GM Sticks with New Refrigerant, VW Balks

General Motors Co. says it will go ahead with plans to switch to a more environmentally friendly air-conditioning refrigerant in spite of warnings by Daimler AG that the fluid could catch fire in a crash and release toxic fumes.

But Volkswagen AG says it has suspended its conversion to the material HFO-1234yf pending further tests.

Daimler says it will continue using the current industry standard material, R134a, until it is convinced the new refrigerant is safe. GM says its own tests have been unable to replicate the issue Daimler claims.

HFO-1234yf was co-developed by DuPont and Honeywell. They insist the material is safe under "the most extreme conditions," pointing to three years of successful tests by SAE international and 18 independent laboratories.

The European Union has all but dictated the use of HFO-1234yf by mandating that manufacturers must begin shifting to ultra-low global warming potential (GWP) refrigerants this month. The EU rule would eliminate R134a by 2017.

HFO-1234yf has a GWP rating of 4 compared to 1,430 for R134a. The EU standard sets a GWP cap of 150 on replacement refrigerants. The new refrigerant has been approved for use in the U.S., but there is no federal requirement to use it.