FIRE EXTINGUISHING COMPOSITIONS

COMPOSITIONS D'EXTINCTION D'INCENDIE

English Abstract

QM 35986
Abstract:
Fire Extinguishing Compositions
A fire extinguishing composition comprising at least
one fire extinguishing compound selected from the
isomers of dichloropentafluoropropane, a fire
extinguishing device containing said composition and a
method of extinguishing a fire using said composition.

Claims

QM 35986
- 5 -
Claims:
1. A fire extinguishing composition comprising at
least one fire extinguishing compound selected from the
isomers of dichloropentafluoropropane.
2. A fire extinguishing composition as claimed in
claim 1 wherein the at least one fire extinguishing
compound selected from the isomers of
dichloropentafluoropropane comprises at least a major
proportion of the 1,1-dichloro-2,2,3,3,3-pentafluoro-
propane isomer.
3. A fire extinguishing composition as claimed in claim
2 wherein the 1,1-dichloro-2,2,3,3,3-pentafluoropropane
isomer constitutes at least 50 % by weight of the at
least one fire extinguishing compound selected from the
isomers of dichloropentafluoropropane.
4. A fire extinguishing composition as claimed in any
one of the preceding claims which further comprises at
least one other fire extinguishing compound.
5. A fire extinguishing composition as claimed in any
one of the preceding claims which further comprises at
least one coadjuvant agent having A boiling point below
0 °C.
6. A method of extinguishing a fire which method
comprises administering to said fire an effective
amount of a fire extinguishing composition comprising
at least one fire extinguishing compound selected from
the isomers of dichloropentafluoropropane.
7. A method of extinguishing a fire as claimed in claim
6 wherein the at least one fire extinguishing compound
selected from the isomers of dichloropentafluoropropane
contained in the fire extinguishing composition
administered to the fire comprises at least a major

- 6 -
proportion of the 1,1-dichloro-2,2,3,3,3-pentafluoro-
propane isomer.
8. A method as claimed in claim 7 wherein the
1,1-dichloro-2,2,3,3,3-pentafluoropropane isomer
constitutes at least 50 % by weight of the at least one
fire extinguishing compound selected from the isomers
of dichloropentafluoropropane contained in the fire
extinguishing composition administered to the fire.
9. A fire extinguishing device containing a fire
extinguishing composition as claimed in any one of
claims 1 to 5.
10. A fire extinguishing device as claimed in claim 9
containing a gaseous propellant to effect delivery of
the said fire extinguishing composition from the fire
extinguishing device.
11. A fire extinguishing device as claimed in claim 10
wherein the gaseous propellant is carbon dioxide.

Description

2 ~ 7~J
- 1 - QM 35986
FIRE EXTINGUISHING COMPOSITIONS
The present invention relates to fire extinguishin~
compositions, to fire extinguishing devices containing
such compositions and to a method of extinguishing a
fire using such compositions.
In view of the concern surrounding possible damage
to the ozone layer by certain halocarbons, a need has
arisen to find alternative fire e~tinguishing
compositions. ~hile fire extinguishing compositions
known in the art provide effective fire extinguishing
performance, the use of such compositions may have a
destructive effect on the ozone layer.
The problem which the present invention sets out
to solve is, therefore, to provide a fire extinguishing
composition which exhibits good fire extinguishing
performance and is relativel~ ozone benign.
According to the first aspect of the present
invention there is provided a fire extinguishing
composition comprising at least one fire extin~uishing
compound selected from the isomers of
dichloropentafluoroProPane.
According to the second aspect of the present
invention there is provided a fire extinguishiny device
containing the fire e~tinguishing composition of the
first aspect.
According to a third aspect of the present
invention there is provided a method of extinguishing a
fire which method comprises administering to said fire
an effective amount of a fire extinguishing composition
comprising at least one fire extinguishing compound
selected from the isomers of
dichloropentafluoropropane.

2 ~ 7
.
-- 2
The isomers of dichloropentafluoropropane are
those having the empirical formula C3F5C12H, such as
1,1-dichloro-2,2,3,3,3-pentafluoropropane and
1!3-dichloro-1,2,2,3,3-pentafluoropropane. The fire
extinguishing composition may comprise a sin~le isomer
of dichloropentafluoropropane or a mixture of such
isomers. A particularly preferred isomer is
1,1-dichloro-2,2,3,3,3-pentafluoropropane and,
accordingl~, in a preferred fire extin~uishin~
composition of the invention the at least one fire
extinguishing compound selected from the isomers of
dichloropentafluoropropane comprises at least a maior
proportion, e.g. at least 50 % by wei~ht! of the
1,1-dichloro-2,2~3,3,3-pentafluoropropane isomer. More
1~ preferabl~v, the at least one isomer of
dichloropentafluoropropane contained in the fire
extinguishin~ composition is entirel~
1,1-dichloro-2,2,3,3,3-pentafluoropropane.
In addition to the at least one isomer of
dichloropentafluoropropane, the fire extinguishin~
compositions of the invention ma~ further comprise one
or more other fire extinguishing compounds, such as a
completel~ halo~enated fluorobromoalkane or
fluorobromochloroalkane. Examples of such compounds
include, inter alia, dibromodifluoromethane,
bromotrifluoromethane, and bromochlorodifluoromethane.
Other suitable fire extinguishing compounds which ma~
be included in the fire extinguishing compositions of
the invention include those disclosed in the present
applicants European patent application EP-383 443 A2,
e.g. l-bromo-1,2,2,2-tetrafluoroethane.
The fire extin~uishing compositions of the
invention may optionally comprise one or more
coad~iuvant agents havin~ a boiling point below 0CC
.
:

-- 3
(hereinafter referred to as coadiuvants), which may
enhance the effectiveness of the fire extin~uishing
compositions, e.g on delivery from a fire extinguishin~
device. Preferred coadjuvants are the haloalkanes,
especially the haloethanes and halomethanes, having a
boilin~ point below 0C, preferred examples of which
are chlorodifluoromethane, 1,1 2,2-tetrafluoroethane
and 1,1,1,2-tetrafluoroethane. Other suitable
coadiuvants include the heptafluoropropanes, e.g.
1,1~1,2,3,3,3-heptafluoropropane. The use of a
coad~iuvant is, however, not essential, since the fire
extin~uishin~ compositions of the invention may be
effectively delivered from a fire extin~uishin~ device
by the use of a standard gaseous propellant.
The fire extinguishing compositions of the
invention will normally comprise at least 50 % by
weight, preferably at least 70 % by weight and
especially at least 90 % by wei~ht of the at least one
fire extinguishing compound selected from the isomers
of dichloropentafluoropropane.
The fire extinguishing compositions of the
invention will normally be delivered from fire
extinguishin~ devices by means of a ~aseous propellant.
Suitable propellants are compounds of low toxicity and
high stability, preferred examples of which are
nitr-ogen and carbon dioxide. A particularly preferred
propellant for delivery of the fire extinguishing
compositions of the invention is carbon dioxide, since
this has been found to provide a particularly effective
delivery of the fire extinguishing compositions of the
invention. The fire extinRuishin~ composition is
typically pressurised in the fire extinguishing device
with 150 to 250 psi of the ~aseous propellant.

~ 4 - 2~2.~
The present in~ention is now illustrated, but not
limited, by the following examples.
Example 1
.
A Committee European Normalisation (CEN) llB fire was
started using 11 litres of n-heptane as the fuel. The
fire was extinguished in 4 seconds with 550 g of a fire
extinguishing composition comprising
1,1-dichloro-2,2,3,3,3-pentafluoropropane discharged in
; 8 seconds from a 760 ml Thorn extinguisher containin~
750 g of the composition pressurised to 200 psi with
carbon dioxide.
ExamPle 2
A Committee European Normalisation (CEN~ llB fire was
started using 11 litres of n-heptane as the fuel. The
fire was extinguished in 2.5 seconds with 400 g of a
fire extinguishing composition of
1,1-dichloro-2,2,3,3,3-pentafluoropropane discharged in
8 seconds from a 760 ml Thorn extinguisher containing
750 ~ of the composition pressurised to 160 psi with
carbon dioxide.