Which fire class is specifically addressed with Class A foams?

Class A foams are specifically designed for use on combustible materials, such as wood, paper, and some plastics. These materials tend to ignite and produce a sustained fire when heated. Class A foams work by cooling the burning material and producing a barrier that helps prevent re-ignition, thus effectively suppressing these types of fires.

Combustible fires typically refer to those involving materials that can easily catch fire and sustain combustion, which is the exact scenario Class A foams are intended to address. The foams can penetrate and soak into the porous materials that are characteristic of many combustible fires, leading to successful extinguishment.

In contrast, electrical fires are addressed using different approaches and fire suppression agents, as water and foams can conduct electricity and create hazards. Flammable liquid fires, on the other hand, usually require Class B foams or other specific agents designed to suppress fires fueled by flammable liquids. Therefore, the focus of Class A foams clearly correlates to extinguishing fires involving combustible materials, which justifies the selection of this answer.