What type of agent is AFFF primarily categorized as?

Aqueous Film-Forming Foam (AFFF) is primarily categorized as a foam agent. This classification is due to its formulation, which includes both water and specific surfactants that create a stable foam when mixed. AFFF acts by forming a film that spreads over the surface of burning flammable liquids, effectively suppressing the fire by separating the fuel from the air, thus reducing the vapor production and cooling the surface.

The effectiveness of AFFF in fighting fires, particularly those involving hydrocarbons, is attributed to its ability to create a barrier that inhibits re-ignition and allows for safer firefighting operations. This distinguishes foam agents from other types, such as gas agents, dry chemical agents, or water-based agents, which utilize different methods of fire suppression.

Gas agents, for instance, work by displacing oxygen or interrupting the chemical reaction of combustion, while dry chemicals typically act by providing a powdery substance that disrupts the fire triangle. Water-based agents mainly rely on cooling the fire and soaking potential fuels. Each agent type has its unique qualities and applications depending on the fire characteristics, but AFFF stands out for its foam characteristics specifically designed for liquid fuel fires.