UPDATED: Daimler announces HFC1234yf to be unsafe for its vehicles

"Daimler has provided relevant authorities with the findings of an investigation which raises questions on the safe usage of the new internationally recognised R1234yf refrigerant. (…) Due to the new findings of this study and the high safety demands at Mercedes-Benz, this chemical will not be used in its products,” reads the official Daimler statement of 25 September 2012. "The company therefore wishes to continue to use the proven and safe R134a refrigerant in its vehicles”.

Several German media sources have reported the news with Auto Bild’s headline stating: “R123yf on the brink of collapse”, and continuing with, “Daimler pulls the plug. (…) Sensational U-turn in the killer refrigerant case: Mercedes will not use R1234yf in the future. Tests with several new models showed: the new refrigerant is highly flammable! Auto Bild had requested such tests for a long time. Now Daimler has proven that R1234yf can generate a fire if it gets - under real-life conditions - on hot motor parts such as the turbo charger or exhaust manifold. In that case highly toxic HF is formed."

A Daimler spokesperson confirms: “We cannot do this to our customers.”

Drivers that bought one of the few Daimler SL series sports vehicles already equipped with the new refrigerant would now be entitled to retrofit their car back to the old refrigerant.

Is it safe or is it not?

With this company statement, the German carmaker seems to be breaking away from the official line of the German Association of the Automotive Industry (VDA) that has been testifying on the safety of the chemical substance: In 2010, when the German Association of the Automotive Industry (VDA) made a u-turn from their 2007 and 2008 public commitments to CO₂, switching to HFC1234yf in car A/C instead, they were communicating that in the past two and a half years 1234yf had been under close scrutiny and that “the unequivocal result of these extensive investigations is that HFO-1234yf is as safe to use as today’s refrigerant and can therefore be used in vehicle air-conditioning systems without cause for concern”.

Back then carmakers chose to lay to rest safety concerns regarding the flammability and toxicity of 1234yf voiced by other associations, concerns that were confirmed in tests by the Federal Institute for Materials Research and Testing (BAM).

Daimler now refers to “multiple confirmations of non-critical results” from laboratory and crash tests done by other carmakers. It developed an own in-house test under “real-life” conditions to go beyond the legal requirements for such tests. The result: “In the new real-life test scenario, the refrigerant is dynamically dispersed at high pressure near to hot components of the test vehicle's exhaust system. This corresponds to a serious head-on collision in which the refrigerant line is severed and the reproducible results demonstrate that refrigerant which is otherwise difficult to ignite under laboratory conditions can indeed prove to be flammable in a hot engine compartment”.

The carmaker also highlights that the results could be reproduced at any time, and has made the results publicly available for other carmakers and associations to verify them.

Other VDA members considering test results

It is possible that more VDA members follow suit with similar announcements, with Daimler’s Research, Development and Environmental Communications Head of Media Relations Matthias Brock telling R744.com: “We have informed our VDA partners about our findings and they are looking into that”.

The announcement might not come as surprise, as Daimler was among the companies that filed formal objections to Honeywell’s HFC1234yf patent with the European Patent Office (EPO), that lead EPO to issue in April 2012 a decision revoking Honeywell’s European patent regarding a family of chemicals that includes 1234yf. Besides Daimler, objections were filed with EPO by BMW AG, the European Automobile Manufacturers Association ACEA that represents the interests of the 18 European vehicle manufacturers (including Daimler, WOLKSWAGEN and BMW), as well as fillings by Arkema France, Daikin Industries, Asahi Glass Co., Mexichem, Solvay Fluor and European patent attorney Michael Wallinger.

German newspaper Die Welt reported on 26 September 2012 that VOLKSWAGEN has said that “We will analyse the findings carefully. Only after that we can draw further conclusions”.

In search of a long-term alternative

“Until further notice, the tried-and-tested R134a refrigerant is the technical alternative. In such a globalised world, there can really only be a single refrigerant which all vehicle manufacturers use”, Matthias Brock, Daimler’s Research, Development and Environmental Communications Head of Media Relations, told R744.com. “We will involve ourselves extensively in the international selection process. Together with our technology partners, we will be intensively looking at a long-term solution”.

"This (R134a) is a temporary solution, we are looking for alternative refrigerants", he told Auto Motor Sport.

Delaying MAC Directive enforcement indefinitely?

In mid 2012, the European Commission issued an official note allowing carmakers to continue using high Global Warming Potential (GWP) refrigerant R134a in the air-conditioners of new types of vehicles until the end of 2012. The decision followed DuPont and Honeywell communicating in late 2011 that unlike what was previously thought, they will not be able to supply the full amount of 1234yf refrigerant needed until the 4th quarter of 2012.



With this major announcement made today by the leading carmaker, several questions need to be asked:

• Who will follow suit?
• What does this mean for the implementation of the EU MAC Directive?
• What does this mean for other alternatives such as R744 or hydrocarbons?

R744.com will be reporting about developments over the next days.