FIRE PREVENTION & FIRE FIGHTING

                                                                     FIRE

·        Fuel +oxygen + heat = fire

·        Fire is exothermic reaction

·        Fire is a process of burning

DEFINITION: - “fire is a chemical reaction initiated by presence of heat energy in which a substance combines with oxygen of the air, the process accomplishes by emission of energy in the form of heat, light and sound.”

# Essentials of fire:

1.      Fuel

2.      Oxygen

3.      Heat source

4.      Process of chain reaction

# Terms related to fire:

1.     FLASH POINT: It is the lowest temperature at which the fuel gives off enough vapors that ignite for a moment when a small flame is brought near to it.

2.     FIRE POINT: It is the lowest temperature at which the vapors of the fuel burn continuously for at least 5 seconds when a tiny flame is brought near to it. In most cases the fire points are 5⁰ C to 40⁰ C higher than the flash points.

3.      FLASH OVER POINT: The point at which the fire changes from two dimensional to three dimensional manifestations. Structural damage begins after the growth of the fire to flash over point.

4.     IGNITION TEMPERATURE: The minimum temperature to which a material must be heated in order to initiate or cause self sustained combustion independent of heating element.

5.     LOWER EXPLOSION OR FLAMMABILITY LIMIT: Minimum concentration of vapor in oxygen below which the propagation of flame will not occur in the presence of an ignition source.

# TYPES OF COMBUSTION:

1.     Rapid- gas is ignited, produces heat and light.

2.     Spontaneous- without the application of any external heat

3.     Explosion- Combustion in confined place under pressure, heat and light is produced (usually with sound)

 

 

 

# CLASSES OF FIRE:

A class - wood, paper, textile, rubbish grass etc.

B class – oils, petroleum products, varnishes, paints, solvent greases.

C class – fires of electrical origin

D class – Burning metal viz. aluminium zinc, magnesium, potassium.

E class – gaseous substances.

 

# METHODS OF EXTINGUISHING A FIRE:

1.     Starving- Removing the fuel.

2.     Smothering- Removing the air. (Wrapping a fire blanket around the person, closing windows and doors, covering the frying pan with a lid)

3.     Cooling- Removing the heat. (turning off the source of heat, using fire extinguishers)

# PRECAUTIONS TO BE TAKEN FOR AVOIDING FIRE OR MINIMISING ITS EFFECTS(from the book photocopy.. page number 427)

# PROCEDURE IN THE EVENT OF FIRE:

1.      The fire brigade must be called immediately

2.      Do not panic

3.      Warn other people in the vicinity, raise the alarm

4.      Do not rush

5.      Follow the fire instructions

6.      Use appropriate extinguisher if small fire is there

7.      Close doors and windows, turn off gas and electricity if safe to do so.