What is the primary agent found in a Class A fire extinguisher?

The primary agent found in a Class A fire extinguisher is water. Class A fire extinguishers are specifically designed to combat ordinary combustible materials such as wood, paper, and cloth. Water is effective in extinguishing these types of fires because it cools the burning material and reduces the temperature below its ignition point.

Using water in these extinguishers works by applying a cooling effect to the flame, which not only extinguishes the fire but also helps to prevent re-ignition. It is important to note that Class A extinguishers are typically marked with a distinctive green triangle symbol, indicating their purpose for ordinary combustibles. Because of their effectiveness against common materials, water is the most utilized extinguishing agent in Class A extinguishers.