Fire is rapid combustion resulting in release of heat and light of flame which therefore makes fire prevention procedures very necessary. Fire occurs in different situations domestic, agricultural, forestry, industry and may result in loss of life and property.
Loss of life is due to poisonous gases and flames. Fire danger to life is given higher weight than fire hazard to property. More than 85% of fires are caused by electrical sparks or short circuits.
While most organizations aim to be insured against fires, the insurance is often not equal to the losses as some items are indeed irreplaceable thus it is more expedient that fires are minimized by adopting scientific engineering approach.
Aspects to be considered during design, construction and operation of organizations include safe escape of personnel, fire prevention, firefighting and minimization of loss of life and property, safety of personnel from fire, gases and smoke, reducing spread of smoke and gases, emergency operations and first aid measures.
Fundamentals and Elements of Fire
Fire is an active, rapid, burning (combustion) fast oxidation process accompanied by heat, light and poisonous gases/ smoke/carbon dioxide due to combustion. The flame is the luminous hot zone of fire.
Fire starts at a hot spot and spreads along combustible material to neighbouring areas in the presence of combustible material, air and heat. Various materials differ in their ignition temperatures and fire characteristics.
Combustion rate may be slow; there is slow evolution of heat but not by light, rapid ; rapid evolution of heat accompanied by light , spontaneous absorption of atmospheric oxygen at ordinary temperature.
Elements of Fire
Fuel: combustible material, most fuels have a flash point at which they give up vapours.
Heat or Ignition and temperature: Combining oxygen with fuel vapours releases heat energy which in turn vaporises more fuel
Oxygen (Air): Oxygen combines with flammable vapours at a flash point causing burning.
Initiation of fires requires heat and hot spot, air and flammable material.
Causes of Fires
Lapses in Safety management: negligence, carelessness, poor housekeeping, poor wiring, gas leaks
Human error: negligence: lack of awareness/ training
Accident beyond human control
General Fire Prevention
Fire is probably the most serious danger which any organisation will ever have to face. It can break out almost anywhere and can affect everyone. “Prevention is better than cure”.
Fire Prevention Regular fire prevention routines are one of the simplest and most efficient means of preventing fire. Fire prevention aims at not allowing the combination of the elements of fire.
Safety documentation for plant/ equipment and for civil/ storage/ installation/ commissioning/ operation/ maintenance phases of the project
Provision of fire-fighting systems (1) permanent (2) portable
Provisions for fire prevention at the civil design and works stage. Smoke and Carbon –monoxide alarms have been found to be very effective as means of early detection and control thus limiting fires and reducing loss of life and property.
Fire doors play an important role in the precautionary system; their purpose is to contain the fire, and to prevent the spread of smoke and toxic gases, which can be lethal even in small quantities.
Provisions in the electrical design and works- All Electrical work should be carried out by or supervised by certified personnel, avoid overloading electrical equipment, and earth all equipment
Organisation, awareness and training of personnel- The value of the nightly routine of switching off and unplugging electrical equipment (unless the equipment concerned is designed to run continuously cannot be overemphasized).
It is essential that the fire alarm system and a pre-arranged plan specific for the evacuation of each building should be tested regularly. Heads of Units must ensure that fire drills are held based upon agreed on intervals following a risk assessment.
Where appropriate some staff can undertake the extra duties of Fire Marshals/Officers. These must be specially trained and given specific duties in terms fire hazards or during a fire.
Information concerning fire safety should be widely dispersed and staff trained where necessary. Ensure signage relating to fire safety such as the Fire Routine procedure, Fire exits, and Fire assembly points are conspicuously placed.
Precautions against fires, Housekeeping and Monitoring- Proper storage and handling of Flammable and explosive materials- liquids or gases, avoid use of inflammable material, develop check list and monitor regularly, Ensure all fire-fighting equipment are checked, refilled and/ or serviced when due.
More people die through inhaling smoke than through burns. Fire doors must therefore not be propped or wedged open; to prop open a fire door can cost lives if a fire breaks out. The Safety/Fire Officer should routinely assess for fire risks during monitoring.
First Aid Facilities
Insurance coverage during construction and operation
Fire extinguishing techniques
Starvation: Removal of fuel
Smothering: Reducing the amount of oxygen available by dilution or by introducing other inert media.
Blanketing: Cutting off of fuel vapours mixing with oxygen by applying an external media such as the use of foam. It is valuable in extinction of fires of oils and other flammable liquids.
Cooling: Reduces the temperature to one at which combustion cannot continue.
Breaking of branched chain reaction: Dry chemical powder containing halogenated hydrocarbon reacts with the hydrocarbon molecule on fire.
Fire hydrants: Water systems. May be internal or external. Pump should be independent of other equipment within the premises.
Portable Fire extinguishers – New extinguishers are 90% red and are distinguished by a colour panel
Red: Water. The extinguisher is of limited use can only be used for class A fires of wood, paper or organic material; works by cooling.
Green Panel: Foam. Cools and smothers fire. Suitable for Class B fire of fuel or liquid and class A fires. Do not use for electrical fires.
Black Panel: Carbon dioxide. Smothers fire. Good general purpose extinguisher. Good for class B fires
Blue Panel: Dry Powder. Smothers fire and is a good general purpose fire extinguisher. Useful for class A, class B and class C (flammable gasses).
Buckets: filled with sand
Water spray systems may be high velocity or medium velocity
Sprinkler systems: used mainly in stores or usually unoccupied buildings
Fire Routine Procedure
Each Head of Unit must ensure that all members of staff are instructed in the action to be taken should a fire break out. This is most conveniently done by giving each member of staff written instructions in the form of a Fire Routine Procedure probably in the induction hand book.
This Fire Routine procedure should also be placed at very visible sites where even visitor can easily site them. Visitors should be encouraged to view the notices. Staff should be encouraged to commit to memory the standard instructions in the Fire Routine Procedure; there will be no time to read these instructions in an emergency.
On Discovering a Fire
If a fire is discovered’ the discoverer should:
Raise the alarm: Operate the nearest fire alarm. If no fire alarm is provided, shout “Fire”.
Act Swiftly: Leave the building. Ensure that the nearest fire service is informed of the fire. Do not panic
Do not take risks
Electric power supply and other fuel supplies switched off
Use of portable fire extinguisher, water or sand for small fires if trained/ able/ allowed
Activate automatic fire fighting system
On Hearing the FireAlarm
On hearing the fire alarm, all staff must leave the building immediately by the nearest available exit, closing doors. Lifts must not be used.
It is essential that the means of escape from a building should function efficiently. Exit doors should be fastened so that they can be easily and immediately opened from the inside without the use of keys. Exit routes must not be obstructed or used as storage areas.
In addition, all fire/smoke doors should be closed when buildings are empty.
All personnel are well advised to become familiar with as many as possible of the exit and escape routes from the building in which they normally work.
All Staff should assemble at the Fire Assembly point and a head count taken.
|Combustion Material involved
|Fire extinguishing medium
|Fires involving ordinary solid materials such as wood, coal, plastics, cloth, paper, rags, rubbish, construction and packaging material
|Water or solution with high water content. Cooling and wetting of material quenches fire
|Fires involving Flammable liquids/ vapours /solvents: Transformer oil, diesel oil, solvents, liquid, chemicals, lubricating oils, paints/varnishes/thinners, greases, contained, uncontained
|Limiting air or oxygen supply, inhibiting fire, Dry chemicals, foam, Halon. Water is unsuitable
|Fires involving live electrical equipment in energized state. If equipment is dead becomes class A or B
|CO2 gas , dry chemicals, water is unsuitable
|Fires involving metals like magnesium, titanium
|Normal extinguishing media unsuitable. Special chemicals and techniques used
|Fires involving Flammable gases and fuels, hydrogen, ammonia, acetylene, LPG, petrol, Furnace oil
|Starvation of fire is most useful. special methods, close inlet valve
Four types of fire extinguishers should be provided within the premises. The extinguishing media used are: water, carbon dioxide, foam and dry powder.
The external appearance of each type of extinguisher is different and each carries its own instructions for use. In some buildings, hose reels are also provided.
Fire blankets should be provided in many locations and should be used for smothering fires involving flammable liquids or burning clothing.
All personnel should know the location of the firefighting equipment in their area of work, to know on what type of fire each piece of equipment can be used and how each should be used. This is achieved by training.
Whenever firefighting equipment has been used, an immediate report must be made to the Safety Officer or to the Fire Safety Unit (If there is one) so that the equipment may be recharged or replaced.
In all buildings, particularly residences, protection of human life must take priority over fighting fires. The person discovering a fire must promptly initiate the emergency procedures listed above. Delay can be fatal as, once a fire is out of control, it can spread rapidly and cut off escape routes.
If allowed by the organisation, especially when trained, and without endangering personal safety, attempts can be made to contain and control a fire until the Fire Service arrives.
It must be ensured that the correct type of fire extinguisher is used. The wrong choice can turn a minor incident into a major event.
The Fire extinguisher is used according to manufacturer’s instruction. It must be remembered to take a position between the fire and the exit so that the escape route cannot be cut off., ensure awareness of what is happening in the surrounding area and take account of limitations.
The greatest hazards to fire fighters are the effects of asphyxiant, irritant and toxic gases, smoke and fumes generated from the combustion of plastics and other materials. Never attempt to fight a fire wearing a respirator or breathing apparatus. Never fight a Fire without anyone else’s knowledge.
After a Fire
Even if a fire appears to have been successfully extinguished by staff, it will still be necessary to ask the Fire Service to check that the fire has not unknowingly spread, and that materials or the building fabric cannot reignite.
Unit heads must ensure that all fires within the building are recorded and reported to the Health and Safety officer or Manager
In conclusion, while fire prevention is everyone’s responsibility, Fire-fighting should best be taken on by trained personnel.
It would be in the best interest with a high risk for fires as a result of their production processes to ensure fire training of every member of staff if feasible.
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Otherwise it is important for all staff members to be conversant with the Fire routine procedures and participate in fire drills.
Fire is probably the most serious danger which any organization will ever have to face. It can break out almost anywhere and can affect everyone. “Prevention is better than cure”.
Fire Control is achieved using Fire alarms, Smoke and Carbon –monoxide alarms, Fire extinguishers, Fire Doors, Fire Drills and Fire marshals. Ensure every employee is knowledgeable of the Fire Routine Procedure.
On discovery of a fire the discoverer should raise the alarm, act swiftly, do not take risks and do not panic Fire-fighting should best be taken on by trained personnel.