I'm curious about which and how much of a refrigerant is commonly used in modern refrigerators (say, produced from 2000 onwards). How harmful is it for the environment? What is the ozone depletion potential.

I found this little paragraph on Wikipedia but it does not say how much less harmful R-134a is compared to R-12 - it doesn't mention quantities either:

Commercial refrigerator and freezer units, which go by many other names, were in use for almost 40 years prior to the common home models. They used gas systems such as anhydrous ammonia (R-717) or sulfur dioxide (R-764), which occasionally leaked, making them unsafe for home use and industrial purposes. Practical household refrigerators were introduced in 1915 and gained wider acceptance in the United States in the 1930s as prices fell and non-toxic, non-flammable synthetic refrigerants such as Freon-12® (R-12) were introduced. However, R-12 damaged the ozone layer, causing governments to issue a ban on its use in new refrigerators and air-conditioning systems in 1994. The less harmful replacement for R-12, R-134a (tetrafluoroethane), has been in common use since 1990, but R-12 is still found in many old systems today.

4 Answers 4



"Modelling indicates insignificant ozone depletion potential, a significant global warming potential, and negligible acidification potential." reference One gram of R-134a has the same global warming effect as 1.41 kilograms of CO2, while one gram of R-12 is similar to 8.5 kilograms of CO2. reference


According to the EPA, the LC50 (lethal concentration for 50% of tests) for rats is >500,000 ppm for R-134a compared to 760,000 ppm for R-12, which doesn't seem much different. They're short term exposure limit is slightly different with R-134a at 75,000 ppm and 50,000 ppm for R-12. It appears not to concentrate in soil or water since it vaporizes so easily so that is less of a concern than a breathing in near a large leak and general pollution.


It seems that most fridges have between 4 and 6 oz of R-134a in them. I'm not sure how to convert an X ounce spill into a room sized Y into ppm, which makes it difficult to know just how dangerous it really is.

  • Thank you. I am more interested in environmental impacts anyway :)
    – Stockfisch
    Commented Apr 17, 2013 at 8:57
  • @ZachDwiel, Did you submit your post in mid-sentence? It looks like your last comment didn't get finished. Good information so far, though :)
    – Nate
    Commented May 3, 2013 at 3:24
  • Thanks, didn't notice that and don't remember what I was saying there so I just removed it
    – Zach Dwiel
    Commented May 3, 2013 at 12:24

According to Environment Canada both R-12 and R-134a have 0 ozone depletion potential.

However, R-12 has a global warming potential of 2400 CO2eq, while R-134a has a GWP of 1300 CO2eq. These aren't apples to apples comparisons however. R-12 has an atmostpheric lifetime of about 100 years compared to about 14 years for R134a (NOAA). You also really need to need to know the mass efficiency of the refrigerant to get compare their GWP in a meaningful way.

  • Global warming potential is calculated over a certain time period, so the different lifetimes are already taken into account. This means you can compare them.
    – gerrit
    Commented Jan 21, 2020 at 15:20

Modern A/C and Fridge are built with R134a, R410a and R600a

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    Welcome to Sustainable Living! Thank you for your answer, but could you please elaborate on this? Do you know what impact the mentioned substances have on climate change or ozone depletion?
    – THelper
    Commented Apr 10, 2015 at 5:13

CFCs friendly to ozone layer that protect the earth from UV rays and which do not contributes to the greenhouse effect are being developed. The chlorine free R-134a, a recent finding, is presently replacing R-12

  • 4
    Welcome to Sustainable Living and thank you for your answering. Your answer doesn't seem to provide any new information besides that already given in the question. Do you know how harmful R-12 is compared to R-134a? Or if currently other types of CFCs are used as well (and if so which ones)?
    – THelper
    Commented Jan 19, 2014 at 11:40

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