Water and Foam
Water extinguishers work by quickly removing the heat from the fire. Water extinguishers are only suitable for fighting Class A fires that involve materials such as wood, paper and textiles. Water should not be used to fight Class B fires because flammable liquids could be spread by the steam from the water, neither should they be used for Class E electrical fires because water conducts electricity there is a risk of electrocution.
Foam extinguishers work by quickly removing heat and oxygen from the fire. Foam extinguishers are suitable for Class A and Class B fires. They are especially suited for controlling Class B flammable liquid fires because the foam has a blanketing effect that smothers the flames without spreading the fire.
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