Why do fire fighters use foam?

Answer 1

There are several methods firefighters use to put out fires. Fire needs 3 things to survive, called "the triangle of fire", heat, oxygen, and fuel. All firefighting techniques remove one of those elements to put out the fire. The first is to spray water or fire retardant on the fire, either using a fire hose or a special aircraft. They smother the fire, removing oxygen, and water cools it. Another method is a fire break. A fire break is a space with no fuel. Therefore, the fire cannot burn past the fire break, and the fire eventually exhausts its fuel and burns out. Those are the two most common ways to put out a fire.

Recent thinking on fires treat them as a four legged stool, now including "chain reaction." Some newer firefighting methods simply break the chain reaction to stop the fire. Chemicals are often used on fires, but the best know way is to use a fine spray of water. Although the water cools the fire (and resulting steam remove oxygen), a spray or even foam can separate the fuel from the air, starving the fire as it rapidly cools.

Answer 2

Hello, There are different types of fire fighting foam available to used for various types of fires, Most commonly a Class A Foam will be used for structure fires as foam reduces the amount of water damage caused by extinguishing the fire. Since water puts out fire by cooling the object that is burning to reduce the amount of combustible gasses produced, foam lessens the water from turning to steam and it flows less then just water alone. Some foams you can spray on a wall or furniture and it will stay, thus preventing the fire from spreading to that object.

Most commonly foam is used in liquid fuel fires and hazardous materials spills to prevent the spilled liquid from turning to a vapor and catching fire. Take a gasoline fire for example we use a Aqueous Film Forming Foam. That particular type of foam is sprayed on the ground in front of the flammable liquid, and is then rolled (pushed) over the surface of the liquid to cover the entire surface of the spill. As the foam covers the gasoline it breaks the chemical reaction of the flammable liquid fire, also as the foam breaks down it forms a film that floats on the surface of the fuel so that the fuel can cool below its ignition point, so that the spill can be mitigated (stopped from getting worse) and remediated (cleaned up). However diffrent types of materials spilt or burning will dictate the type of foam used.

Answer 3

Foam is used to smother the fire usually in cases where water would just move the fire around and make amtters worse such as an oil or gasoline fire. Foam deprives the burning liquid of oxygen and suffosates the fire. If you sprayed water on a gasoline fire for example, the fire would still burn and the water would push it to other areas.

Answer 4

They use water because water is a natural element that can distinguish fires naturally with out chemical interference

Answer 5

because they only usually only put it out with water because some fires will be made bigger if you put water over it !!