Solstice yf

Solstice® yf Refrigerant

Solstice yf refrigerant is a near drop-in replacement for R-134a in automobile air conditioning applications. Solstice yf is helping automakers around the world comply with EU low GWP requirements.

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Fact Sheet

Solstice yf refrigerant Developed for auto air conditioning

Environmentally preferred

Comprehensively tested



HFO Describes an organic fluorine compound called hydrofluoroolefin
1234 Stands for a specific compound:

1 = one double bond

2 = carbon atoms

3 = hydrogens atoms

4 = fluorine atoms

yf Denominates the specific isomer (position of the fluorine atoms)
MAC Directive Starting in January 2011, all new vehicle types must have an air conditioning refrigerant with a global warming potential (GWP) below 150. From 2017 on, this will apply to all new vehicles. This is based on the MAC Directive (2006/40/EG), passed in July 2006.
Development Honeywell and DuPont, in a joint development agreement, have developed a new low global warming potential refrigerant to replace R-134a. They are commercializing the product separately. Honeywell is selling the product under the brand name Solstice® yf refrigerant.
Environmental Solstice yf refrigerant has a GWP of
Approval Solstice yf refrigerant can be used in in Europe, Japan, Korea, China and the U.S. Under the ECE Agreement, Solstice yf refrigerant is also approved in Germany.

Solstice yf refrigerant is registered under the EU chemical regulation REACH, and is included in the U.S. E.P.A.’s SNAP Program (Significant New Alternatives Policy). With this program, the EPA evaluates new and improved substances that replace ozone-depleting substances.

Time of Adoption Car manufacturers will receive the product according to their commitments. Supplies will increase once the production capacity is further extended.
Quantity About 600 grams in modern air conditioning equipment; refill in automotive lifecycle, if necessary.
Scientific Studies Honeywell ensures that all products undergo intense testing both internally and externally, especially during the development phase.

SAE International – the international Society of Automotive Engineers with about 133,000 engineers and technicians – has tested Solstice yf refrigerant for five years in their Cooperative Research Program. Eighteen international, independent scientific institutions and 15 international car manufacturers and component suppliers have participated in this program.These industry participants include: Audi, BMW, Chrysler, Daimler, Fiat, Ford/Volvo, GM/Opel, Honda, Porsche, PSA, Renault, Jaguar/Land Rover, Toyota and VW, as well as Conti Tech, Delphi, Denso, DuPont, Freudenberg, Goodyear, Maflow, Valeo and Visteon.

SAE has concluded that Solstice yf refrigerant is safe for use in automobiles.

Crash Tests The automotive manufacturers and component suppliers have tested Solstice yf refrigerant in detail during the SAE Cooperative Research Program. They have modern testing facilities and broad experience in conducting these tests.

Two examples:
Fiat has conducted a crash test with Solstice yf refrigerant with a Fiat 500 at 65 km/h (in accordance with EuroNCAP Protocol).

  • There was no fire and no excursion of toxic materials.

Peugeot has conducted a crash test with Solstice yf refrigerant in a Peugeot 308 at 56 km/h (in accordance to ECE 94). The engine had been running for a long time and was particularly hot.

  • There was no fire and no excursion of toxic materials.
Safety Note: now there are two classes under 1272/2008:Category Criteria

  • Gases, which at 20°C and a standard pressure of 101,3 kPa:
    • are ignitable when in a mixture of 13% or less by volume in air; or
    • have a flammable range with air of at least 12 percentage points regardless of the lower flammable limit.
  • Gases, other than those of Category 1, which, at 20°C and a standard pressure of 101,3 kPa, have a flammable range while mixed in air.

Class 1 is extremely flammable and Class 2 is flammable

Tests under real-life conditions have shown that the product does not ignite on surfaces up to 800 degrees Celsius. The auto ignition temperature is also established using a test protocol. It is set at 405 degrees Celsius.

Environmental Impact

Solstice yf refrigerant A refrigerant that has been specifically developed for mobile air conditioning in vehicles. It is reliable, has undergone intensive testing, and is energy and cost efficient.

GWP The GWP (Global Warming Potential) indicates how much a material can contribute to global warming compared to CO2.
Solstice yf refrigerant has an ultra low global warming effect. The GWP is <1 - significantly below the EU threshold of 150.

Directives and Regulations in the EU 1907/2006/EG (REACH; Category 1000+ p.a.)

Guidelines for Testing of Chemicals

Possible Environmental Impact of Refrigerants Environmental impact generally occurs when the product leaks from the equipment.
Solstice yf refrigerant has the lowest lifecycle climate performance compared to CO2 and HFC-134a, regardless of region. Calculations were made based on model tests for climates in Phoenix, Arizona; Frankfurt, Germany; Tokyo, Japan; and Athens, Greece. Results were presented by the JAMA-JAPIA consortium at the 2008 SAE Alternative Refrigerant Systems Symposium in Phoenix, Arizona in June 2008.

Emissions Similar to all other refrigerants – no matter whether they are natural or synthetic – it is possible that Solstice yf refrigerant can emit from equipment. These emissions would have an impact on global warming.

There is a distinction between direct emissions, those caused by leaks, and indirect emissions – those caused by energy consumption when the equipment runs with the refrigerant. This would be, for example, the amount of fuel used to run the air conditioning system.

Direct Emissions Direct emissions via leakages in the equipment have been minimized as part of the F-Gas Regulation. High quality and safety standards during production and across the whole value chain have tremendously improved. Containment and disposal of Solstice yf refrigerant also avoids subsequent emissions. In case of an emission, the impact will be very small – due to the GWP of <1, compared to 1430 for R-134a currently in use.

Indirect Emissions Using Solstice yf refrigerant will have a positive impact on indirect emissions, because the fuel consumption will be lower than with other alternatives.

Global Warming Potential Solstice yf refrigerant has a GWP of <1. This is an ultra-low GWP and well below the threshold of the EU MAC Directive (150).
Solstice yf refrigerant can be recovered and reused by properly trained technicians.

Environmental Characteristics Solstice yf refrigerant reacts in the atmosphere via natural processes. In connection with hydroxy radicals (OH radicals) – products that play an important role in reducing air contamination – trifluoric acid (TFA), hydrofluoric acid (HF) and CO2 can be formed. The levels generated from the use of Solstice yf refrigerant in MAC are not expected to raise concerns.

TFA TFA is a natural material that exists in large quantities in the ocean. It stays stable under normal conditions.
The use of Solstice yf refrigerant in MAC is not expected to result in a significant increase in TFA levels, and is expected to be substantially below the Predicted No Observed Effect Concentration (NOEC) thresholds.

HF HF will be washed out of the atmosphere and reacts with calcium sulfate (gypsum) to form calcium fluoride (very stable) and sulphuric acid (dissolves in water).

CO2 The CO2 quantities are very low. CO2 degrades via photosynthesis and the carbon cycle.

Development Milestones

Date Major Milestones
16 September 1987 The signatory states of the UN sign the “Montreal Protocol”. It aims to prevent emissions that harm the earth’s ozone layer.
1 January 1989 The “Montreal Protocol” comes into effect.

11 December 1997 The signatory states of the UN adopt the “Kyoto Protocol”. Many industrial nations commit themselves to reduce emissions of greenhouse gases until 2012 by 5.2 percent below 1990’s level.

8 March 2000 The EU Commission’s European Climate Change Program intensifies the efforts to implement the “Kyoto Protocol”. Working groups discuss options, auto vehicle air conditioning comes into focus.
10 October 2000 The EU Environment Council requests from the EU-Commission to consider measures to reduce emissions of F-Gases (fluorinated greenhouse gases) in auto vehicle air conditioning.
2003 The European Commission approves HFC-152a, R744 and other refrigerants as possible new refrigerants for motor vehicle air conditioning.
16 February 2006 Honeywell presents new, climate-friendly refrigerants.
17 May 2006 The EU directive on air conditioning systems in motor vehicles (2006/40/EG, “MAC-directive”) imposes strict requirements on refrigerants applied. Only refrigerants with a Global Warming Potential (GWP) of less than 150 will be approved for use in mobile systems.
4 July 2006 The EU F-Gas Regulation (EU regulation no. 842/2006) and the MAC-directive of the European Parliament and Council on emissions of F-Gases in auto vehicle air conditioning and on amending directive 70/156/EWG come into effect.
13 February 2008 Honeywell and DuPont present the new and market-ready Solstice yf refrigerant at the annual VDA “Alternative Refrigerant Winter Meeting”.
1 December 2008 The registration process of Honeywell’s new low global warming potential refrigerant for REACH begins. REACH, the new EU chemicals regulation, requires that chemical substances on their own and in preparations have to be registered to the European Chemicals Agency (ECHA).
8 December 2008 Honeywell’s low-global-warming-potential refrigerant is deemed acceptable for the use in automobiles by the renowned SAE’s (International Society of Automobile Engineers) International Cooperative Research Program for use in vehicles: “… offering greatest potential to meet environmental and consumer needs”.
1 January 2009 After intensive testing of R744, SAE’s International Cooperative Research Program prioritizes Honeywell’s new low global warming potential refrigerant over R744 as the refrigerant for practical use in vehicles.
28 May 2009 The German Association of the Automotive Industry (VDA) demands a global standard for refrigerants.
4 August 2009 Honeywell’s new low global warming potential refrigerant is intensively tested by the Japanese Ministries of Health, Labour and Welfare, Economy, Trade and Industry and of the Environment and approved for practical use.
13 October 2009 The US Environmental Protection Agency (EPA) accepts Honeywell’s new low global warming potential refrigerant in its SNAP-program for use as low GWP-refrigerant in auto vehicle air conditioning.
5 January 2010 The European Patent Office grants Honeywell the patent for the new low-GWP refrigerant for auto vehicle air conditioning.
20 May 2010 Honeywell and DuPont announce a joint venture to manufacture the new low GWP refrigerant.
23 July 2010 GM chooses to use Solstice yf refrigerant in cars of its U.S. brands Cadillac, Chevrolet, Buick and GMC from 2013 on.
28 February 2011 EPA approves Honeywell’s new low global warming potential refrigerant for use in auto vehicle air conditioning. EPA’s SNAP report criticizes the tests conducted by the German Bundesanstalt für Materialforschung und -prüfung BAM (Federal Institute for Materials Research and Testing) for not fully revealing the test set-up. Thus, tests cannot really be judged scientifically, EPA notes.

Occupational Health and Safety

Solstice yf refrigerant is a safe refrigerant for use in vehicle air conditioning systems. Numerous laws and other regulations are in place to ensure that when properly used these substances pose no threat to people and the environment.

During development of the product, Honeywell initiated detailed studies that yielded data for the regulatory requirement submissions for chemical substances. Solstice yf refrigerant is already registered as a refrigerant according to the EU REACH regulation. It is approved for use in Japan, South Korea, China and the U.S.

Applied Amounts In vehicles: about 600 grams

In car repair shops: usually 10 kg cylinders

Tests for Regulatory Reviews 1907/2006/EC (REACH; category 1000+ p.a.)

67/548/ECC (Dangerous Substances Directive)

Guidelines of The Organization for Economic Cooperation and Development

European regulation on how to handle potentially explosive materials

Safety tests performed by the Society of Automotive Engineers (SAE)

Additional Tests Fiat tested Solstice yf refrigerant in a crash test with the Fiat 500, performed at 40 mph (according to EuroNCAP Protocol).

Peugeot tested Solstice yf refrigerant in a crash test with the Peugeot 308, performed at 35 mph (according to ECE 94). The test was conducted at a high temperature.

In both tests, no fires occurred and no toxic substances were released.

Acceptable Exposure Limits for Solstice yf refrigerant in Daily Use (8 Hour Time Weighted Average) Acceptable limits: 500 ppm (parts per million) in the workplace (according to the American Industrial Hygienists Association).

Factual Exposure: vehicle: <1 ppm, stationary place: <1 ppm.

Classifications Toxicity Screening: Class A (lowest toxicity in accordance with the classification of American Society of Heating, Refrigerating and Air-Conditioning Engineers, ASHRAE).

H220: (Extremely flammable, but non-toxic according to Regulation (CLP) No. 1272/2008, which replaces 67/548/EEC and introduces two categories of flammability based on the Lower Flammability Limit (<13%) that categorizes gaseous substances A2L (moderately flammable according to ISO 817).

Flammability The EU requirements for the classification of gases (Regulation on Classification, Labeling and Packaging of Substances and Mixtures of 30.11.2010, Regulation (EU) No. 1272/2008) designates Solstice yf refrigerant as “extremely flammable”. This classification is solely based on the lower flammability limit and ignores other important parameters such as ignition energy, heat of combustion and flame propagation rate.
The energy required to ignite Solstice yf refrigerant is 5 to 10,000 mJ (Millijoule). By comparison:

  • Gasoline ignites at 0.2 mJ.
  • Spark plugs need a minimum energy of approximately 40 mJ to ignite fuel.
  • Auto ignition temperature of air/refrigerant mixture: 405 degrees Celsius.
  • In tests no ignition was recorded on contact with hot surfaces with temperatures of up to 800 degrees Celsius.
Decomposition Substance: Hydrofluoric Acid Independent, global testing laboratories have conducted comprehensive tests on Solstice yf refrigerant. Based upon the results of these tests, SAE has concluded that Solstice yf refrigerant is safe for use in mobile air conditioning.

The risk associated with the formation of hydrofluoric acid is similar to that of the current refrigerant, R-134a. Given the many years of safe use of HFC-134a in automobile air conditioning and the lack of any published medical reports indicating exposures to HF, it has been concluded that Solstice yf refrigerant is safe for use in mobile air conditioning.

(Re)fill, Maintenance and Disposal High quality as well as safety standards assure a safe supply chain exclusively to car manufacturers, suppliers and qualified specialized companies. It is not distributed to private users.

A/C training prepared by the German Federation for Motor Trades, according to regulation EG No. 307/2008, provides for the safe and proper use of cooling agents.

Guidelines for the application in garages and specialized companies have been developed by third parties.

Trained garage personnel will recover Solstice yf refrigerant for recycling or final disposal.

The Facts Download
Product Brochure Download
Fact Sheets
Solstice yf info Download
Solstice yf environmental info Download
Solstice yf Occupational Health and Safety info Download
Solstice yf – A Better Choice Fact Sheet (OEMs) Download
Solstice yf – A Better Choice Fact Sheet (Aftermarket) Download
Major Milestones in the Development of HFO-1234yf Download
Use and Handling Guidelines
Solstice yf Use and Handling Guidelines Download
Position Paper on F-Gas Regulation Download
Paper on Energy Efficiency in Domestic Appliances & Lighting Conference Ruediger Fleischer Download
Paper on International Symposium on Non-CO2 Greenhouse Gases – Shankland and Singh Download
State of the Industry with Ward Atkinson April 2009 Download
EPA Presentation – MAC Industry Actions, Stephen Andersen, December 2008 Download
Presentation – Honeywell and DuPont – SAE World Congress, April 2008 Download
Chart of greenhouse emissions from refrigerant use Download