What does the saponified film reduce to prevent re-ignition?

• A. It reduces the rate of oil evaporation.
• B. It reduces oxygen in the area.
• C. Evaporation of oil.
• D. It increases ignition tendency.

Answer: (C)

The saponified film works by forming a soapy layer on the surface of the oil. This film seals the surface and blocks vapor from escaping, which lowers the rate at which oil evaporates. With fewer flammable vapors in the air above the oil, the chance of re-ignition decreases. While cooling and smothering effects help, the primary action for preventing re-ignition is the reduction in oil evaporation. So the film’s main impact is reducing evaporation of oil.