Pentafluoroethane

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ImageFileL1 = Pentafluoroethane.png ImageSizeL1 = 120px
ImageFileR1 = 1,1,1,2,2-Pentafluoroethane.svg
ImageSizeR1 = 150px
IUPACName = Pentafluoroethane
OtherNames = 1,1,1,2,2-Pentafluoroethane, Genetron HFC 125, Khladon 125, Suva 125, Freon 125, Fc-125, R-125
Section1 = Chembox Identifiers
CASNo = 354-33-6
EINECS = 206-557-8
PubChem = 9633
SMILES = FC(F)C(F)(F)F
InChI = 1/C2HF5/c3-1(4)2(5,6)7/h1H
Section2 = Chembox Properties
Formula = C₂HF₅
MolarMass = 120.02 g/mol
Appearance = Colourless gas
Density = 1.24 g/cm³
MeltingPt = -103.0 °C
BoilingPt = -48.5 °C
Solubility =
Section7 = Chembox Hazards
MainHazards =
FlashPt =
Autoignition =

Pentafluoroethane, also called 1,1,1,2,2-pentafluoroethane, HFC-125, or R-125, is a refrigerant that has zero ozone depletion potential. It has the formula CF₃CHF₂.

Pentafluoroethane in an azeotropic mixture with difluoromethane is known as R-410A, a common replacement for various chlorofluorocarbons (aka "Freon") in new refrigerant systems.

Although it has zero ozone depletion potential, it has high global warming potential, 3400 times that of carbon dioxide, based on a 100-year time frame [http://www.maine.gov/dep/air/emissions/ghg-equiv.htm] .

Pentafluoroethane is also used as a fire suppression agent in fire suppression systems.

Fire suppression systems

HFC-125 can be used in clean agent fire suppression systems. The HFC-125 clean agent is stored in a pressurized container and introduced into the hazard as a gas. The agent is odorless, colorless, electrically non-conductive, non-corrosive, and leaves no residue. It is used in occupied enclosed areas that contain high-value assets.

HFC-125 suppresses fire by absorbing heat energy at its molecular level faster than the heat can be generated, so the fire cannot sustain itself. It also forms free radicals to chemically interfere with the chain reaction of the combustion process. This makes it a highly effective fire fighting agent that is safe for people and causes no damage to equipment.

When introduced to the market HFC-125 was not considered safe for use in occupied spaces. The US EPA SNAP (Significant New Alternative Policy) listing reflected this. Following the introduction and acceptance of the PBPK model in the NFPA standard NFPA 2001 Standard on Clean Agent Fire Extinguishing Systems 2004 Edition, the restriction was relaxed and now HFC-125 can be used in occupied hazards. Generally, class B (flammable liquid) hazards require concentrations that exceed the agent NOAEL so extra precautions must be taken to avoid prolonged exposure to the agent.

References

EPA site on hazards: http://www.epa.gov/iris/subst/0683.htm

External links

* [http://ptcl.chem.ox.ac.uk/MSDS/PE/1,1,1,2,2-pentafluoroethane.html Safety MSDS data]