Above-ground storage tanks (ASTs) can be classified as:

Above-ground storage tanks (ASTs) can indeed be classified as either pressurized or nonpressurized. This classification is significant because the design, construction, and safety considerations differ based on whether the tank holds liquids under pressure or not.

Pressurized tanks are engineered to contain fluids at pressures above atmospheric levels, which typically requires more robust materials and safety features to prevent leaks or ruptures. Nonpressurized tanks, on the other hand, operate at atmospheric pressure and generally have different structural requirements, as they do not need to withstand internal pressures.

This classification helps emergency responders and safety personnel identify the specific hazards associated with the tank's contents and ensure appropriate handling and response strategies are in place. Understanding the differences between pressurized and nonpressurized tanks is crucial in hazards assessment and emergency management scenarios related to hazardous materials.