The automotive market is well-acquainted with regulatory changes that impact its business. Whether this is fleet CO2 targets, safety ratings, battery regulations, or a host of other factors that have evolved. Automotive refrigerants have been previously targeted, but PFAS (per- and polyfluoroalkyl substances) are becoming a greater concern and appear 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 trade-offs. This article will cover the most promising options.
According to IDTechEx’s report, “Thermal Management for Electric Vehicles 2026-2036: Materials, Markets, and Technologies,” over 14 million kilograms of next-generation refrigerants will be required for EVs by 2036.
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 utilise for cabin warming 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, or CFCs), but in Europe, due to its high global warming potential (GWP), it was banned for vehicles with new chassis manufactured after 2010 and in all new cars from 2017.
Other regions, such as 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, which has a GWP of over 1400.
Impending PFAS Regulations
The definition of PFAS is rather broad, and the definition from the Organisation for 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 ban on PFAS, 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 more complicated than R134a in this regard, as emissions of R1234yf completely convert to TFA in the atmosphere, whereas only 21% of R134a do. 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 R744 (CO2) and R290 (propane) being the two front-runners.
R744 (CO2) was first adopted by Mercedes in the S-Class in 2017; however, it has since discontinued this approach. The VW Group’s EVs on the MEB platform (e.g., ID3, ID4, Enyaq, etc.) utilise R744 in models equipped with 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. In early 2024, VW announced plans to convert all of its battery electric vehicles (BEVs) to R744 by 2030.
R290 (propane) is another potential alternative, with a GWP lower than three and no ozone depletion potential. It has better refrigeration capacity at high loads compared to R744 and is also relatively inexpensive.
It can also operate at a lower pressure, which somewhat simplifies 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 primary 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 appears to be the preferred natural refrigerant for the European market, while R290 is expected to be the preferred choice 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 they require a complete redesign of the vehicle’s refrigerant system, and engineered materials may not be fully developed yet. Several chemical companies are exploring the development of alternative refrigerant blends.
For example, Daikin has developed R-474A and R-491A, while SK Enmove has developed R-494B and R-410A. 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 need to be evaluated, as they all fall below the 150 GWP target. Although some are PFAS-free, they vary in GWP, and further long-term reliability testing is required in real-world driving conditions.
Nevertheless, these present an enjoyable alternative to R1234yf that wouldn’t need 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 surrounding R1234yf have yet to be defined, we can 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 favoured, at least initially, due to its later stage of commercialisation and fewer safety concerns.
However, innovation may be required to enhance its performance at higher temperatures, meeting the needs of hot climates and thermally demanding fast-charging scenarios.
IDTechEx also expects the adoption of alternative refrigerant blends, especially for vehicles that aim to retain their existing thermal architectures.