A Class Bravo Fire has been reported. What extinguishing agents are preferred?

A Class Bravo Fire has been reported. What extinguishing agents are preferred?

• A. Water
• B. Foam
• C. Dry chemical
• D. CO2

Answer: (D)

A Class Bravo fire involves flammable liquids, so the aim is to starve the flame of one of the fire triangle elements. In enclosed shipboard spaces, flooding with carbon dioxide displaces the ambient air, smothering the flame quickly by removing the oxygen it needs. This rapid knockdown is especially effective in compartments where you can seal the space and work with the crew to ensure safety. CO2 also leaves no residue that could damage sensitive equipment and requires less cleanup than some other agents. Water would spread the fuel and worsen the fire; foam blankets the liquid but takes longer to deploy and isn’t as immediate in a confined space; dry chemical works well on many Class B fires but can foul electronics and leave a powdery residue. So the fast, clean smothering action of CO2 in an enclosed space makes it the preferred choice here.

A Class Bravo fire involves flammable liquids, so the aim is to starve the flame of one of the fire triangle elements. In enclosed shipboard spaces, flooding with carbon dioxide displaces the ambient air, smothering the flame quickly by removing the oxygen it needs. This rapid knockdown is especially effective in compartments where you can seal the space and work with the crew to ensure safety. CO2 also leaves no residue that could damage sensitive equipment and requires less cleanup than some other agents. Water would spread the fuel and worsen the fire; foam blankets the liquid but takes longer to deploy and isn’t as immediate in a confined space; dry chemical works well on many Class B fires but can foul electronics and leave a powdery residue. So the fast, clean smothering action of CO2 in an enclosed space makes it the preferred choice here.