1,1,1,2-Tetrafluoroethane

1,1,1,2-Tetrafluoroethane

IUPAC name [hide]

1,1,1,2-Tetrafluoroethane

Other names[hide]

Genetron 134aHFA-134aHFC-134a

R-134aSuva 134aNorflurane

Identifiers

CAS number 811-97-2 

ChemSpider 12577

UNII DH9E53K1Y8

EC number 212-377-0

RTECS number KI8842500

SMILES  [show]

InChI  [show]

InChI key LVGUZGTVOIAKKC-UHFFFAOYAU

Properties

Molecular formula C2H2F4

Molar mass 102.03 g/mol

Appearance Colorless gas

Density 0.00425 g/cm³, 4.25 Kg/m³, gas

Melting point -103.3°C (169.85 K)

Boiling point -26.3°C (246.85 K)

Solubility in water 0.15 wt%

HazardsMSDS External MSDS

S-phrases (S2), S23, S24/25, S51

NFPA 704

111

Flash point 250 °C (482 °F)

Related compounds

Related refrigerants DifluoromethanePentafluoroethane

Related compounds

1,1,2,2,2-pentafluoroethane2-Chloro-1,1,1,2-tetrafluoroethane1,1,1-Trichloroethane

Supplementary data pageStructure andproperties n, εr, etc.

Thermodynamicdata

Phase behaviourSolid, liquid, gas

Spectral data UV, IR, NMR, MS

  (what is this?)  (verify)Except where noted otherwise, data are given for materials in

their standard state (at 25   °C, 100   kPa)

Infobox references

1,1,1,2-Tetrafluoroethane, R-134a, Genetron 134a, Suva 134a or HFC-134a, is a haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane), but with less ozone depletion potential. It has the formula CH2FCF3, and a boiling point of −26.3 °C (−15.34 °F).

Uses1,1,1,2-Tetrafluoroethane is an inert gas used primarily as a “high-temperature” refrigerant for domestic refrigeration and automobile air conditioners. These devices began using 1,1,1,2-tetrafluoroethane in the early 1990's as a replacement for the more environmentally-harmful R12,

and retrofit kits are available to convert units that were originally R12-equipped. Other uses include plastic foam blowing, as a cleaning solvent and as a propellant for the delivery of pharmaceuticals (e.g. bronchodilators), gas dusters, and in air driers, for removing the moisture from compressed air. 1,1,1,2-Tetrafluoroethane has also been used to cool computers in some overclocking attempts. It is also commonly used as a propellant for airsoft airguns.

Tetrafluoroethane, when compressed as inside gas duster cans, is a clear liquid which boils when exposed to room temperature (as seen here) and can be extracted from common canned air canisters by simply inverting them during use.

Recently, 1,1,1,2-tetrafluoroethane has been subject to use restrictions due to its contribution to climate change. In the EU, it will be banned as from 2011 in all new cars.[1] The Society of Automotive Engineers (SAE) has proposed 1,1,1,2-tetrafluoroethane (HFC-134a) to be best replaced by a new fluorochemical refrigerant HFO-1234yf (CF3CF=CH2) in automobile air-conditioning systems.[2] California may also prohibit the sale of canned 1,1,1,2-tetrafluoroethane to individuals to avoid non-professional recharge of air conditioners. [3] A ban has been in place in Wisconsin since October 1994 under ATCP 136 prohibiting sales of container sizes holding less than 15 lbs of 1,1,1,2-tetrafluoroethane, but this restriction applies only when the chemical is intended to be a refrigerant.[4] It appears, for example, that it is legal for a person to purchase gas duster containers with any amount of the chemical because in that instance the chemical is neither intended to be a refrigerant [4] nor is HFC-134a included in the § 7671a listing of class I and class II substances.[5]

History

1,1,1,2-Tetrafluoroethane first appeared in the early 1990s as a replacement for dichlorodifluoromethane (R-12), which has ozone depleting properties.[6] 1,1,1,2-Tetrafluoroethane has been atmospherically modeled for its impact on depleting ozone and as a contributor to global warming. Research suggests that over the past 10 years the concentration of 1,1,1,2-tetrafluoroethane has increased significantly in the Earth's atmosphere, with a recent study revealing a doubling in atmospheric concentration between 2001–2004.[7] It has insignificant ozone depletion potential (ozone layer), significant global warming potential (100-yr GWP = 1430)[8] and negligible acidification potential (acid rain).

SafetyContact of 1,1,1,2-tetrafluoroethane with flames or hot surfaces in excess of 250 °C (482 °F) may cause vapor decomposition and the emission of toxic gases including hydrogen fluoride and carbonyl halides.[9] 1,1,1,2-Tetrafluoroethane itself has an LD50 (lethal concentration for 50% of subjects) in rats of 1,500 g/m³, making it relatively non-toxic. However, its gaseous form is denser than air, and will displace air in the lungs. This can result in asphyxiation if excessively inhaled.[10][11]

Aerosol cans containing 1,1,1,2-tetrafluoroethane, when inverted, become effective freeze sprays. Under pressure, 1,1,1,2-tetrafluoroethane is compressed into a liquid, which upon vaporization absorbs a significant amount of thermal energy. As a result, it will greatly lower the temperature of any object it contacts as it evaporates. This can result in frostbite when it contacts skin, as well as blindness upon eye contact.