Which chemical is most widely used for fire suppression?

Water is the most widely used substance for fire suppression due to its availability, effectiveness, and low cost. It works by cooling the burning materials and reducing the temperature below the ignition point, which is crucial in stopping the combustion process. Water can absorb a lot of heat, making it particularly effective against many types of fires, including those involving ordinary combustibles such as wood, paper, and textiles.

While other agents like carbon dioxide, dry chemicals, and foam have specific applications and advantages in particular scenarios, they do not match the overall suitability and effectiveness of water for general fire suppression. For instance, carbon dioxide is effective in confined spaces but has limitations in open areas, and dry chemical agents are primarily used for flammable liquid fires or electric fires. Foam is beneficial for suppressing fires in flammable liquids but is not as versatile as water. Thus, water remains the primary choice for fighting a wide range of fires across various environments.