What type of agent is best used on a fire involving flammable liquids?

Sodium bicarbonate is an effective agent for extinguishing fires involving flammable liquids due to its properties as a dry chemical fire suppressant. When sodium bicarbonate is applied to a flammable liquid fire, it works by releasing carbon dioxide gas when heated, which helps to smother the flame and reduce the amount of oxygen available for combustion. This process effectively interrupts the fire's chemical reaction and helps control or extinguish the flames.

Understanding the other options provides insight into why sodium bicarbonate is preferable for this type of fire. Bromochlorodifluoromethane, while an effective halon, is not commonly used anymore due to environmental concerns. Water can exacerbate flammable liquid fires, as it can spread the burning liquid, leading to a larger fire. G-1 powder can be effective on certain classes of fire, but sodium bicarbonate is specifically suitable for flammable liquid fires due to its unique chemical reaction upon heating, making it a better choice in this scenario.