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Learn More in these related Britannica articles: Numerous agents besides water are used; the selection of the most appropriate one depends primarily on the nature of the materials that are burning. Water performs two of these functions: A primitive hand pump for directing water at a fire was invented by Ctesibius of Alexandria about bce, and similar devices were employed during the Middle Ages.

Water is suitable for putting out fires of only one of these classes Athough these are the most common. George Manby introduced a handheld fire extinguisher—a three-gallon tank containing a pressurized solution of potassium carbonate—in Small fires are classified according to the nature of the burning material.

The water may contain a wetting agent to make it more effective against fires in upholstery, an additive to produce a stable foam that acts as a barrier against oxygen, or an antifreeze.

Fire extinguisher

Hoppfer used explosive charges to disperse fire-suppressing solutions. Class D fires ordinarily are combated with dry chemicals. Many simple fire extinguishers, therefore, are small tanks equipped with hand pumps or sources of compressed gas to propel water through a nozzle.

Secondary considerations include cost, stability, toxicity, ease of cleanup, and the presence of electrical hazard. Fires of classes A, B, and C can be controlled by carbon dioxide, halogenated hydrocarbons such as halon s, or dry chemicals such as sodium bicarbonate or ammonium dihydrogen phosphate.