The automotive market is more than familiar with regulatory changes impacting its business. Whether this is fleet CO2 targets, safety ratings, battery regulations, or a host of other factors that have evolved over time. Automotive refrigerants have been targeted previously, but PFAS (per- and polyfluoroalkyl substances) are becoming a greater concern and look to be the next target for regulatory change. There are different approaches to replacing the incumbent R1234yf with PFAS-free alternatives, but each has its own trade-offs. This article will cover the most promising alternatives and IDTechEx’s report “Thermal Management for Electric Vehicles 2026-2036: Materials, Markets, and Technologies” predicts that there will be over 14 million kg of next-generation refrigerants required for EVs by 2036.
The Story So Far
Refrigerants are crucial for managing the temperature of the vehicle cabin in combustion engine vehicles as well as EVs. However, the efficiency of the thermal system and refrigerants is even more critical in an EV, as there is no waste heat from the combustion engine to use to warm the cabin in cold conditions. Some EVs, like the early BMW i3 and BYD’s more recent vehicles, also utilise refrigerant to cool the battery.
R134a was the standard (replacing chlorofluorocarbons, CFCs), but in Europe, due to its high global warming potential (GWP), it was banned for vehicles on a new chassis manufactured after 2010 and in all new cars from 2017. Other regions like the US have followed suit, although R134a still finds significant use in places like China. However, China has set out plans to prohibit the use of refrigerants with a GWP over 150 (similar to how other regions have previously), starting with vehicles seeking type approval from July 2029.
Since the prohibition of refrigerants with a GWP over 150, R1234yf has become the default option in Europe and the US, with a GWP of less than 4 in comparison to R134a at over 1400.
Impending PFAS Regulations
The definition of PFAS is rather broad, and the definition from the Organization of Economic Cooperation and Development encompasses nearly 5,000 unique chemicals. The concern with these substances is their persistence in humans, wildlife, and the environment. There is increasing evidence of potentially harmful effects, such as increased risk of cancer, developmental delays, and hormonal issues (per the US EPA and the OECD).
The European Union is considering a universal PFAS ban, as are several US states. If the EU decides to adopt the universal restriction, then the implementation timescale could vary widely, depending on whether automotive refrigerants receive a deferral. TFAs (trifluoroacetic acids) are also gaining attention as a problematic pollutant and R1234yf is actually more problematic than R134a in this regard, as emissions of R1234yf completely convert to TFA in the atmosphere, whereas only 21% of R134a does. With these concerns, it looks increasingly likely that Europe will take action against R1234yf.
Natural Refrigerants
Natural refrigerants serve as potential alternatives to R134a and R1234yf in automotive applications, with the two front-runners being R744 (CO2) and R290 (propane).
R744 (CO2) was first adopted by Mercedes in the S-Class in 2017, although it has since dropped this approach. The VW Group’s EVs on the MEB platform (e.g. ID3, ID4, Enyaq, etc.) use R744 in models that have a heat pump. R744, by definition, has a GWP of 1. It also has high efficiency in colder conditions and is relatively inexpensive, non-toxic, and non-flammable. However, R744 requires higher pressures to operate, making system design and safety more challenging. The R744 system has more complexity on the refrigerant side but less on the water coolant side. The other downside is poorer efficiency in hotter climates. Despite challenges, R744 is an alternative to R1234yf that has been deployed commercially, with nearly 1 million vehicles on the road, and in early 2024, VW announced it plans to convert all of its BEVs (battery electric vehicles) to R744 by 2030.
R290 (propane) is another potential alternative, with a GWP lower than 3 and no ozone depletion potential. It has better refrigeration capacity at high loads compared to R744 and is also relatively inexpensive. It can operate at a lower pressure too, somewhat simplifying system design. Compared to R744, R290 presents less complexity on the refrigerant side, but more on the coolant side. Other trade-offs include performance when heating in cold conditions, and the major roadblock is related to safety. Propane is highly flammable, and certain regions restrict the use of flammable refrigerants. Suppliers like Hanon Systems have presented R290 air conditioning systems, and ZF demonstrated a concept EV with R290 in 2023, with plans for deployment in 2026. In 2025, Ford (in the US) submitted an application for R290 to be approved for use as an automotive refrigerant.
At this early stage, R744 looks to be the preferred natural refrigerant for the European market and R290 for the US market. China may not have PFAS-related regulations, but it has also seen domestic suppliers taking a great interest in R744 and R290, either to supply international markets or to bypass the next stage of regulatory changes in China.
New Refrigerant Blends
Natural refrigerants are promising but require a complete redesign of the vehicle’s refrigerant system, and engineered materials may not be done quite yet. Several chemical companies are looking at developing alternative refrigerant blends. For example, Daikin has developed R474A and R491A, and SK Enmove has developed R494B and R4101A. SK Enmove’s R494B is a direct PFAS-free drop-in replacement for R1234yf (with a change to refrigerant compressor oil) and has somewhat improved thermal performance.
Each of these new blends will have to be evaluated, they all fall below the 150 GWP target, and some of them are PFAS free, but they vary in GWP, and more long-term reliability testing needs to be done in real-world driving conditions. Nevertheless, these present an interesting alternative to R1234yf that wouldn’t require such a drastic overhaul to vehicle architecture, and could prove an excellent solution for vehicles on existing platforms that are being carried forward.
Outlook
Whilst the regulations are yet to be defined around R1234yf, we could certainly expect to see bans implemented in the future. IDTechEx believes that R744 and R290 are the two most immediately viable alternatives and that R744 will be favored, at least initially, due to it being in the later stages of commercialization and having fewer safety concerns. However, there may be innovation required to improve its higher temperature performance to meet the needs of hot climates and thermally demanding fast charge scenarios. IDTechEx also expects adoption of alternative refrigerant blends, especially for vehicles that want to carry forward existing thermal architectures.
