08/08/2026
🚒 Water is an interesting, efficient, and natural Firefighting agent.
Used for Class A Fires.
Characteristics of Water:
Transparent.
Colourless.
Odourless
Tasteless.
Cannot be compressed.
Boiling water can extinguish fire more quickly.
When water boils at 100°C, it turns into steam at a ratio of 1:1700. So, for every unit of water that is boiled, 1700 units of steam will be produced.
Any given quantity of water always occupies its own specific volume.
Formula: H2O
At higher altitudes, the temperature of the boiling point is lower.
Cold water boils faster than hot water.
Fresh water boils faster than Saltwater.
Ocean water freezes at a lower temperature than freshwater 28.4oF.
Water starts to expand between 4°C and 0°C.
Water is less dense as a solid than as a liquid.
A litre of water weighs 1 kilogram.
Pure water has a neutral PH of 7, which is neither acidic (less than 7) nor basic (greater than 7).
Latent Heat Vaporization 22.6x105 = 2,260 kJ/kg.
Excellent solvent.
Water has a natural ability to be attracted to itself and so it collects in beads. This causes it to form drops rather than to spread out over a surface.
Very high surface tension.
High specific gravity.
Low density as a solid.
Density: 997 kg/m3
Boiling point: 212'F (100C)
Molar mass: 18.01528 g/mol.
Melting point: 32'F (O'C).
Water cools and smothers fire simultaneously.
Cooling Effect: The small droplets created by water mist systems increase surface area to maximize the efficient absorption of heat.
Oxygen Displacement: The small droplets evaporate rapidly and expand to displace oxygen in the proximity of the fire.
Radiant Heat Attenuation: The small droplets provide effective protection from radiant heat.
High polarity.
Water can generate static electricity.
Water should never be used to extinguish electrical fires or fires involving flammable liquids.
Pete Learmonth 🚒
