All Fire-hazards are due to human-fault
Life can not
be thought of without fire. The fire with all its manifestations of flame, heat
and evolution of smoke and fumes is called as fire when it is not at its
desired places i.e the burners, ovens, furnaces or at flare-stacks. Actually
fire is chain oxidation process wherein free radicals from the surface of a
substance get energized to liberate in ionized state and react with oxygen in
its stoichiometric proportions with evolution of heat. When its temperature
reaches its ignition temperature, fire appears spontaneously. Once there is a
fire the radiant heat rapidly heat the
adjoining surface to release more fumes at its fire point which stokes the fire
which is called inhibition.
In an incidence of fire the flame
causes fire-spread, the heat causes heat radiation and the unburnt oxides and free radicals
constitute the smoke which rises up from the fire spot causing rapid air inflow
to the places of ignition which rapidly increases the rate of combustion and
flame dispersion. The smoke causes asphyxiation and toxic ailments to the
living beings The radiant heat causes burn injury to the living beings heats up
the ambiance causing new hazards like vapor-cloud explosions and radiation
hazards
Fire is a science and its
extinguishing methods are engineering subject based on the science of fire.
Hence it is important to know the fire chemistry before applying engineering
for its extinguishment. One should know the safety data of the substance involved.
Such data for thousands of chemicals are available in printed form which
contains the physical, chemical, toxicological and explosive characteristics
along with tips for safe storage house-keeping, packing, transport safety along
with medical treatment and fire fighting methods.
Fire extinguishment technology is
based on three important aspects of
fire. It is usually called the fire-triangle. These characters are (i) The
substance, (ii) Oxygen(air) and (iii) Source of heat. The other important
aspect is to contain the fire inhibition process. For example after we lit a
match stick if we hold the stick vertically up keeping the fire at the top the same will
extinguish after a while at its own , but if the stick will be hold opposite
the total stick will burn out.. The fire extinguishment method is based on
cutting off any one link of the fire triangle. Most fire extinguishers are
designed to cut off oxygen supply while the most ancient and widely used method
is to douse the fire with water. Means cut off the heat source..
The person in control of a premises in many cases does not posses adequate
knowledge on fire. He off-loads the job to a consultant .The consultant en cashes on the novice ness of the owner and installs the system suiting to his
terms. It is worth to cite some examples. One may visit any petroleum oil depot
which is installed by the public sector oil companies at the center or at a
corner of every important township by the side of the railway track in our
country. The oil tanks would be found installed side by side without leaving
safe distance among them. The fire hydrant points would have been installed at
a distance of 4 to 5 meters from the oil tanks. There may not be adequate fire
water storage and supply system. The fire water pump house would be inside the
depot which would be no better than a confined space. The design should take
account for the potential of the expected heat radiation in the possible worst
scenario. Actually in their worst scenario the radiation intensity inside the
licensed premises will be in the fatal range. In the Oil depot fire of IOCL in
Sitapura of Jaipur Rajasthan on 29th October 2009 the official had no option left but to abandon
the place and to let the oil burn off for weeks together. The explosion caused
a tremor of 2.3 in the ritcher scale within a distance of three kilometers
evacuation of half a million people within that area.12 persons were killed and
300 plus persons got injured due to the radiant heat Properties worth 400
crores rupees gutted according to the claims of the Sitapura Industries Association.
The funniest incident was along with the installation the fire water pumps were
also found melted beyond recognition. The officials who may not be strictly at
fault under section 120B (criminal conspiracy), sec.166 (Public servant
disobeying law with an intent to cause injury to any person, section 304A
(causing death a person due to negligence) and section 511(attempting to cause
a cognizable offense) were charged with those offenses.
The issue is a scientific subject. If
one adequately understand the subject why will there be any lacuna. The problem
there may be either;they have compromised with the fire safety requirements
or did not have an adequate and well rehearsed fire fighting arrangement.
The fire is classified into five classes. They are;
Class-A : Fire
due to combustible materials like wood textiles paper, rubbish and the likes.
Class-B : Fire
from flammable oils, petroleum products ,solvents greases, paints etc.
Class-C : Fire
from gaseous substances(hydrogen LPG,LNG, Methane etc.
Class-D : Fire
involving chemicals and active metals
Class-E : Fire
involving electrical short circuit electrical equipments and delicate machines
The recommended fire fighting
materials for such type of fires are;
Class-A: Water, dry sand and
soda-acid
Class-B: Carbon dioxide Dry
chemical powder and water cooling
Class-C: Carbon dioxide , Dry
chemical powder and dry sand
Class-D: Chloride based DCP dry
sand and water if compatible
Class-E: Carbon dioxide, DCP, dry
sand
It is said that the biggest fire incidences
the world has yet noticed could have been doused with a cup of water had it
been fought at the time of incidence of the fire. Therefore the fire safety
requirements shall have a fool proof extinguishment strategy. Accordingly there
shall be adequate facilities to prevent and to fight a fire. Broadly they are;
Fixed systems-
Fire hydrant system having the user points at strategic locations, along with
Fire water pumping
devices, fire water pond well designed piping network
Water hoses, nozzles,
monitors and other water spraying devices.
- Foam pouring arrangements and chemical
storage installations
- Closed loop water cooling arrangements
- Smoke or heat
detection system
Mobile
system-Fire tenders, truck laden fire engines, fire extinguishers, foam
tenders.
Such systems
need periodic testing and technological auditing by experts and timely
updating.
The working system should be for isolation of
the affected region and prevention of fire spread
Isolation process: Fire always burn laminar and the flame travels upward.. Hence when the
top surface is burning the materials can
be retrieved from the bottom. In thatched house fire the burning house is
segregated by pulling out the combustible roofing materials from the connecting
roof.
Fire spread:
Fire is pacified by gently pouring the fire hydrant chemicals on the fire
surface from the spreading side so as to
cut off oxygen supply from the source
Fire fighting system should be kept on auto: The
hydrant system is advisable to be kept on auto
in addition to manual operating options.
Foam pouring system: All oil storage tanks need be provided with inbuilt foam pouring
arrangement
Water cooling arrangements: All storage installations shall have individual closed loop water cooling
device.
Fire fighting team: The fire fighting team should consist of experienced fire professional.
No person in such team shall have any physical or clinical disability. Persons
with eye defect heart ailment blood pressure and epilepsy should not be allowed
in a fire fighting team. Fire proximity suits, face shields, safety shoes, and
self breathing appliances shall be adequately available to the fire-men. From
among the team there shall be a fire rescue team equipped with flexible safety
ladders and motorized high rise rescue devices.. And a planned communication
system.
First aid team:
This team shall consist of medically trained persons equipped with all type of
first-aid equipments.
Fire drill:
Fire drill is advisable to be conducted frequently. As far as practicable such
drills should be presented for assessment by some outside experts. A register
need be maintained wherein the assessors be requested to note their advices and
feelings. Such register shall be discussed after every drill and then reviewed
by the owner of the premises and the remedial measures be taken without any
compromise.
Beside these arrangements all
buildings or confined places should be provided with clear approach road, exit
routes. All premises need frequent fire audit and its compliance.
The author has more than 32 years of
experience in this field. He thinks if there is no compromise on any fire
safety requirements the fire will always be in control of your finger tips. In
the recent Maharastra secretariat building fire on 22nd June 2012
wherein 5 civilians lost their lives the visible short falls are unplanned
vehicle parking chocking the approach route which caused delay in approaching
the fire in rage, improper house keeping causing problems in isolating the
fire, inadequate fire fighting infrastructure, absence of a well rehearsed fire
fighting team and lack of knowledge of the inmates on the effects of fire are
the few..
As usual the investigating team would submit
a stereo type report. Some head may roll. But we should realize that all
accidents never happen, they are caused. Similarly all fires are caused. The
owner can not say he is without any fault.
