Class A foam is characterized by having a lower what?

Class A foam is characterized by having a lower density compared to the materials it is meant to combat. This property is particularly important in firefighting as it enhances the foam's effectiveness in penetrating and cooling Class A materials, such as wood and paper, which are common combustibles. The lower density of Class A foam aids in its ability to form a thin film that helps displace air, reducing the oxygen available for combustion.

While considerations like viscosity, freezing point, and oxidizing potential are relevant in the broader context of firefighting and foam performance, they are not defining characteristics specific to Class A foam in the same manner as density. Lower density contributes fundamentally to the foam’s behavior and effectiveness, making it crucial for fire suppression strategies involving solid fuels.