A review of a refrigerant intended for use in automobile air conditioners has so far failed to raise any new safety concerns. SAE International, an automotive engineering group, organized the review two months ago after automaker Daimler said new tests it conducted showed that the refrigerant, hydrofluoroolefin (HFO)-1234yf, could leak and cause a fire in a head-on collision (C&EN, Dec. 10, page 34). An SAE study group concluded in 2009 that HFO-1234yf could be safely used in cars. The refrigerant was specifically developed by Honeywell International and DuPont to replace a refrigerant with high global warming potential. “With the exception of Daimler, no [automaker] in the cooperative research project has provided information that would suggest a concern for the safe use of HFO-1234yf,” SAE says. More than a dozen automakers are involved in the review, which is scheduled for completion by June 2013.