PFAS are a large family of synthetic chemicals characterized by extremely strong carbon–fluorine bonds. This makes them very persistent – hence the term “forever chemicals.” But they are also harmful to health and can accumulate in humans and animals upon exposure, with studies linking them to severe consequences such as cancer and reproductive issues. As a result, regulatory actions have been initiated worldwide, particularly in the EU. Under current chemical legislation, a comprehensive PFAS restriction is being prepared.
Great properties with dangerous side effects: PFAS have very low surface energy. This makes them repellent to water, dirt, and grease, which is why they are used in so many products: outdoor clothing, coffee cups, cosmetics, non‑stick cookware, and raincoats, but also in elastomers and sealing materials for screws. And: PFAS are also present in the refrigerants used in modern automotive air‑conditioning systems.
For many decades, R134a was the standard refrigerant in automotive A/C systems. It has relatively low toxicity and good thermodynamic properties. However, it has a high global warming potential (GWP) and is a fluorinated compound.
In response to stricter climate regulations in the EU, R1234yf has replaced the “old” refrigerant R134a in most vehicles. Compared with R134a, it has a very low global warming potential. Despite its climate benefits, R1234yf is a fluorinated organic substance and – depending on the legal definition used – is classified as part of the broader PFAS family. Moreover, degradation products such as trifluoroacetic acid (TFA) are difficult to break down in the environment.
In early 2023, the EU member states Germany, Denmark, the Netherlands, Norway, and Sweden submitted a proposal to the European Chemicals Agency (ECHA) to restrict all PFAS across all applications and uses. At the end of August 2025, ECHA announced that it had evaluated around 5,600 scientific and technical submissions. The process of determining which substances will be banned, for which applications, and with what transition periods is still ongoing.
Currently, a transition period of 13.5 years is proposed for the existing fleet of vehicles with combustion engines as well as medium to heavy-duty BEVs, and 6.5 years for electric vehicles (passenger cars). However, the restrictions are expected to take effect no earlier than the first quarter of 2028. A new legislative proposal on the ban is anticipated later this year, accompanied by a consultation process with a resulting summary provided by the ECHA to the EU-commission.
Carbon dioxide (CO₂) as a refrigerant is not new, but it has not yet become widely established. As a natural refrigerant, it has a very low GWP (1 – it is the reference). It offers strong heat pump performance and is particularly attractive for electric vehicles that use integrated thermal management for the cabin, battery, and power electronics. The downside is the very high operating pressure, which places significant stress on all system components (compressor, piping, etc.). Nevertheless, CO₂ air‑conditioning and heat‑pump systems are already on the market in some vehicles, such as the VW ID family.
Another natural refrigerant with a very low GWP (0,02) is propane (R290). It is extremely energy‑efficient, and its lower operating pressure can potentially reduce the cost of A/C components and system design. However, propane is flammable. This requires strict safety measures in vehicle design, such as limiting the refrigerant charge, implementing leak detection systems, careful routing of refrigerant lines, and robust ventilation concepts.
These additional safety requirements can increase system complexity and typically require a complete redesign of the air‑conditioning system with components placed outside the passenger cabin and a fully indirect system. It also means no direct evaporation in evaporator in the cabin and no condensation in the cooling module. Global approval programs for the refrigerant are still underway.
MAHLE is a development partner for vehicle manufacturers in the fields of air‑conditioning and heat‑pump systems. Its expertise in system engineering, compressors, heat exchangers, valves, and controls drives the development of thermal‑management systems using environmentally friendly refrigerants. This knowledge directly benefits the service industry as well. MAHLE is currently developing a special A/C service unit to enable safe and efficient maintenance and repair of CO₂ systems in workshops.
Workshop tip: keep it cool!
The business of refrigerant replacement will remain profitable for a long time and continues to be a valuable service for drivers. Service‑equipment experts like MAHLE and relevant industry associations will communicate early about regulatory changes from Brussels and ensure that workshops stay up to date with information and equipment.