Why is it important to paint the upper two-thirds of a cargo tank in a reflective color?

Painting the upper two-thirds of a cargo tank in a reflective color is vital primarily for safety reasons. Reflective colors help to mitigate the absorption of heat from the sun, which can significantly reduce the temperature of the tank and its contents. When tanks absorb too much heat, it can cause pressure buildup within the tank due to the expansion of the liquefied petroleum gas (LPG) inside. This pressure increase can create safety hazards, including potential leaks or even explosions.

Additionally, reflective colors enhance visibility, especially in varying light conditions or during low visibility situations. This visibility is crucial during loading and unloading operations, as well as when the tank is in transit, to alert operators and other personnel to the presence of the tank, thereby reducing the risk of accidents or collisions.

The other options, while potentially relevant in different contexts, do not encompass the primary safety focus that reflective painting serves in this case.