Aboveground containers shall be ________.

Aboveground containers must be painted primarily to enhance safety and longevity. Painting these containers serves multiple purposes: it provides protection against corrosion and environmental factors like UV rays, which can degrade the material over time. Additionally, bright colors, such as safety yellow or other high-visibility colors, can increase the visibility of the containers, reducing the risk of accidental collisions or damages, especially in areas where vehicles or heavy equipment operate. Proper painting also plays a role in maintaining the integrity of the propane container, as it helps prevent rust and other forms of deterioration that can cause leaks or other safety hazards.

The other options involve actions that do not align with the regulations or best practices for handling aboveground propane containers. Buried containers might suggest a different set of guidelines and maintenance responsibilities than those applied to aboveground units. Similarly, underground installation contradicts the premise of an aboveground container, while heavy insulation is not required for safety purposes relative to the handling and storage of propane in aboveground configurations.