DOT specification containers shall be located and installed so that the discharge from the container pressure relief device is at least what distance below building openings?

The requirement for the placement of DOT specification containers, particularly concerning the distance below building openings, is primarily focused on safety considerations. The correct answer is three feet. This distance ensures that, in the event of a discharge from the pressure relief device, the gas can safely dissipate away from the building opening, minimizing the risk of gas accumulating near windows, doors, and other openings where it could pose a potential hazard.

By maintaining this three-foot distance, the design helps protect the structure and its occupants from unintended exposure to propane or other gases, which could lead to fire or asphyxiation in enclosed spaces. Implementing this specific distance is crucial for compliance with safety standards and regulations that aim to prevent incidents related to LP gas installations.

The other distances suggested do not align with industry standards as effectively as the three-foot requirement. A one-foot distance might still allow for gas accumulation near openings, while five and ten feet could be excessive in some contexts, leading to inefficient use of space without providing significant additional safety benefits.