HFC-23TM Extinguishing Agent for Total Flooding Applications
HFC-23TM is a gaseous
extinguishing agent, which can be used as a replacement for
Halon 1301 in total flooding systems to protect “normally
HFC-23 is efficient on Class A, B and C fires, it is
electrically no-conductive and leaves no residue after
Halogenated extinguishing agents, when in contact with fires
or burning surfaces, generate dcomposition byproducts, which
can be harmful to humans. In order to limit the creation of
toxic byproducts, HFC-23 fire frotection systems are designed
with a maximum discharge time of 10 seconds. The addition of
isoprpenyl l-methyl cyclohexene further reduces the creation
of toxic fumes.
Due to its extremely low toxicity level, HFC-23 is suitable
for protection of “normally occupied” areas, allowing the
designer to apply large safety factors, when the risk requires
high system reliability. Even for the most critical
applications, the design concentration will be far lower than
that which would cause harmful effects to the personnel
present in the protected area. The minimum extinguishing
concentration for n-heptane, determined by the cup-burner
test, is 12% by volume.
The physical properties of HFC-23 allow a fast and homogeneous
distribution in the protected volume, ensuring a rapid and
efficient extinguishment of the fire.
HFC-23 complies with the
requirements of purity for HFC 23 as listed in international
standards for gaseous extinguishing agents.
Although any potential fire risk presents its own particular
complexities, the choice of HFC-23 in a fire protection system
is suitable when:
· an electrial no-conductive gaseous extinguishing agent is
· the clean-up of another media would represent a problem
· to guarantee a high system reliability and, at the same
time, the safety of personnel is of essence
· sub-zero temperatures are encountrad in the protected
Typical examples of hazards where the use of HFC-23 is
suitable are: computer rooms, control rooms, archives,
flammable liquid stores, laboratories, military vehicles,
The Montreal Protocol, which
establishes the actions to control emissions of substances
damaging the ozone layer, banned the manufacture of Halons due
to their high Ozone Depletion Potential (ODP). HFC-23, unlike
Halon 1301 (ODP = 12-16), does not contain Bromine nor
Consequently, it does not deplete the stratospheric ozone
layer (ODP = 0).
Taking into consideration the reduced quantity of this product,
which would be used for very specific applications, then the
Global Warming Potential (GWP) and Atmospheric Lifetime (ALT)
are also acceptable.
HFC-23 does not pose any risk
to humans when used at its recommended desing concentration.
HFC-23 acute toxicity (LC50 for 4 hours = >65%) is far
higher than the normal concentrations of use. Exposure at
lower concentrations for a limited period of time does not
represent a risk to personnel.
Nevertheless, like Halon 1301, exposure to the product at
higher concentrations and for longer periods of time can cause
indisposition, lack of coordination and heart arrhythmia.
The cardiac sensitization is the first evident symptom when
exposed to halogenated extinguishing agents. The NOAEL (No
Observable Adverse Effect Level) and LOAEL (Lowest Observed
Adverse Effect Level) values for HFC-23 are respectively 50%
point @ 1 atm (°C)
pressure @ 25°C (bar)
density @ 25°C (g/ml)
heat of liquid @ 25°C (j/Kg °C)
of vapourization at boiling point point (Kj/Kg)