A ventilation-limited fire is characterized by being controlled by what and may surge with what action?

• A. fuel supply; added openings
• B. oxygen; added openings
• C. smoke production; removing openings
• D. temperature; ventilation changes

Answer: (B)

Ventilation-limited fire growth is driven by the oxygen available for combustion. When there isn’t enough oxygen, the fire can’t grow quickly even if fuel is abundant. Opening more vents or creating openings increases the oxygen supply, feeding the flames and raising the heat-release rate. This added ventilation can cause a rapid surge in fire behavior, sometimes tipping the fire into flashover or a much more dangerous state.

The other options don’t fit because they imply the limiting factor is fuel (not oxygen), or involve removing ventilation (which would typically dampen or slow the surge rather than cause a rapid intensification), or focus on temperature rather than the key limiting factor of oxygen availability.