When fighting a topside fire with CO2, from which direction should you approach and why?

• A. To avoid wind entirely
• B. To let CO2 drift over the fire
• C. To maximize wind into the space
• D. To keep CO2 away from crew

Answer: (B)

CO2 extinguishing relies on dense gas that blankets the fire by settling downward and spreading across the area. Because CO2 is heavier than surrounding air, it tends to drift over and around the flame, cooling it and displacing the oxygen needed for combustion. The best approach is from the upwind side so the released CO2 can drift over the fire and form that protective blanket, rather than being blown away or ineffective in a windier direction. This positioning makes full use of CO2’s tendency to settle and blanket the flame.