Which feature is essential to maintain egress safety when the building's primary power source fails?

• A. Regular door maintenance.
• B. Emergency lighting with battery backup.
• C. Fire suppression system.
• D. Security cameras.

Answer: (B)

When power fails, staying safe while exiting depends on illumination that stays on. Emergency lighting with battery backup is designed to operate independently of the building’s main power, automatically turning on to illuminate travel paths, exits, stairs, and exit signs. This visibility is what allows occupants to find their way to safety and helps responders move through the building during a blackout.

Regular door maintenance is important for ensuring doors function properly under normal conditions, but it doesn’t provide illumination or guidance when the power is out. A fire suppression system protects life by controlling flames, yet it doesn’t illuminate egress routes. Security cameras don’t assist with lighting or guiding people to exits during a blackout.