There are reports that suggest R-1234yf has a global warming potential (GWP) less than 1, even outperforming carbon dioxide:

The study found HFO 1234yf to have a GWP of less than 1. CO2 is considered the baseline with a GWP equal to 1. Earlier studies had calculated the GWP for HFO 1234yf at 4, which is still a 99.7 percent improvement over HFC 134a, the manufacturer noted.

If this is indeed the case, is it safe for the average vehicle owner to just vent it to atmosphere?

Or is there some other EHS gotcha that needs to be kept in mind?

  • Gentlemen (I hope you are all guys). I've cleaned up this thread because the comments are out of hand and provide nothing taking this question forward towards answering. – Pᴀᴜʟsᴛᴇʀ2 Jun 1 '18 at 20:42

TL;DR: R-1234yf is expected to evaporate in the event of a spill

According to the Honeywell material safety data sheet (MSDS), R-1234yf is fairly similar to R-134a, with a few key differences:

  • Unlike R-134a it is extremely flammable, rated F+
  • In the event of an accidental spill, the MSDS states that the product is designed to "evaporate readily", unlike R-134a:

    Environmental precautions :

    • The product evaporates readily.
    • Prevent product from entering drains.

    Methods for cleaning up :

    • Use low-sparking handtools and explosion-proof electrical equipment
    • Allow to evaporate.

    Additional advice :

    • Inform the responsible authorities in case of gas leakage, or of entry into waterways, soil or drains. Pay attention to the spreading of gases especially at ground level (heavier than air) and to the direction of the wind.

A few other considerations:

  • Disposal recommendations center around legislation and packaging/reuse concerns:


    Product : Dispose according to legal requirements.
    Packaging : Legal requirements are to be considered in regard of reuse or disposal of used packaging materials

  • Toxicity is a concern in very high concentrations, which explains the ventilation recommendation

  • Note the caveat in the MSDS:

    The information provided in this Safety Data Sheet is correct to the best of our knowledge, information and belief at the date of its publication. The information given is designed only as a guidance for safe handling, use, processing, storage, transportation, disposal and release and is not to be considered a warranty or quality specification.

  • Clearly this product is not safe for release as the MSDS makes clear : inform the authorities re leakage into atmosphere or entry into waterways or soil. Not only that but it will be another expensive piece of specialist equipment that garages will need to purchase .... So the answer must be no... – Solar Mike Jun 2 '18 at 3:03

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