Safety
At high temperatures, heptafluoropropane will decompose and produce
hydrogen fluoride. 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, 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 is able to reduce the amount of
hydrogen fluoride. Contact with liquid HFC-227ea may cause
frostbite.
also called heptafluoropropane, HFC-227ea (ISO name), HFC-227 or
FM200, as well as apaflurane (INN), is a colourless, odourless
gaseous halocarbon commonly used as a gaseous fire suppression
agent.
Chemistry
Its chemical formula is CF3-CHF-CF3, or C3HF7. With a boiling point
of −16.4 °C, it is a gas at room temperature. It is slightly
soluble in water (260 mg/L).
Use
HFC-227ea finds use in fire suppression systems in data processing
and telecommunication facilities, and in protection of many
flammable liquids and gases. HFC-227ea falls in the category of
Clean Agents 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
level 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.[citation needed] In
addition, HFC-227ea leaves no residue on valuable equipment after
discharge.[2]
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.
Climate change considerations
Heptafluoropropane (HFC-227ea) contributes to climate change. It
has a global warming potential of 3,220.[3]
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).[4]
