There are few inventions throughout history as ever-evolving and impactful as refrigerants. While the thought of refrigerants may rarely or never cross your mind, you are constantly in contact with them. You decide you want some ice cream for dessert tonight, you have the air conditioner on in your car, or you walk inside of the mall to stay cool on a summer day… all of these scenarios would not be possible without refrigerants.

A timeline of early refrigerants

In 1755 William Cullen designed a small refrigeration machine, kept cool by Ether; he did so by boiling the Ether which would, as a result, absorb heat from the surrounding area. Skipping ahead roughly a century, a man named James Harrison was responsible for creating the first vapor-compressed refrigeration system as well as an artificial ice-making machine, kept cold by Ammonia. By the 1920s, air conditioners had started to pop up around the country, however, these units were expensive, prone to breakdowns (which required more money to be dished out for repairs), and were deadly if a leak occurred, as they were using refrigerants like Ammonia and Sulfur Dioxide.

To combat these problems, companies set out to develop a refrigerant that was not volatile and had no toxicity levels to improve residential and commercial safety. After some time, a refrigerant that goes by R-12 Freon was conceived. R-12 was a revolutionary type of Dichlorodifluoromethane (CFC) refrigerant, and can often be referred to as the grandfather of refrigerants. Shortly after CFCs hit the market, a neighbor refrigerant was born called R-22, a Hydrochlorofluorocarbons (HCFC) refrigerant. CFCs changed the industry, making refrigerants common and accessible to the average person.

Environmental impacts of CFCs and HCFCs

By the 1950s, CFCs and HCFCs were dominating the refrigerant industry across the globe. But, because the environmental danger caused by these refrigerants was previously unknown, they had been weakening the ozone layer as they accumulated in the stratosphere over the decades. However, once the 1970s rolled around, concerns raised were by environmentally-conscious groups about the potential effects of ozone-depleting substances (ODS). After studying the effects the ODS were having, the international community impressively banded together to hold the Vienna Convention for the Protection of the Ozone Layer in 1985. A direct step resulting from the meeting was the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.

Under the Montreal Protocol, ODS are regulated as either Class I (CFCs), or Class II (HCFCs) substances. The Class I substances were set to be phased out by the end of the ‘90s. The phaseout of Class II substances was given a longer stretch of time, and will conclude with no production or importing of HCFCs of any kind in 2030. The deadline for the Class II phaseout is substantially longer because the common HCFC mentioned earlier, a.k.a. R-22, and HCFC-142b are in so many commercial and residential systems that they will take a longer amount of time to adjust.

The third generation of refrigerants

Post-Protocol, the third generation of refrigerants was created in the 1990s to eliminate the need for the previous refrigerants; Hydrofluroolefin refrigerants (HFCs) were thought to be safer for the environment because HFCs did not contain Chlorine like the CFCs and HCFCs did. In theory, the HFCs should have solved the environmental issue, right? Wrong.

As time passed, scientists and environmental researchers found out that HFCs had a staggeringly high Global Warming Potential level, referred to as GWP. Now, the popular greenhouse gas that most people associate with global warming is carbon dioxide; if we scale GWP of carbon dioxide at 1, the Global Warming Potential of a common HFC refrigerant called R-134a is between 1,300-1,400. This means that while the HFCs are not directly attacking the ozone layer like CFCs and HCFCs, the HFCs are trapping in enormous amounts of greenhouse gases, contributing to global warming.

So, this led to an international push to rid the industry of all HFC refrigerants. But, because HFCs did not contain Chlorine, as previously stated, the HFC ban could not take place under the umbrella of the current Montreal Protocol. As a result, the Kigali Amendment to the Protocol was signed in 2016, which allowed a phaseout and eventual ban of HFCs.

The new and now

Hydrofluroolefin (HFO) refrigerants are the newest type of refrigerant to hit the market. HFOs are considered to be the refrigerants of the foreseeable future and are aimed at providing a safe, non-ODS, and low-level Global Warming Potential. But, no refrigerant is perfect. While the GWP is exceedingly low, coming in at a mere 4, the offset is that HFOs are slightly higher-risk when it comes to flammability.