Fire is a rapid chemical reaction between oxygen and a combustible material that results in heat, light, flames, and smoke. For a fire to exist, it requires oxygen, heat, and a fuel source. There are different classes of fires based on the type of fuel: Class A for ordinary combustibles, Class B for liquids, Class C for electrical fires, and Class D for metal fires. Fires can be extinguished by removing one of the elements of the fire triangle - oxygen through smothering, heat through cooling, or fuel through starvation. Common fire extinguishers use water, foam, dry chemical powder, carbon dioxide, or the now banned halon to fight different classes of fires.

1. 1
What is Fire?
Fire Triangle
Heat
Fire is a very rapid chemical reaction between
oxygen and a combustible material, which results
in the release of heat, light, flames and smoke.
For fire to exist and sustain following four
elements must be present at the same time:
 Enough oxygen to sustain combustion,
 Enough heat to raise the material to its
ignition temperature,
 Some sort of fuel or combustible material.

2. 2
Types of Fires
Fires are classified by the type of Fuel involved.
 Class A Fire Ordinary solid combustibles (usually
from an organic origin)
 Class B Fire Liquid combustibles/flammables
 Class C Fire Electrical fires
 Class D Fire Metal fires

3. 3
Types of Fires (Contd….)
 Class A Fire Wood, Paper, Plastic, Rags…
 Class B Fire Gasoline, Oil, Grease, Paint…
 Class C Fire Electronic equipment, Motors, Switchgear…
 Class D Fire Sodium, Potassium, Magnesium…

4. 4
Methods of Extinguishing Fire
1- Starvation – Removing Fuel
2- Smothering – Removing Oxygen
3- Cooling – Removing Heat
Heat

5. 5
 Need 3 elements to
sustain a fire
• Oxygen
• Heat
• Fuel
 Removal of any one
element will extinguish
the fire
Starvation

6. 6
 Need 3 elements to
sustain a fire
• Oxygen
• Heat
• Fuel
 Removal of any one
element will extinguish
the fire
Cooling / Quenching

7. 7
 Need 3 elements to
sustain a fire
• Oxygen
• Heat
• Fuel
 Removal of any one
element will extinguish
the fire
Smothering

8. 8
Types of Extinguishers
1- Water
2- Foam
3- Powder
4- Carbon Dioxide
5- Halon BANNED!

9. 9
Fire Extinguisher Suitability
Fire Extinguisher Fire Type
Water
Foam
Carbon Dioxide
Dry Chemical Powder /
Halon

10. 10
Rules for Fighting Fires
 Fight fire in downwind direction.
 Start fighting the fire from safe distance (2-5 m).
 Do not leave the fire area unless you are sure that the fire is
completely out.