By on December 30, 2013


Remember R1234yf – the replacement refrigerant for R134a that can be potentially fatal, rather than just harmful to the environment? After a protracted battle between Mercedes-Benz and the EU over the use of the new refrigerant, which is flammable and extremely toxic, the adoption of R1234yf appears to be in full swing.

A report in Automotive News claims that the adoption of R1234yf will leave auto makers eligible for CAFE credits. As many as 500,000 vehicles in US showrooms have adopted R1234yf, including the Honda Fit EV, Cadillac XTS and Jeep Cherokee. The switch was prompted by concerns over greenhouse gases, as R134a is some 1,430 times more potent at trapping heat in the atmosphere than carbon dioxide. 1234yf is also much more expensive, at roughly ten times the cost of R134a.

Despite the health and safety concerns regarding R1234yf, the relentless drive to switch over to it seems to be driven by a policy of putting the environment before people, no matter what the consequences may be. While the EU has resorted to legal action against non-compliant auto makers, the EPA has offered credits to auto makers that switch over to the new substance to help them meet CAFE requirements, adding yet another layer of complexity to a framework riddled with loopholes and unfortunate incentives.

Automakers like Mercedes-Benz are eager to switch over to CO2 as the new standard for refrigerants, but that would require higher-pressure HVAC systems in car, which would in turn have a negative impact on fuel economy.

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23 Comments on “Credits For Dangerous Refrigerant Is The Latest In CAFE Loophole...”

  • avatar

    I like air conditioning too much to actually care how it cools me off. Although I do suppose I would be willing to pay more for less harmful refrigerants. Seems to me though that it is a matter of picking your poison. The newer refrigerant, while highly toxic, appears to be better for the atmosphere. While the vast majority of drivers will never touch, see or otherwise come in contact with the refrigerant in their vehicles, so it would seem the new type is probably a good alternative. However, you can speculate that down the line, people in the auto repair business, the shadetree mechanics and the patch of ground that the car is finally laid to rest on in some junkyard may not be so happy about the change over.

    I can see the lawsuits now over groundwater contamination or BillyBob accidently killing himself trying to swap out AC in his beater.

    • 0 avatar

      @thegamper – it could be a major problem in a MVC. The A/C system could rupture releasing the chemical. There is a potential that the refrigerant could be discharged into the passenger compartment. Not to good for an occupant trapped in the vehicle.
      It could delay extrication and occupant care if rescue workers have to don Scott Air Packs or respirators that will protect them from the chemical.
      If the EMS system decides to treat all MVC’s as toxic spill environments that will put car crash victims at greater risk.

  • avatar


    as I understand it the SAE has tested 1234yf and found the refrigerant itself to not be flammable. What Daimler probably had happen was the (combustible) mineral oil compressor lubricant caught fire after hitting something hot, and the flame from the burning oil caused the refrigerant to break down into nasty stuff.

    The kicker is that the current refrigerant (HFC-134a) breaks down into the same nasty stuff when exposed to flame; but it requires a glycol-based compressor lubricant which isn’t anywhere near as combustible as oil.

    • 0 avatar

      I may just be repeating mis-information, but…

      I had understood that HF-1234yf was slightly flammable, and that it used the same non-mineral-oil lubricants as R-134a. The Mercedes discovery was that a pinhole leak spraying HF-1234yf onto a cherry-hot exhaust manifold (test car had a turbo) caused the HF-1234yf to decompose into some sort of nasty fluorine-based chemical. The resulting chemical fog etched the test car windshield glass! (The chemical is also supposedly really, really, really bad for people.)

      The hypocrisy here is that many other worthy refrigerants have been dinged for flammability; the old story was “R-12 and R-134a are completely fireproof, therefore (!!) no automotive refrigerant may be flammable AT ALL.” And now the newly-anointed refrigerant is also somewhat flammable, or at least, potentially dangerous.

      (BTW, R-134a is also pretty bad for people, if you breathe it in an enclosed space. Obviously this doesn’t seem to be an issue in the real world.)

      Annnd, recalling R-12, it was indeed fireproof, but the mineral oil used with it wasn’t, and a fog of R-12 and mineral oil would burn readily. (AFAIK, the R-134a lubricants aren’t flammable.)

      Many countries (including Australia, I believe) permit HC (hydrocarbon) refrigerants in cars. The old 80/20 mix of propane and butane apparently works well, mixes with mineral oil, isn’t poisonous, works in all existing systems (if you flush out the R-134a lubricant), and it’s really, really cheap.

      The US EPA would like to ban HC refrigerants until somebody, anybody, will pay for testing to show that they’re “safe.” And nobody will pony up that testing money because you can’t patent propane+butane.

      As for the flammability of HC refrigerants: If I’m in a car wreck, I’m more concerned about the 100+ pounds of gasoline in my tank than I am about 2 pounds of propane in my A/C.

      I gather that carbon dioxide can be used for refrigeration, but it requires much higher pressures than R-12/R-134a/HF-1234yf. I don’t think it follows that CO2 will be less efficient; just that the entire A/C system will need to be re-imagined with different, much heavier materials.

      HF-1234yf is just the latest attempt by the refrigerant industry to patent a critical, necessary chemical so they can plunder the rest of us. And it looks like they’re winning.


      • 0 avatar

        thanks. I had thought 1234yf used mineral oil, but I’ll look into it further. But yes, you’re correct; HFO-1234yf gets nasty by decomposing into hydrogen fluoride when exposed to high temps, which turns into hydrofluoric acid after getting in the body. HF is nasty, nasty stuff. Problem is, R-134a also has HF as a decomposition product when exposed to high heat. I’m trying to figure out what “slightly flammable” means in this context.

        Of course, under these conditions R-12 would decompose into phosgene which ain’t very pleasant in its own right…

        “I don’t think it follows that CO2 will be less efficient; just that the entire A/C system will need to be re-imagined with different, much heavier materials.”

        true; seems like ever since R-12 was banned the focus has been on finding a refrigerant which wouldn’t cause too much disruption. R-134a doesn’t work *great* in a system designed for R-12, but it does *work* so long as you do a couple of relatively minor things. HFO-1234yf supposedly works in R-134a systems with no modification. CO2 would work well but as you say would require a re-thinking of the refrigeration circuit design.

        I hope this doesn’t lead to the industry needing to go to cascade systems.

        • 0 avatar

          The amount of phosgene that results as a byproduct of R-12 combustion is small as is the amount of hydrogen fluoride that results from as R-134a combustion. These gases also don’t support combustion on their own, and any flame goes out as soon as the heat source is removed. R-1234yf is naturally flammable and will keep burning. The oil did increase the combustion effects for sure, but it was way worse than R-134a. I’ve talked to some engineers that were working on a electric B-class. They said that the fear of this stuff is very justifiable. They brought the car to our store because we have a Cadillac sister store and were the only Mercedes dealer in the immediate area that could evacuate their R-1234yf system. Short of igniting it ourselves, this to me is the most believable source. The main point here is that Diamler has nothing to gain from fighting this stuff. They also said the efficiency of the CO2 system is coming along, and that they are working with compressor suppliers and are getting very close. With a correctly designed system, the efficiency will be there. Look at the R-410a home systems. They run crazy high pressures, but are now more efficient than any R-22 system ever was.

          • 0 avatar

            stationary installations have the advantage of not needing joints/couplings which can be disassembled. most fittings and unions are soldered together.

          • 0 avatar

            My point was just that they figured out how to run a compressor efficiently at the high pressures that R-410a needs to work, and will do the same for CO2.

    • 0 avatar
      George B

      JZ78817, this experiment by OBRIST Engineering comparing the flammability of R134a/PAG oil, R1234yf/PAG oil, and CO2/PAG oil looks pretty bad for R1234yf.

      One caveat is this paper is on a website dedicated to promoting R744, carbon dioxide, as the replacement refrigerant. However the experiment using actual VW A/C components shows that the combination of R-134a/PAG oil doesn’t readily ignite or sustain combustion when sprayed on a hot surface while the R1234yf/PAG oil combination ignites and burns big time. Thus, there is some decomposition of both refrigerants where they hit the hot surface, only the R1234yf also decomposes on a large scale in a fireball. Wouldn’t be surprised if the environmentally friendly breaks down easily in the atmosphere molecule also decomposes more easily with heat than the more stable longer lasting one.

  • avatar

    I have come to believe that all this refrigerant regulation is 2% environmentalism, 1% safety and 97% cronyism.

    Did anyone ever even go back to show that having banned all the supposedly nasty stuff we had before there has actually been a change for the better or is it just the usual “it would have been worse” nonsense?

    • 0 avatar
      George B

      Ward Atkinson of the Mobile Air Conditioning Society is a rent seeking weasel. Guaranteed that they will try to get a regulation that forces every quick lube shop that even adds refrigerant to buy a second R1234yf refrigerant recovery machine to go with the R134a machine that they don’t really need just to add refrigerant. Ward had a company makes those machines.

      I have a almost 15 year old car with all original air conditioning hardware that has never had anything but new refrigerant and PAG oil from cans added. PAG oil is extremely hygroscopic and moisture is really bad for car air conditioning. I’m convinced that never letting some numbskull with a poorly maintained refrigerant recovery machine connect to my car has extended the life of my car air conditioning system.

      • 0 avatar

        If you’re adding cans to your system, you have a leak. A/C systems never need to be recharged unless they’re leaking.

        • 0 avatar
          George B

          Automotive A/C systems typically leak about 1 to 2 oz a year. They have a mechanical shaft on the compressor that’s hard to seal. Leaks more as the car gets old. I need to add part of a 12 oz can every couple years. The leftovers go into my neighbor’s cars.

          • 0 avatar

            No, they don’t have to leak at that rate. I’ve never added any refrigerant to my Probe, which is about to celebrate its 19th birthday.

            …..the relentless drive to switch over to it seems to be driven by a policy of putting the environment before people….

            What a load of $hit that comment is. The environment has taken it on the chin for as long as there have been people. And people have been taking it for as long as other people can make money on them – and they made lots of it….

    • 0 avatar
      SCE to AUX


      The way I read this story, the worldwide ozone-saving efforts have been misguided:

  • avatar

    Just wondering if anyone has taken into account and found a fix for the possibility of a refrigerant line leaking/dumping after an accident.

    • 0 avatar

      I’d say the possibility is pretty darn high, given the condenser is right up there in front of the radiator. whether the leaking refrigerant can find a surface hot enough to decompose is another story. Pretty much any refrigerant containing fluorine can turn into HF when heated to a high enough temperature.

  • avatar

    It’s a pity that car a/c designs haven’t come up with the air cycle machine used in aircraft. No refrigerants’ just turbines, compressors mixer valves and heat exchangers. With the production of micro turbines and lightweight aluminium alloys, the only thing would be the initial costs. But it’s safe for the environment, no nasty gases, no green house gases. Think of the children!

    • 0 avatar
      Big Al from Oz

      Essentially an A/C unit for a car works on the same principles, except it takes less energy to compress and expand a refrigerant.

      An aircraft style ECS system would be bulky, have much more weight and be more complex.

      I know the first thing most would say, then why use in aviation?

      Well, a gas turbine is a massive air pump and relatively uncontaminated air can be bleed off roughly halfway through the compressor to provide the necessary air and energy to operate the system.

  • avatar

    As usual, follow the money…

  • avatar
    Big Al from Oz

    Here is a link from Honeywell for the R1234yf. It appears relatively easy and safe to use if you follow the precautions and wear the applicable PPE (Personal Protective Equipment).

    I don’t know if some here have ever worked with MSDS now SDS (Material Safety Data Sheets). I have to use these quite often to assess hazards and the associated risks for my guys at work.

    If anyone comes across a chemical they are unfamiliar with just google the name of the chemical followed by MSDS. This could reduce the risk of injury from lack of knowledge.

    In the case of this refrigerant I typed “R1234yf MSDS” into google.*&C101=*&C102=*&C005=000000011078&C008=&C006=HON&C013=+

  • avatar

    Who is to argue with that? If Honeywell says it’s safe than it most be so. They would have no reason to be less than truthful would they?

    • 0 avatar

      I believe MB. Honeywell makes this stuff so they will tell you anything to sell more of it. I can see why MB is running scared. If there is a fatality or injury arising from this, MB will be the one to get sued not Honeywell. Honeywell could wash their hands just say the product is safe and it’s simply a poor MB design that allowed a heat source to get in contact with the refrigerant. I doubt it’s a matter of cost because MB is one company that could easily pass on higher costs to their customers.

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