1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227ea (ISO name), HFC-227 or FM-200, as well as apaflurane (INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent.
Its chemical formula is CF-CHF-CF, or CHF. With a boiling point of −16.4 °C, it is a gas at room temperature. It is slightly soluble in water (260 mg/L).
HFC-227ea is used in fire suppression systems that protect data processing and telecommunication facilities, and in fire suppression of many flammable liquids and gases. HFC-227ea is categorized as a Clean Agent and is governed by NFPA 2001 - Standard for Clean Agent Fire Extinguishing Systems. Effective fire suppression requires introducing a concentration of the HFC-227ea agent between 6.25% and 9% depending on the hazard being suppressed. Its NOAEL for cardiac sensitization is 9%. The United States Environmental Protection Agency allows concentration of 9% volume in occupied spaces without mandated egress time, or up to 10.5% for a limited time. Most fire suppression systems are designed to provide concentration of 6.25-9%.
The HFC-227ea fire suppression agent was the first non-ozone-depleting replacement for Halon 1301. In addition, HFC-227ea leaves no residue on valuable equipment after discharge.[1]
HFC-227ea contains no chlorine or bromine atoms, presenting no ozone depletion effect. Its atmospheric lifetime is approximated between 31 and 42 years. It leaves no residue or oily deposits and can be removed by ventilation of the affected space.
As an aerosol propellant, HFC-227ea is used in pharmaceutical metered dose inhalers such as those used for dispensing asthma medication.
At high temperatures, heptafluoropropane will decompose and produce hydrogen fluoride. The decomposition produces a sharp, pungent odour, which can be perceived in concentrations far below a dangerous level. Other decomposition products include carbonyl fluoride, carbon monoxide and carbon dioxide. Prior to re-entry of a room where HFC-227ea system has been activated to suppress a fire, the atmosphere should be tested. An Acid Scavenging Additive added to heptafluoropropane reduces the amount of hydrogen fluoride. Contact with liquid HFC-227ea may cause frostbite.
Heptafluoropropane (HFC-227ea) contributes to climate change. It has a global warming potential (GWP) of 3,220 over 100 years.[2]
Due to its high GWP, the HFC-227ea has been included in the list of controlled substances of the Montreal Protocol (2016 Kigali amendment, in effect in January 2019).[3] Under EU regulations, production, imports and sales of HFC-227ea in spray cans such as freeze sprays or dusters have been prohibited since 2014, as the GWP is over the limit of 150 for these applications.[4] [5] [6]
Other fire suppression agents: