Classification of fires and appropriate extinguishing agents

Fires are classified into six types depending on the material, which acts as fuel to start a fire as per International Organisation for Standardization –

In India ISO standards are followed –

1. Class A fires – Combustible materials: caused by flammable solids, such as wood, paper, and fabric
2. Class B fires – Flammable liquids: such as petrol, turpentine or paint
3. Class C fires – Flammable gases: like hydrogen, butane or methane
4. Class D fires – Combustible metals: chemicals such as magnesium, aluminum or potassium
5. Electrical fires – Electrical equipment: once the electrical item is removed, the fire changes class
6. Class F fires – Cooking oils: typically a chip-pan fire

As per  National Fire Protection Association (NFPA). This is followed in United States of America. They are :

1. Class A: Result from ordinary combustible materials, including wood, cloth, paper, and many plastics. 
2. Class B: Burn in flammable liquids, combustible liquids, petroleum greases, oils, alcohols, and flammable gases. 
3. Class C: Involve energized electrical equipment. 
4. Class D: Fires in combustible metals, such as magnesium, titanium, zirconium, sodium, lithium, and potassium. 
5. Class K: Fires in cooking appliances that involve combustible cooking media, such as vegetable or animal oils and fats.

What are the fire extinguisher colour codes?

The five fire extinguisher colours are:

1. Red – Water (Spray and Mist)
2. Cream – Foam
3. Blue – Dry Powder
4. Black – Carbon Dioxide (CO2)
5. Yellow – Wet Chemical