Fire retardant

Substance reducing flammability Fire retardant dispersed aerially onto brush adjoining a firebreak to contain the Tumbleweed Fire in California, in July 2021 A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants may also cool the fuel through physical action or endothermic chemical reactions. Fire retardants are available as powder, to be mixed with water, as fire-fighting foams and fire-retardant gels. Fire retardants are commonly used in fire fighting, where they may be applied aerially or from the ground. Principles of operation In general, fire retardants reduce the flammability of materials by either blocking the fire physically or by initiating a chemical reaction that stops the fire. Physical action There are several ways in which the combustion process can be retarded by physical action: By cooling: Some chemical reactions actually cool the material down. By forming a protective layer that prevents the underlying material from igniting. By dilution: Some retardants release water and/or ca