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

The type of foam made from animal by-products is protein foam. This foam is generated from hydrolyzed animal proteins and is specifically designed to extinguish flammable liquid fires by forming a blanket over the surface of the liquid. The protein foam adheres better to surfaces than other types of foams and is particularly effective for fires involving hydrocarbons.

In contrast, aqueous film-forming foam and Class A foam are formulated from synthetic surfactants and are engineered to deal with different types of fire scenarios, primarily involving polar solvents and ordinary combustibles, respectively. Organic foam, on the other hand, does not specifically relate to animal by-products, as it generally encompasses various natural and synthetic materials. Therefore, protein foam is the clear choice when dealing with foams derived from animal sources.