Which type of foam system is known for creating a film that suffocates the fire?

The Aqueous Film-Forming Foam (AFFF) is specifically designed to create a thin film that floats on top of the burning liquid, such as hydrocarbons. This film effectively suffocates the fire by cutting off the oxygen supply, which is crucial for fire combustion. The film also serves to suppress the release of flammable vapors, making it beneficial for protecting the surrounding area from fire spread.

AFFF works by allowing the foam to establish a continuous blanket over the burning surface, which is essential in extinguishing flammable liquid fires. This characteristic is what distinguishes AFFF from other types of foam systems.

Other foam types don't create this type of suffocating film. For instance, High-Expansion Foam generates large volumes of foam that expand and can fill spaces, but it does not specifically focus on forming a suffocating film. Fluoroprotein Foam can also be effective against flammable liquids but lacks the same film-forming capability as AFFF. Foam Film Type is not a standard classification used in fire protection, making it less relevant in this context. Thus, Aqueous Film-Forming Foam stands out for its unique ability to suffocate fires effectively by forming this important film.