Which type of foam is made from animal by-products?

The correct type of foam made from animal by-products is protein foam. This foam is created through the hydrolyzing of proteins extracted from animal sources, which are then blended with water and air to produce a firefighting foam that is particularly effective on hydrocarbon fuels, such as oil and gasoline.

Protein foams form a thick, stable film that adheres to the surface of flammable liquids, helping to suppress vapors and prevent re-ignition. This characteristic makes them valuable in fighting fires involving flammable liquids, especially in industrial settings.

The other types of foam listed serve different purposes or are made from different components. For example, Class A foam is specifically formulated to combat ordinary combustible materials by reducing the surface tension of water, while aqueous film-forming foams (AFFF) are synthetic and designed primarily for use on polar solvents and hydrocarbon fires. Organic foam is a broader category that does not specifically refer to protein-derived products, making protein foam distinct in its composition and application.