Use of the ozone-depleting refrigerant, chlorofluorocarbon (CFC)-12, in brand-new motor automobile air conditioning (MVAC) systems finished in the mid-1990s in the joined States. Because 1994, the most usual refrigerant supplied in MVAC systems has been hydrofluorocarbon (HFC)-134a. HFCs space intentionally-made fluorinated greenhouse gases used in the very same applications whereby ozone-depleting substances have actually been used, consisting of motor auto air conditioning. Choose the ozone-depleting substances they replace, many HFCs are potent greenhouse gases with an extremely high worldwide warming potentials (GWPs). In 2012, car manufacturers began the shift to new, climate-friendly alternate refrigerants. Together a result of a July 2015 rulemaking, by design year 2021, the MVAC solution in newly produced light-duty vehicles in the United states will no much longer use HFC-134a.

You are watching: When can hfc 134a become combustible

Significant brand-new Alternatives policy (SNAP) Program’s Significant new Alternatives policy (SNAP) regimen reviews substitutes within a comparative risk framework in a range of commercial sectors that historically used ozone-depleting substances. MVAC systems are one end-use in ~ the refrigeration and air conditioning sector. The SNAP program evaluates and also lists substitutes the reduce overall risk to person health and also the environment considering ozone-depletion potential, worldwide warming potential (GWP), flammability, toxicity, regional air quality, ecosystem effects, and also occupational and consumer health/safety. SNAP list substitutes as acceptable, acceptable topic to use problems or unacceptable. MVAC refrigerants are detailed as either acceptable subject to use conditions or unacceptable.

Retrofitting CFC-12 MVAC systems is also regulated under the SNAP program. Vehicles might only it is in retrofitted with choices approved under SNAP for use as retrofits. HFC-134a is the main refrigerant right now used come retrofit CFC-12 systems. For added information, visit Choosing and Using a Retrofit Refrigerants for a CFC-12 Motor automobile Air Conditioner.

Under SNAP, every flammable refrigerants, except HFC-152a and also HFO-1234yf, are provided as unacceptable for usage in new and retrofit MVAC systems. This has all hydrocarbon refrigerants. Once a refrigerant is provided as unacceptable, its usage is illegal. 

Environmental results of MVAC Refrigerants
MVAC RefrigerantGlobal Warming PotentialOzone Depleting?
CO2  (R-744)1No

CFC-12: an Ozone-Depleting Refrigerant

Ozone depleting refrigerant with a GWP of 10,900Automobile manufacturers began to shift to the non-ozone depleting refrigerant, HFC-134a, through 1992 version year vehicles. Through the 1995 model year, all brand-new vehicles marketed in the United says with wait conditioners used HFC-134a refrigerant. 

The ozone great ozone class The an ar of the stratosphere include the mass of atmospheric ozone. The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth"s surface, in the stratosphere. Depletion the this layer by ozone-depleting substances will certainly lead to greater UVB level (a band of ultraviolet radiation), which in turn will reason increased skin cancers and also cataracts and also potential damage to some marine organisms, plants, and also plastics. is existing 10 to 30 miles above the earth’s surface ar in the stratosphere where it defend us indigenous harmful ultraviolet (UV) radiation. Ozone ns in the environment allows greater levels of UVB to with the Earth"s surface and leads to negative health and environmental effects. These impacts include increases in cataracts, skin cancer, and weakened immune systems. Plant and also animal life, agriculture, and materials prefer plastics and also paints are likewise affected. The stratospheric ozone layer must not be puzzled with ground-level ozone. Ozone is "good increase high, poor nearby." even though that protects us when it is in the stratosphere, ozone in ~ ground level deserve to be harmful to breathe and is a prime ingredient in smog.  

HFC-134a: a Potent Greenhouse Gas

Most usual refrigerant supplied in MVAC systems since the 1990sPotent greenhouse gas v a global warming potential the is 1,430 times that of CO2Use the HFC-134a in MVAC solution accounts for an approximated 24% that total an international HFC consumption. The is the many abundant HFC in the atmosphere. HFC-134a will no much longer be authorized for use in brand-new light-duty vehicles made or sold in the United claims as of version year 2021 together a result of’s July 2015 final rule under SNAP (July 20, 2015, 80 FR 42870).Limited exemption (narrowed usage limit) with MY 2025 for usage of HFC-134a in vehicles destined for usage in nations that execute not have actually infrastructure in location for servicing with other acceptable refrigerants (July 20, 2015, 80 FR 42870).Servicing of present vehicles making use of HFC-134a v HFC-134a will certainly not be affected and will proceed to it is in allowed.

New Climate-Friendly alternative Refrigerants

In the joined States and also globally, many car manufacturers space transitioning come the lower-GWP choices approved by SNAP, defined below. None of these deplete the ozone layer and all have considerably lower effects on the climate system than HFC‑134a.

The breakthrough of MVAC equipment using lower-GWP refrigerants has actually been urged by MVAC refrigerant requirements in Europe, wherein the EU Directive on mobile Air conditioning (MAC Directive) mandates change to a refrigerant with a GWP listed below 150 by January 1, 2017, and in the United states by the ease of access of credits under the my 2017-2025 Light-Duty Greenhouse (LD GHG) preeminence (77 FR 62624, October 15, 2012).

It is crucial for both consumers and technicians come be mindful of these alternate refrigerants, their properties, and also proper servicing procedures. A printable magazine is easily accessible for new climate-friendly motor car air air conditioning refrigerants.’s regulatory requirements for the servicing that MVAC systems apply to all three of these refrigerants.

HFO-1234yf (R-1234yf)

GWP that 4Acceptable, topic to usage conditions, for brand-new passenger cars and light-duty trucks just (March 29, 2011, 76 FR 17488; in march 26, 2012, 77 FR 17344)Mildly flammable (ASHRAE A2L), however can be used safelyModels using HFO-1234yf include: Cadillac XTS, Chevrolet Spark EV, BMW i3 and i8, Chrysler 200, Chrysler 300, evade Challenger, dodge Charger, evade Dart, evade Durango, Jeep Cherokee, Jeep Wrangler, ram 1500, Fiat 500 and 500L, Alfa Romeo 4C, Honda fit EV, Tesla version S, selection Rover, and selection Rover SportRequired use conditions:HFO-1234yf MVAC systems must adhere to every one of the safety needs of SAE J639 (adopted 2011), consisting of requirements for a flammable refrigerant warning label, high-pressure compressor cutoff switch and pressure relief devices, and unique fittings. For relationships with refrigerant containers for use in expert servicing, usage fittings must be continual with SAE J2844 (revised October 2011).Manufacturers have to conduct failure Mode and Effect analysis (FMEA) as provided in SAE J1739 (adopted 2009). Manufacturers have to keep the FMEA on document for at least three year from the date of creation.

See more: Does Metronidazole Need To Be Refrigerated, Left Medication Out! Desperately Need Help!

Carbon Dioxide (CO2, R-744)

GWP of 1Acceptable, topic to use conditions, for brand-new vehicles only (June 6, 2012, 77 FR 33315)Operates at 5 come 10 times greater pressure than other MVAC systemsUnder advancement by number of foreign car manufacturersRequired use conditions:Engineering methods and/or mitigation gadgets shall be included such the in the occasion of refrigerant leaks the resulting CO2 concentrations carry out not exceed the STEL that 30,000 ppm average over 15 minute in the passenger cost-free space and the ceiling limit of 40,000 ppm in the passenger breathing zone.OEMs have to keep documents of the tests performed because that a minimum duration of 3 years demonstrating that CO2 refrigerant levels do not exceed the STEL of 30,000 ppm averaged over 15 minutes in the passenger totally free space, and the ceiling limit of 40,000 ppm in the breath zone.The usage of CO2 in MVAC systems should adhere to the standard conditions identified in SAE typical J639 ( 2012b).

HFC-152a (R-152a)

GWP the 124Acceptable, topic to use conditions, for brand-new vehicles only (June 12, 2008, 73 FR 33304)Moderately flammable (ASHRAE A2), but can be supplied safelyMay be pursued by automobile manufacturers in the futureRequired use conditions:Engineering strategies and/or devices shall be included into the system such that foreseeable leaks right into the passenger compartment perform not an outcome in R-152a concentrations of 3.7% v/v or above in any component of the complimentary space1 inside the passenger compartment for more than 15 seconds once the vehicle ignition is onManufacturers must adhere to every the security requirements noted in the SAE traditional J639, including distinctive fittings and also a flammable refrigerant warning label and also SAE traditional J2773, “Refrigerant Guidelines for Safety and Risk analysis for usage in mobile Air air conditioning Systems.”