WATER FIRE EXTINGUISHER INFORMATION
Water fire extinguishers only work on Type A fires involving flammable solids. They are a good choice for some premises, such as storage facilities and warehouses. Water fire extinguishers are the original form of fire extinguisher and still one of the commonly used.
Water and Foam fire extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements.
Water extinguishers are for Class A fires only
---- they should NOT be used on Class B (flammable liquids) or Class C (electrical) fires.
The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.
What the A B C ratings mean on Fire Extinguishers
Fire extinguishers with a Class A rating are effective against fires involving paper, wood, textiles, and plastics. The primary chemical used to fight these fires is monoammonium phosphate, because of its ability to smother fires in these types of materials.
Fire extinguishers with a Class B rating are effective against flammable liquid fires. These can be fires where cooking liquids, oil, gasoline, kerosene, or paint have become ignited. Two commonly used chemicals are effective in fighting these types of fires. Monoammonium phosphate effectively smothers the fire, while sodium bicarbonate induces a chemical reaction which extinguishes the fire.
“C” ELECTRICAL EQUIPMENT
Fire extinguishers with a Class C rating are suitable for fires in “live” electrical equipment. Both monoammonium phosphate and sodium bicarbonate are commonly used to fight this type of fire because of their nonconductive properties.