R22 is also known as Freon HCFC-22. For decades, it was one of the most important refrigerants used in air conditioning, heat pumps, and refrigeration systems. Its popularity began in the second half of the 20th century when it replaced earlier, more flammable or toxic substances, such as R12.
R22, properly known as dichlorodifluoromethane (HCFC-22), was developed as part of the family of freons – refrigerants produced by the DuPont company, and this was before World War II. This fact alone sparks the imagination and shows what an old invention it was; it was essentially already in use before most of the world's citizens had even heard of heat pumps or air conditioners. It was used, for example, in refrigerators. R22 was intended to replace earlier refrigerants that were flammable or dangerous – mainly the aforementioned R12, because at that stage, humanity truly did not have the choice of refrigerants that it has today. Thanks to its thermodynamic properties, R22 quickly gained recognition in the then-nascent refrigeration industry.
In the 1970s and 1980s, R22 became a global standard. It was relatively cheap, easy to use, had good thermodynamic properties, and a wide range of applications – from domestic air conditioners, refrigerators, and freezers to large industrial installations. At that time, no one expected that this substance would become a symbol of environmental problems – it was precisely during this time that intense research on the ozone layer in the stratosphere was underway, and the concept of the "ozone hole" emerged. What connection does R22 have with this? More on that below.
In the 1970s, scientists discovered that R22 – being a compound from the HCFC group – contributes to the destruction of the ozone layer, i.e., it creates an ozone hole – a thinning of the protective ozone layer in the stratosphere. Its ODP index (Ozone Depletion Potential) was very high in the case of R22.
It was then that the first legal regulations limiting its use appeared. However, no country wanted to phase it out unilaterally – because it would hurt the competitiveness of its own refrigeration industry. The idea became to create a broader agreement in which more countries would impose similar restrictions and implement them around the same time. A key moment was the signing of the Montreal Protocol in 1987, which mandated the gradual phase-out of ozone-depleting substances. This was a death sentence for R22 – albeit a delayed one, as the Montreal Protocol did not require an immediate ban on R22. It was to be phased out over time.
From the 1990s, programs to reduce the production and consumption of R22 began. In the European Union, the use of new R22 in equipment was banned from 2010, and a complete ban on its use, even for servicing existing systems, has been in effect since 2015. Similar regulations were introduced in many other regions of the world. Considering that after 1987, more countries joined the Montreal agreement – eventually encompassing practically the entire world (197 countries) – R22 is now rather dead in a commercial and practical sense. Equipment specifically designed for R22 is no longer produced.
The phase-out of R22 forced manufacturers and users to switch to new refrigerants, such as R410A, R407C, or newer, more eco-friendly HFO blends. For many users, this meant costly upgrades and equipment replacement. However, from an environmental protection standpoint, it was a necessary decision to limit the emission of ozone-depleting substances.
Although R22 is a banned substance today, installations that originally operated with it still exist. Many of them have been adapted to other refrigerants, but the issue of R22 recovery and disposal remains relevant. The history of this refrigerant is a cautionary tale – it shows that technical solutions that seem perfect can, over time, reveal their dark sides.
It is worth remembering that the substances that replaced R22 – for example, R407c or R410a – also turned out to be not entirely eco-friendly over time. Although they have a low or zero impact on ozone depletion, it later emerged that they have a high GWP index (Global Warming Potential) – meaning they contribute to the greenhouse effect – and they too will eventually be phased out. This time, they are meant to be replaced by R290 or R32. For how long?
R22 went from being an undisputed leader in the refrigeration industry to a symbol of substances harmful to the environment. Its peak coincided with a period of dynamic development in air conditioning and refrigeration, and its downfall was the result of global concern for the future of the planet. It's a story that proves technological innovation must go hand in hand with ecological responsibility.
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