Which of the following is NOT considered passive fire defense?

• A. Fire Walls and Doors
• B. Smoke Detectors
• C. Fire Doors
• D. Fire Suppression System

Answer: (D)

Passive fire protection consists of built-in features that don’t rely on power or action to work, creating barriers and compartmentation to slow or stop fire spread. Fire walls and doors, including fire doors, fit this idea because they are rated barriers that maintain integrity during a fire without needing detection or activation. Smoke detectors are active devices—they need power to operate and work by sensing smoke and triggering alarms. A fire suppression system is also active, responding automatically or manually to suppress the fire. Therefore, the option that is not passive is the fire suppression system.