Water Fire Extinguisher

You see it all the time in auto racing, a car catches on fire and then when the fire personnel arrive they douse it with huge amounts of foam. What is this stuff that seems to be the flame retardant of choice when it comes to fuel fires? Foam extinguishers use a substance which forms a foamy blanket over the fire’s fuel which seals it. The various classes of foam extinguishers can be put into three groups: Class A foams for general use, class B foams for wilderness and variable fire suppression and industrial fire control foams.

Industrial fire control foams have to be robust and specially formulated for the rigors of industry. The steel industry for instance uses Arctic fire, a liquid agent that cools super heated materials more quickly than water or ordinary foam. FireAde is a classic foaming agent used in industry that emulsifies burning liquids and renders them non-flammable.

In cases of firefighting in the wilderness a Compressed air Foam System is used to extend the water supply. This system is used in a wide variety of situations and most fire departments have a truck dedicated to that purpose. It is a standard water pumping system with an entry point for compressed air to be added to a solution that generates foam. The air compressor used for this also propels the compressed air foam farther than a standard hose nozzle. It has the capability to produce a wide range of foam types and qualities for the most appropriate response to any situation.

The most common type in portable foam extinguishers is Aqueous Film Forming Foam which can be used on general material fires. This type of foam is water based and has the ability to spread over the surface of hydrocarbon based liquids. Fuel related fires are the primary reason for foam extinguishers as they prevent the fire from breathing.

Alcohol-Resistant Aqueous Film Forming Foams form a resistant film over an alcohol related fire to prevent the alcohol from breaking down the foam. It also forms a barrier between the fuel and instigators of fire and addresses any flammable vapor which may be produced.

Film Forming Fluoroprotein is a mixture of synthetic agents and natural animal proteins which is more environmentally friendly than other general types of foams. This type of foam is available in many forms to include regular, film forming, alcohol resistant and alcohol resistant film forming. It creates an impenetrable foam blanket over alcohol based liquids and is used widely in motorsports.

Though used primarily for fuel and alcohol related fires foam is also used for ordinary solid combustibles. Foam is a solid choice for an extinguishing substance due to its superior ability to control fires quickly and the different variations it comes in.