Which of the following statements about fire fighting foams is MOST accurate?
A) The majority of fire fighting foams are Class A and Class K.
B) Class A foam is especially effective on hydrocarbon fuels and polar solvents.
C) Foam works by forming a blanket of foam on the surface of burning liquid and solid fuels.
D) Foam works by increasing the surface tension of water, making fire streams more cohesive to reach a greater distance.

Question

Quizplus · Accepted Answer

Foam works by forming a blanket on the surface of burning fuels, isolating the fuel from the air (oxygen) and cooling the fuel. This mechanism is different from increasing water's surface tension, which is not the primary function of firefighting foam. Class A foam is designed for fires involving ordinary combustibles, not specifically for hydrocarbon fuels or polar solvents, which are more in the domain of Class B foams. Class K foams are for kitchen fires involving cooking oils and fats.

Which of the Following Statements About Fire Fighting Foams Is