How do you effectively isolate a fire to prevent its spread?

• A. Close doors to compartmentalize, shut off utilities if safe, and establish boundaries to prevent cross-ventilation.
• B. Open all doors to vent smoke.
• C. Spray water everywhere.
• D. Ignore the fire and evacuate.

Answer: (A)

Isolating a fire is about using the building’s layout to limit its spread. By closing doors, you create barriers that trap heat and smoke in the area of origin, slowing the flames and giving you time to evacuate and for responders to act. If it’s safe, shutting off utilities reduces potential fuel sources and eliminates hazards that could feed or propagate the fire. Establishing boundaries and preventing cross-ventilation reduces the air supply feeding the fire and keeps other parts of the building safer. Together, these steps slow the fire’s growth, limit smoke spread, and preserve options for a controlled response.

Opening doors to vent smoke would feed the fire and push it into additional areas. Spraying water indiscriminately can be ineffective, unsafe, or cause other hazards, and simply ignoring it while evacuating leaves the fire unchecked and can allow it to grow.