Introduction of ice inhibitor will lower the flash point of JP-5 by?

• A. 2 degrees F
• B. 4 degrees F and inhibit bacteria growth
• C. 6 degrees F
• D. No change to flash point

Answer: (B)

Ice inhibitor additives in JP-5 do two practical things: they can shift the fuel’s flash point and they help prevent microbial growth in the fuel-water mixture. The flash point is the lowest temperature at which fuel vapors can ignite in air. Introducing the inhibitor adds components that alter the fuel’s vapor pressure, so flammable vapors reach the ignition concentration at a lower temperature—typically about four degrees Fahrenheit for this additive. At the same time, the additive often includes biocidal or microbe-suppressing properties, which inhibit bacteria growth in the fuel system. This dual effect is why the correct choice states a four-degree Fahrenheit drop in flash point and inhibited bacterial growth.