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5.1.4.1. Fire Extinguishing agents

                                                                                      

The following are the common fire extinguishing agents

1. LIQUIDS
a) Water

Water will act ascooling agent that absorbs the heat and cools the burning materials .Water isthe commonly available extinguishing agents.

b)Foam

Foam is a mass ofbubbles that cover the fire like blanket and extinguishes the fire bysmothering. Mixing water and a foam-making agent (foam concentrate) producesbubbles

Chemical foam could be produced by mixing an alkali (usually sodiumbicarbonate) with an acid (usually aluminium sulfate) in water. When chemicalfoam was first introduced, these substances were stored in separate containers.These two chemicals are packed separately in a sealed, airtight container. Whenthese chemicals are intentionally mixed, they react and foam or froth ofbubbles filled with carbon dioxide gas are produced.

2.GASES

a)Carbon Dioxide (CO₂)

Carbon dioxideextinguishes fire by smothering. It dilutes the air surrounding the fire untilthe oxygen content is too low to support combustion. For this reason, it iseffective on Class B fires, where the main consideration is to keep theflammable vapours separated from oxygen in the air.

3. Solid (Dry chemical)

Sodium bicarbonate is commonly used dry chemical extinguishing agent. It is widely used because itis the most economical extinguishing agent. It is particularly effective onanimal fats and vegetable oils because it chemically changes these substancesinto nonflammable soaps.