Water is considered the oldest extinguishing agent of mankind. Nowadays, its effectiveness is considerably increased and preserved by means of extinguishing additives, thus making it durable at the same time.
The main extinguishing effect of water is based on cooling. The high heat of evaporation extracts energy from the burning material. In addition, the water vapour displaces the oxygen needed for combustion. The fire of fire class A is smothered (secondary extinguishing effect).
Water can only be used for class A fires. This class includes all fires of solid substances, mainly of an organic nature, which normally burn with the formation of embers, e.g. wood, coal, paper, straw.