DUHGERMANY: With Germany on the brink of being dragged before the European courts over its failure to enforce the MAC directive, arguments over the safety of R1234yf have escalated.

Refrigerant manufacturer Honeywell has responded to new safety tests by the German environmental group DUH, accusing it of running a misleading campaign.

Tests carried out to measure the amount of toxic hydrogen fluoride (HF) produced in the event of a fire in a road tunnel are said by the DUH to have shown that R1234yf “is even more dangerous than previously thought.”

The test was carried out by a subsidiary of TÜV Nord, on behalf of the DUH, not to question the flammability of R1234yf as previous tests had done but to check the concentrations of HF in an enclosed space such as underground garages or road tunnels in the event of a fire. The test was carried out with a new, but unnamed, car currently using the new refrigerant. Potentially dangerous HF concentrations of nearly 45ppm were said to have been measured.

Commenting on the tests, a Honeywell spokesperson said “It is disappointing that DUH would invest its time in tired publicity stunts to restate very old claims that have been repeatedly invalidated by industry experts, regulatory authorities and automakers. Comprehensive safety tests have all concluded that HFO-1234yf is safe.”

Honeywell also accused the DUH of “attempting to limit consumer choice by forcing everyone to accept CO2 as an air-conditioning refrigerant, a solution that has been shown by two decades of investigation to be less safe, less cost-effective and less beneficial to the environment.”

Pointing out that there are already around 100,000 cars in Germany using R1234yf, the DUH’s Patrick Huth maintained that based on this latest information “It would be irresponsible for political leaders, but also the manufacturers, to continue to close our eyes to this danger.”

Daimler’s refusal to adopt the new refrigerant on safety grounds following its own flammability tests is expected to prompt the EU to issue infringement proceedings against Germany tomorrow (Thursday) for its failure to enforce the MAC Directive which demands that all new cars must use a refrigerant with a GWP of less than 150.

All HFCs, including the new HFOs, will produce HF when burned. This also includes R134a, which has been the universal car air conditioning refrigerant for many years. In theory, at least, R134a would produce more HF in similar tests due to the fact that it has a higher fluorine content.

Patrick Huth told the Cooling Post that R134a was not as reactive as R1234yf as proven in previous tests by both the DUH and the Federal Institute for Materials Research and Testing. “While the ignition temperature of R1234yf is around 405ºC, R134a does not ignite at hot surfaces at a temperature of 800º or even 900ºC. In our latest test, the temperatures of the burning car did not exceed 900º Celsius. Therefore, a similar test with R134a was not conducted.”

Germany to face euro court over MAC directive January 20, 2014

Firefighters call R1234yf “dangerous” – December 19, 2013