Where would you expect to find a "charged mist" on a tanker?

Correct Answer: Option D — In a cargo tank during "Butterworthing".

High-pressure water washing of cargo tanks, known as Butterworthing, generates a static-electrically charged mist. Under international safety standards (ISGOTT), this electrostatic hazard requires strict monitoring and inert gas protection to prevent ignition of flammable vapors in the tank.