HFC-23TM Extinguishing Agent for Total Flooding Applications
HIGHLIGHTS
HFC-23TM is a gaseous extinguishing agent, which can be used as
a replacement for Halon 1301 in total flooding systems to
protect “normally occupied” areas.
HFC-23 is efficient on Class A, B and C fires, it is
electrically no-conductive and leaves no residue after discharge.
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.
Use
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
required
· 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
volume.
Typical examples of hazards where the use of HFC-23 is
suitable are: computer rooms, control rooms, archives,
flammable liquid stores, laboratories, military vehicles,
telecommunications system.
Environmental
impact
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 Chlorine.
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.
Toxicity
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%
and 50%.
HFC-23 Physical
Properties
1301
HFC-23
Halon 1301
Molecular
weight
70.01
148.93
Boiling
point @ 1 atm (°C)
-
82.2
-
57.8
Critical
temperature (°C)
25.9
67
Critical
Pressure (bar)
48.36
39.6
Critical
density (Kg./m3)
525
745
Vapour
pressure @ 25°C (bar)
47.29
16.20
Liquid
density @ 25°C (g/ml)
0.67
1.57
Freezing
point (°C)
-155.2
-168
Specific
heat of liquid @ 25°C (j/Kg °C)
1,549
910
Heat
of vapourization at boiling point point (Kj/Kg)
Gielle Srl - Bureaux Via R. Ferri 32 Z.I. - 70022 Altamura (Ba) Italy
Tel +39 0803118998 - Fax + 39 0803101309
E-mail: info@gielle.it
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