When is the use of unprotected EMT permitted?

Unprotected Electrical Metallic Tubing (EMT) is permitted to be used when it is installed in direct contact with the earth because this scenario allows for natural protection against physical damage from environmental elements. The fact that it is underground provides some inherent shielding from impact and corrosion.

Typically, unprotected EMT is not suitable for above-ground installations where it could be subject to physical damage. Similarly, using unprotected EMT indoors does not align with safety standards where risks from impacts or environmental exposure are present. Even painting EMT does not afford sufficient protection in critical areas such as outdoor or exposed settings, where a more resilient barrier is necessary to maintain integrity against potential hazards. Thus, its underground application is the only acceptable condition without additional protection.