Fluoride Action Network

HFO-1234yf: New Refrigerant Takes Heat

Source: Chemical & Engineering News | November 17th, 2008 | By Marc S. Reisch
Location: European Union
Industry type: Greenhouse/Ozone Gases

TO RALLY public opinion against fluorine-based refrigerants, a German environmental group has recorded a car crash and staged a series of tests purporting to prove that a newly developed automotive refrigerant is both flammable and lethal.

Much to the consternation of the refrigerant’s makers – Honeywell Speciality Materials, DuPont, and Arkema – the crash and tests became the subject of a German television news program late last month. A group of environmental organizations, the Alliance for CO2 Solutions, has also posted the tests on the popular video-sharing website YouTube.

The fluorochemical makers say they have been vilified. They describe the new refrigerant, a hydrofluoroolefin known as HFO-1234yf, as the answer to the European Union’s 2011 ban on hydrofluorocarbon (HFC)-134a because of its contribution to global warming. And although the chemical makers agree that HFO-1234yf is flammable, they say it is no more hazardous than nonflammable HFC-134a, which is used in all car air conditioners today and has a history of safe use.

Honeywell, DuPont, and Arkema have all raised questions about the validity of tests conducted by the German Environmental Aid Association, whose German initials are DUH. “Frankly, we’re puzzled at their results,” says Ian Shankland, director of technology for Honeywell. He says Honeywell has asked to review details of the DUH tests.

DUH, which promotes carbon dioxide as a better refrigerant, says it has received Honeywell’s request for information along with legal threats if it doesn’t hand over testing details. A Honeywell spokesman acknowledges that his firm has made “a formal legal request to get their test methodology.”

Àlvaro de Õna, a spokesman for the Alliance for CO2 Solutions, whose members include DUH and the environmental group Greenpeace, says he is not surprised that chemical companies would question the test results. HFO-1234yf, he asserts, is the first in a new group of fluorochemicals with low or no global-warming potential (GWP) that Honeywell and other firms hope to introduce in the next few years. The CO2 alliance, he admits, is using the DUH tests as a way to turn public sentiment in favor of “natural” CO2 and halt the use of fluorochemicals in everything from refrigerators to supermarket freezers to room air conditioners.

FOR THEIR PART, chemical makers don’t dispute that they are defending the market for fluorochemical refrigerants. According to Ray K. Will, a senior consultant at SRI Consulting, HFC-134a used in home, auto, and retail refrigeration applications made up 16% of 2007 global fluorocarbon consumption of 1.2 million metric tons.

The trouble with HFC-134a is that it has a GWP 1,400 times greater than that of CO2, the standard against which other global-warming substances are measured. To meet its obligations to reduce global-warming gases under the Kyoto protocol, the EU ordered new carmakers to use refrigerants with a GWP of less than 150 starting in 2011.

With a GWP of 4, HFO-1234yf meets the EU’s standard. And although no other government entity yet requires a low-GWP refrigerant in cars, automakers that sell in many countries will want to reduce engineering, supply, and maintenance costs by using one air-conditioning system globally. Cooling systems that use HFO-1234yf, fluorochemical makers say, are more energy efficient than those that use CO2 and can be easily dropped into existing air-conditioning systems with a little tweaking.

CO2, by contrast, will require an entirely new compressor system that works at higher pressures than fluorochemical systems. Most people think of CO2 as a gas that pours out of power plant smoke stacks. However, the Alliance for CO2 Solutions hails CO2 as a white knight poised to both keep car interiors cool and help save the environment.

As Will, the consultant, sees it, CO2 refrigerants are politically more palatable to Western Europeans and, particularly, to the German public. Indeed, he points out that the German Automobile Manufacturers Association has endorsed CO2 as a refrigerant in new cars.

Troubling questions still have to be answered, Will observes. Because CO2 air-conditioning systems operate under high pressure, some experts are concerned that CO2 canisters attached to the system could become lethal projectiles in case of a car crash. If HFO-1234yf is flammable and HFC-134a is not, that is also cause for concern. Ultimately, “we might reach a fork in the road,” Will says, with German carmakers adopting CO2 while the rest of the world goes with HFO-1234yf.

Honeywell’s Shankland admits that HFO-1234yf is flammable, but he notes that it takes a very powerful spark or a fire to ignite it. In car crash tests that Honeywell and its independent labs conducted, HFO-1234yf did not cause or contribute to a fire, he says.

And whether CO2 or HFO-1234yf is more dangerous in a car crash is moot, Shankland asserts. Any fire would produce lots of toxic combustion products from the fuel, lubricants, hoses, and plastics under the hood. The breakdown products of HFC-134a, used for the past 14 years, and HFO-1234yf are the same, he says.

According to DuPont, flammability tests conducted in its own labs as well as those by carmakers and independent labs “indicate that HFO-1234yf is safe.” Arkema Business Manager Christophe Maldeme says the DUH video “cannot be taken as technical proof” that HFO-1234yf is hazardous. Automakers say they haven’t made a final decision, though time is running out to choose between the two refrigerant systems. General Motors says it expects to make a decision in about a month.

Fluorochemical makers say they have no plans to post a video on YouTube to prove the safety of HFO-1234yf. “That would not be the best way to commercialize a new product,” Shankland says. But while chemical companies expect most carmakers will choose HFO-1234yf on its merits, they’ll still have public sentiment in Europe, and especially in Germany, to contend with.