Daimler made a public announcement on September 25, 2012 regarding in-house testing that they suggest reached significantly different safety conclusions from previous industry findings. DuPont has met with Daimler to understand their testing and we concluded that their testing does not represent new information. It is well known that HFO-1234yf is a mildly flammable refrigerant, and this factor has been thoroughly evaluated by independent laboratories.
Daimler testing did not involve true crash conditions.
Daimler did not perform actual crash tests and, in fact, there have not been any documented cases of actual vehicle crash tests by any party where HFO-1234yf ignited. To our knowledge, no OEM has been able to replicate the Daimler testing results to date, and we do not believe Daimler has incorporated their test results into a risk assessment.
The Daimler test involved a number of artificial and exaggerated scenarios rather than actual crash testing or real-life test conditions. For example, the test used a special valve close to the engine block that sprayed a vaporized mist of refrigerant plus oil directly onto a hot engine surface that had been heated significantly above normal car engine surface temperatures. Normal crash conditions would likely generate a sudden, random dispersal of the refrigerant under the hood, rather than an aimed spray. Also, in a sudden release, the refrigerant would be released from multiple locations and quickly diluted with air.
Further, Daimler testing appears not to have followed industry recommendations for safe use of HFO-1234yf (ISO 13043 and SAE J639), such as re-routing refrigerant lines away from hot surfaces and shielding hot surfaces. Unfortunately, unlike prior related industry testing, Daimler’s recent test results were not publicly presented to industry peers and stakeholders that have studied HFO-1234yf for the past four years to allow a full balanced review. DuPont has offered to provide technical expertise to work with Daimler and other OEMs to resolve questions about the adoption of HFO-1234yf as a more sustainable automotive refrigerant, in time to meet the requirements of the MAC Directive by January 1, 2013.