Pentafluoroethane is a

fluorocarbon Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often have distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Several fluorocarbons and their derivatives are ...

with the formula CF₃CHF₂. Pentafluoroethane is currently used as a

refrigerant A refrigerant is a working fluid used in the cooling, heating, or reverse cooling/heating cycles of air conditioning systems and heat pumps, where they undergo a repeated phase transition from a liquid to a gas and back again. Refrigerants are ...

(known as R-125) and also used as a

fire suppression agent A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants m ...

fire suppression system Fire suppression systems are used to extinguish, control, or in some cases, entirely prevent fires from spreading or occurring. Fire suppression systems have an incredibly large variety of applications, and as such, there are many different types ...

s. Pentafluoroethane does not deplete ozone so it has replaced earlier fluorinated chemicals that did. However while it has zero

ozone depletion potential The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for examp ...

, it has high

global warming potential Global warming potential (GWP) is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, relative to carbon dioxide (). It is expressed as a multiple of warming caused by the same mass of carbon dioxide ( ...

, reported by the

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on De ...

(EPA) as 3450 times that of carbon dioxide.

Refrigerant

Pentafluoroethane in a near

azeotropic mixture An azeotrope () or a constant heating point mixture is a mixture of two or more liquids whose proportions cannot be changed by simple distillation.Moore, Walter J. ''Physical Chemistry'', 3rd e Prentice-Hall 1962, pp. 140–142 This happens beca ...

with

difluoromethane Difluoromethane, also called HFC-32 is an organofluorine compound with the formula CH2F2. It is a colorless gas that is used as a refrigerant. Synthesis Difluoromethane is produced by the reaction of dichloromethane and hydrogen fluoride (H ...

is known as

R-410A R-410A is a refrigerant fluid used in air conditioning and heat pump applications. It is a zeotropic but near- azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125). R-410A is sold under the tra ...

, a common replacement for various

chlorofluorocarbon Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly Halogenation, halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F). They are produced as volatility (chemistry), volat ...

s (commonly known as ''Freon'') in new refrigerant systems.

Fire suppression systems

HFC-125 (ECARO-25 / FE-25 / NAF S 125) is a

gaseous fire suppression Gaseous fire suppression, also called clean agent fire suppression, is the use of inert gases and chemical agents to extinguish a fire. These agents are governed by the National Fire Protection Association (NFPA) Standard for Clean Agent Fire Ex ...

agent which can be used in clean agent fire suppression systems. In addition, HFC-125 leaves no residue on valuable equipment and material after discharge. It is generally used in situations where water from a fire sprinkler would damage expensive equipment, or where water-based fire protection is impractical, such as museums, banks, clean rooms and hospitals. 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. HFC-125 is considered a Clean Agent and is therefore included in the

National Fire Protection Association The National Fire Protection Association (NFPA) is a U.S.-based international nonprofit organization devoted to eliminating death, injury, property damage, and economic loss due to fire, electrical, and related hazards. , the NFPA claims to have 5 ...

's 2001 - Standard for Clean Agent Fire Extinguishing Systems.

Environmental impact

HFC-125 is a non-ozone depleting replacement for

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

- or

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

-containing chemicals such as

Halon 1301 Bromotrifluoromethane, commonly referred to by the code numbers Halon 1301, R13B1, Halon 13B1 or BTM, is an organic halide with the chemical formula carbon, Cbromine, Brfluorine, F3. It is used for gaseous fire suppression as a far less toxic alte ...

. Due to its global warming potential (GWP) of 3500 times that of CO₂ and

atmospheric lifetime Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...

of 29 years, it is included in the list of controlled substances of the

Montreal Protocol The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 ...

.Montreal Protocol Section 1.1. including 2016 Kigali amendment (in effect in 2019) When introduced to the market HFC-125 was not considered safe for use in occupied spaces. The US EP
Significant New Alternative Policy
(SNAP) listing reflected this. Following the introduction and acceptance of the PBPK model in the NFPA standard 2001 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's

no-observed-adverse-effect level The no-observed-adverse-effect level (NOAEL) denotes the level of exposure of an organism, found by experiment or observation, at which there is no biologically or statistically significant increase in the frequency or severity of any adverse effe ...

(NOAEL) so extra precautions must be taken to avoid prolonged exposure to the agent. 407-gas

At high temperatures, pentafluoroethane will decompose and produce

hydrogen fluoride Hydrogen fluoride (fluorane) is an Inorganic chemistry, inorganic compound with chemical formula . It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluori ...

. This is observable as presence of sharp, pungent odour, which can be perceived in concentrations far below a dangerous level. Other decomposition products include

carbonyl fluoride Carbonyl fluoride is a chemical compound with the formula . It is a carbon oxohalide. This gas, like its analog phosgene, is colourless and highly toxic. The molecule is planar with ''C''2v symmetry, bond lengths of 1.174 Å (C=O) and 1.312 Å ( ...

carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

and

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

. Prior to re-entry of a room where HFC-125 system has been activated to suppress a fire, the atmosphere should be tested. A
Acid Scavenging Additive
added to pentafluoroethane is able to reduce the amount of hydrogen fluoride.

Brands

ECARO-25 is a registered

trademark A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...

of Fike Corporation. FE-25 is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates. NAF S 125 (HFC-125 plus Acid Scavenging Additive) is a trademark of Safety Hi-Tech.

References

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External links

Safety MSDS data
{{DEFAULTSORT:Pentafluoroethane Fluoroalkanes Fire suppression agents Hydrofluorocarbons