What is the purpose of a fire door and why must it be kept closed?

• A. To compartmentalize fire and smoke, protecting egress paths and limiting spread.
• B. To maximize air flow and speed up fire spread for testing.
• C. To let smoke circulate freely to improve visibility.
• D. To provide decorative entryways that don't influence fire behavior.

Answer: (A)

Fire doors are part of a building’s compartmentation system. They are designed to slow or stop the spread of fire and smoke between separate spaces, protecting escape routes and preserving the usability of stairs, corridors, and other egress paths. When a fire door is closed, it restricts heat, flames, and toxic smoke from moving from one room to another, helping keep areas tenable for occupants to evacuate and giving firefighters better conditions to operate. That’s why these doors are typically self-closing and must be kept shut; if they’re propped open, the barrier is lost and fire can spread much faster, compromising safety. Some doors have weather seals and insulation to improve their effectiveness, and only authorized hold-open devices should be used if a door must stay open for a legitimate reason.