Fire Protection
Portable Fire Extinguishers (PFE)
Portable Fire extinguishers (PFE) are small hand held appliances that are used to put out fires in the very early stage of their inception. There are different types of extinguishers in use and their classification is based on the types of fires on which they are effective. Hence an understanding of the types of fire is very essential in selecting the appropriate type of extinguisher for use in a particular location.
Selection of PFE
Selection of portable fire extinguishers should be done based on the nature of fire load - type of materials present in the premise.
Class of Fire
Class A - Fires involving materials such as wood, paper, fibers and the like which are in a solid form= Water type
Class B - Fires involving materials such as kerosene, petrol, paints,
grease, solvents and the like which are in a liquid form =Foam or Carbon Dioxide (CO2) or Dry Chemical Powder (DCP) type
Class C -Fires of an electrical nature involving electric equipment
resulting from combustion of circuit breakers, wires, and other
electric devices and equipment=Carbon Dioxide (CO2),
Dry Chemical Powder (DCP) type
Class D - Fires involving materials such as magnesium, aluminum
and the like which are reactive chemicals or active metals=Special
type of Dry Chemical Powder type
Class K - Fires involving cooking media like vegetable oils, animal oils
and fats and those which generally occur in Kitchen= Wet chemical
fire extinguishers
Quantity
At least two extinguishers are to be provided in every area/ room. The appliances are to be so distributed over the entire floor such that a person has to travel not more than 15 metres to reach the nearest appliance. As per TAC (Tariff Advisory Committee) Guidelines - For any property, basic protection shall be appliances suitable for class A fires, since class A fires are of universal character.
One 9 litre water / sand bucket is to be provided for every 100 square meter of floor area and one 9 litre water type extinguisher is to be provided for every six buckets or part thereof with a minimum of one extinguisher and two buckets per compartment of the building.
Where class B fires are anticipated, a suitable number of appliances as determined above shall be replaced with appliances suitable for B class fires.
As a thumb rule the requirements specified above would mean approximately 2 extinguishers for every 600 m2 of floor area or part thereof which would however be slightly less in case of light hazard occupancies having larger than 600 m2 floor area in a single fire compartment.
Note.
- In rooms containing only electrical equipment such as electrical transformers, switch gears, motors or other electrical apparatus, not less than 2 KG Dry Powder or carbon Dioxide type extinguishers are to be provided within 15 metres of the apparatus.
- In rooms containing motors and/or other electric equipment along with other machineries or facilities one 5 Kg. DCP or Carbon Dioxide extinguisher is to be installed within 15 metres of the equipment in addition to the requirements that were earlier specified.
Location
Generally Portable Fire Extinguishers (PFE) are to be placed as near as possible to exits or staircase landings by also taking into consideration (wherever possible) the normal routes of escape of persons. Placing PFE in such positions will enable these to be seen by persons following the natural impulse to get out of danger.
Standards further prescribe that PFE's be so located that the top of the extinguisher is located at a height of 1.5 metres from the finished floor level or that the bottom of the extinguisher is located at a height of 1 metre from the finished floor level.
Maintenance
Once a month the extinguishers should be checked to ensure that all moveable parts are working properly, that the plunger is in fully extended position, that the nozzle is not obstructed in any way and that there is no leakage of the extinguishing medium from the glands and nozzles. The extinguishers should be cleaned superficially and the brass parts should be polished. The nozzle outlet and the vent holes in the threaded portion of the cap should be checked for clogging.
Once a month, carbon dioxide extinguishers should be weighed. If the weight recorded is less than 90% of the weight of the fully charged extinguisher as marked on the extinguishers body it should be sent for recharging.
Hydraulic tests of the extinguishers should be carried out and records maintained. The recommended schedule for refilling/ performance test and hydraulic test of extinguishers as per IS: 2190-1992 'Code of practice for selection, installation and maintenance of first-aid fire extinguishers' is as given below:
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Type of Extinguisher
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Refilling/Performance Test
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Hydraulic Pressure Test
|
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Water Type (stored pressure)
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Once in 2 Years
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Once in 2 Years
|
|
Foam Type
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Once in 2 Years
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Once in 2 Years
|
|
DCP Type
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Once in 5 Years
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Once in 3 Years
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CO2 Type
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Once in 5 Years
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At every recharging, but at least once in 5 years.
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A system should be established for upkeep and maintenance of Portable Fire Extinguishers. When this activity is outsourced it needs to be ensured that the external agency carries out the maintenance as per the recommended schedule and an officer or employee of the company is made responsible for this activity.
Sources for additional information:
- IS: 2190 - Code of practice for selection, installation and maintenance of first-aid fire extinguishers
- TAC's Fire Protection Manual.
- NFPA 10 - Standard for Portable Fire Extinguishers
