Emergency exit signs must be visible under what circumstances?

The requirement for emergency exit signs to be visible under normal and emergency conditions ensures that they serve their critical purpose effectively at all times. In non-emergency situations, these signs help familiarize occupants with the layout of the building and the locations of exits. During an emergency, visibility becomes even more crucial, as occupants may need to evacuate quickly under conditions that could include smoke, darkness, or disorientation.

By needing to be visible at all times, including when the power fails (as would be the case in many emergencies), the signs must be illuminated by reliable means, such as battery backups or photoluminescent materials. This guarantees that everyone, regardless of the conditions, can clearly see the exit signs, facilitating safe egress and minimizing chaos during critical moments.

The other options do not encompass the comprehensive safety needs of all situations regarding emergency exit signs, limiting their potential effectiveness in life safety scenarios.