Which statement describes the effect of ice inhibitor on JP-5?

• A. Lowers by 2 degrees F
• B. Increases flash point
• C. No change
• D. Lowers by 4 degrees F and inhibits bacteria growth

Answer: (D)

Ice inhibitor in JP‑5 works by two main actions: it lowers the temperature at which water in the fuel can start to freeze, and it suppresses growth of bacteria in the water phase. The freezing-point depression is typically about 4 °F, which helps prevent ice crystals from forming in cold conditions and clogging fuel systems. At the same time, the additive has bacteriostatic properties, reducing microbial growth that can cause sludge or corrosion in the fuel system. This combination explains why the statement describing a roughly 4 °F cut in the ice formation point and a inhibition of bacterial growth best fits how the additive behaves. It does not raise the flash point, and the effect is not “no change.”