What is the primary purpose of using Class A foam in firefighting?

The primary purpose of using Class A foam in firefighting is to extinguish smoldering fires. Class A foam is designed to work specifically on ordinary combustible materials, such as wood, paper, and some textiles. It enhances water’s effectiveness by reducing its surface tension, allowing it to penetrate materials more easily and cool them down. This characteristic is particularly useful in dealing with smoldering materials or fires that are difficult to extinguish completely with water alone.

While Class A foam can assist in various ways, its primary role is focused on cooling and smothering fires in fuels that are burning or smoldering. The foam forms a blanket that can smother hot embers, a key aspect in preventing reignition and ensuring a thorough extinguishment. This function makes it especially valuable in structural firefighting, where materials may continue to smolder and pose a risk of flare-ups if not properly treated.