Radically differing views of the German road safety authority's (KBA) final refrigerant report have emerged as the long-running coolant saga shows no sign of ending.

The KBA's report was not initially available in English, but both chemical manufacturer, Honeywell and German automaker, Mercedes-Benz, confirmed its publication.

Mercedes has long maintained the 1234yf coolant could present a fire hazard in certain conditions, while Honeywell insists it poses no greater threat than the 134a coolant variant currently in use.

"Our reaction is the final results are the same as the KBA stated in its preliminary report - it does not change our position at all," a Mercedes spokesman told just-auto from Germany.

"For us, the important conclusion is a vehicle using 1234yf has worse safety level[s] than vehicles using 134a. Using 1234yf would be a step back in terms of safety.

"That does not match our safety requirements at Mercedes, so that is why we stick to our position not to use this refrigerant."

Mercedes says it is developing a CO2-based coolant for air conditioning systems for use in 2017, but until then maintains it has valid type approval for all its vehicles.

Honeywell however, counters with its view the KBA report confirms 1234yf can be used safely in cars and that "with the exception of Daimler," there is broad consensus it poses no greater risk than 134a.

"Proven time and again to be a safe and cost-effective automobile refrigerant, HFO-1234yf is available now with a global warming potential of less than 1, which is 99.9% better than HFC-134a," said a Honeywell statement emailed to just-auto.
 
"Sadly the EU Mobile Air Conditioning (MAC) Directive - a landmark piece of legislation designed to reduce greenhouse gas emissions and help the environment - took effect this past 1 January and has yet to be fully enforced.

"The overdue final report from KBA adds no new information to its preliminary report from this past August and is a reminder of how compliance with the MAC Directive has been delayed far too long by the actions of a single automaker that has decided not to comply with the rule of law."

The row has engulfed a wide variety of actors including France's top Court, the Council of State, that repealed the country's earlier ban on Mercedes models using 134a, as well as the European Commission (EC) and the German Transport Ministry.

Mercedes was unable to sell its A, B, CLA and SL vehicles using the 134a refrigerant as the blockade took effect, with France's dealer association warning it might have to make up to 1,500 staff partially redundant as a result.

The EC has referred the impasse to its Joint Research Centre, which has been conducting its own analysis of the situation that rapidly escalated up the political ladder earlier this summer.

"I think the EC is waiting for the conclusion of the JRC," said the Mercedes spokesman. "They are also in close discussion with the German Ministry of Transport and we are not directly involved in that."

The KBA was not immediately available for comment.