Foam (Class B)

A Class B foam is a fire-fighting foam designed for use on Class B fires, which involve flammable liquids, such as gasoline, oil and propane. Class B foam is made up of water, foam concentrate, and air, and is formulated to spread rapidly over the surface of the fuel, form a vapor-sealing blanket, and extinguish the fire by separating the fuel from the air.

Class B foam works by creating a thick layer of foam on the surface of the fuel, which reduces the fuel's vapor pressure and prevents the release of flammable vapors. This enables the foam to cool the fuel and extinguish the fire. Additionally, Class B foam can be used to suppress flammable vapors, making it an effective tool in reducing the risk of flashover and explosion.

Class B foam is commonly used in industrial facilities, airports, and marine settings, where the risk of large flammable liquid and gas fires is high. It can be applied using handlines, foam systems, and water-dropping helicopters. It is important to select the appropriate type of Class B foam concentrate based on the specific type of flammable liquid or gas involved in the fire to ensure that the foam is effective and does not create any additional hazards.