The announcement is the latest twist in a story that has attracted widespread public attention in Germany and beyond, following Daimler’s findings in September 2012 that the chemical refrigerant R1234yf is unsafe for use in its cars. Discussions since Daimler’s announcement have centred around questions regarding the flammability and toxicity of 1234yf, its potential harm to passengers and rescue personnel, and its potential impact on ecosystems and the atmosphere. German Federal Environmental Agency UBA, as well as leading researchers from Germany and Switzerland, and automotive clubs like ADAC, have all disputed the viability of 1234yf and/or openly backed CO2 refrigerant as the only long term viable and safe alternative in MAC systems.
Daimler’s announcement, made public during the Geneva Motor Show on Wednesday, is the 3rd confirmation concerning the development of CO2 MAC systems made in the last 6 years. The first VDA statement in favour of R744 was released in September 2007, reconfirmed in October 2008. In 2009, German carmakers turned away from CO2 to choose a chemical refrigerant that had only been tested to a lesser extent. Then, in September 2012, it was confirmed by real-life tests performed by Daimler that the synthetic substance 1234yf is flammable under various accident scenarios and component configurations in different car models. While other carmakers back 1234yf, Daimler announced that it would not use the flammable gas due to the release of toxic HF, considered a serious risk for the health of passengers and any persons near a burning car. Instead, CO2 has resurfaced as a safe refrigerant, although it remains a technologically challenging solution that requires further development time.