Portable fire extinguishers are called as first-aid fire fighting appliances as they are effective only at the incipient stage of fire. The purpose of the portable fire extinguisher is to enable an individual with minimum training and orientation to extinguish an incipient fire. The portable extinguisher is of great value in controlling and extinguishing a fire in the incipient stage of fire provided the right type of extinguishers are readily available nearby and used successfully.
Healthy portable fire extinguish is a vital tool to protect life and property. A fire extinguisher must be considered as a part of the total fire protection system, consisting of fire protection measures, a person, an extinguisher, and a procedure for initiating an alarm. The provision of fire extinguishers is must irrespective of fix fire protection and fire fighting systems installed at premises.
Employees who are not regular firefighter are likely to make errors in the operation of fire extinguishers due to a lack of confidence and panic. The wrong operation of fire extinguishers has resulted in serious injuries. The effectiveness/results of fire extinguishers vary from person to person as it depends on the knowledge, skill, training, confidence, and courage of a person operating a fire extinguisher. Apart from the usefulness of fire extinguishers, several limitations are inherent in the design and the functional concept of portable fire extinguishers. These are Fire Extinguisher And Type of Extinguisher
A] Limited amount of, extinguishing agent
B] The need for special recharging facilities
C] The limited range of the discharge agent
D] The limited discharge time of the extinguisher
E] Extinguishers designed for specific situations.
Classification of fire ;
Portable fire extinguishers are not of great help and value to save life and property from fire but all portable fire extinguishers are not equally effective on all types of fire. it entirely depends on the type of material involved in fire. based on the material involved in a fire, fires are classified into five classes-Fire Extinguisher And Type of Extinguisher
Classification Fo Fire & Suitability Of portable Fire Extinguisher ;
Suitable portable fire extinguishing agent
CLASS – A
The selection, installation, and maintenance of portable first-aid fire fighting appliances shall be carried out in accordance with guidelines contained in IS:2190-1979. Provision for spare refills for extinguishers shall be made at 10 percent of total extinguishers. the refills shall conform to IS:5490 (part 1&2)
The Limitations of various Types of extinguishers ;
 Water-type ;
- Surface tension – Slows penetration
- reactivity – with reactive chemicals & metals
- Conductivity – in case of electric fires
- Freezing Temp – Unsuitable for very low temp. areas
- Viscosity – Low so runs off quickly -can’t foam blanket
- Heaviness – Sink in low F.P. liquids tanker can boiling
 CO2 Type ;
- Smoldering embers and not metal surfaces may reignite after the smothering atmosphere disappears by dissipation.
- Takes a long time to keep the O2 level below 6%
- Not effective for oxygen-containing material such as cellulose nitrate.
- Reactive metals and hydrides decompose co2- so unsuitable.
 D.C.P Type ;
- Cannot penetrate deep
- After smothering the fire, water is needed for A types fires.
- cannot produce lasting inert atmosphere above the surface of flammable liquids-so no permanent extinguishment.
- Unsuitable for sophisticated electrical/electronic equipment
 Foam Type ;
- Not suitable for liquefied compressed gases such as butane, butadiene, etc.
- High viscosity oils burning for a long period may cause violent frothing and forceful expulsion of burning contents.
- Unfit for electrical equipment
- unfit for reactive chemicals & metals