of CFC‑based coolants. Improper disposal or leaks from older refrigerators, vehicles, and HVAC units allow CFCs to evaporate into the air or seep into soil, ultimately reaching the upper atmosphere.
Many aviation authorities still mandate the use of Halon— a CFC‑derived gas— for onboard fire suppression. As of 2011, no fully safe, equally effective substitute has been adopted worldwide. The industry must therefore adhere to stringent handling, storage, and recycling protocols to mitigate environmental risk.
Aerosol cans historically relied on CFCs as propellants. The transition to hydrocarbon alternatives began in 1999, but legacy CFC molecules persist in the stratosphere for 20 to 100 years, continuing to contribute to ozone depletion.
Outdated refrigeration units and aerosol containers often go unnoticed, leaking CFCs into the atmosphere. Researchers at the University of East Anglia are developing techniques to trace these local emissions. By sampling stratospheric air and analyzing it with mass spectrometry, they can pinpoint specific sources—such as old CFC refrigerators— and inform targeted cleanup efforts.
