Which suppression agent is most commonly used in residential fire extinguishers for Class A fires?

Water is the most commonly used suppression agent in residential fire extinguishers for Class A fires, which involve ordinary combustibles such as wood, paper, and cloth. The effectiveness of water as a suppression agent stems from its ability to cool the burning material, reducing its temperature below the ignition point. Additionally, water can penetrate these materials, providing thorough extinguishment.

In residential settings, where Class A fires are prevalent, fire extinguishers filled with water are typically more straightforward to use and accessible for the average consumer. They pose fewer concerns regarding toxicity or residue, making them suitable for household use. Overall, the combination of cooling properties and availability makes water the ideal choice for suppressing Class A fires in residential environments.