Which option best describes the effect of indirect attack using ventilation and steam conversion?

• A. Increases heat.
• B. Expands fuel supply.
• C. Cools and dilutes the fire through ventilation and steam conversion.
• D. Reduces oxygen by starving the fire.

Answer: (C)

Indirect attack with ventilation and steam conversion cools the fire and dilutes the combustible gases. When water is applied and steam forms, a large amount of heat is absorbed as the water becomes steam, lowering the temperature of the flames, hot gases, and surfaces. At the same time, the steam fills the space and dilutes the fuel vapors, reducing the concentration of flammable gases and making the environment safer and less prone to rapid flame spread. This combination slows the fire and supports a safer interior attack. It’s not about increasing heat, it doesn’t add fuel, and while some oxygen is displaced by steam, the defining effect is cooling and dilution.