Adding wetting agents to water helps to extinguish a fire more efficiently than using water alone.
According to Internation Fire Protection, adding liquid concentrates to water increases its ability to spread and reduces the plain water's surface tension. Firefighters use foam, emulsifiers, and wetting agents to extinguish the other classified fires. Foam is the commonly used firefighter agent. Examples of the wetting agents are Dish Soap, Glycerin.
International Association for Fire Safety Science has conducted a series of tests to check the effectiveness of plain water and wet water on fire. The results show that wet water is more effective than plain water while extinguishing the fire in a closely packed bale of straw, but wet water was less effective on loosely packed straw. Wet water'ss effectiveness differs according to the object and the type of fire.