Deck General · Extinguishing Agents
When fighting a Class B fuel oil fire in the engine room with a CO2 extinguisher, you should direct the discharge:
- ADirectly at the base of the flame from as close as possible✓ Correct
- BAt the top of the flame to cool the hot gases
- CAt the base of the fire from outside the door before entering
- DAt the overhead above the fire to create a CO2 cloud that descends
Explanation
CO2 should be directed at the base of the fire — the interface between the liquid fuel and the flame — to smother the combustion zone and displace oxygen at its source. Aiming at the top of the flame or the overhead is ineffective because the agent disperses before reaching the fuel. Approach as close as safe to maintain agent concentration at the fire base, but never enter without SCBA.
Authority: Firefighting (USCG deck topic)
Practice the full Deck General bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Deck General questions
- Extinguishing Agents
Which method of fire extinguishment does water primarily use when applied as a straight stream to a Class A fire?
- Extinguishing Agents
Why should a straight water stream NEVER be applied to a Class B (flammable liquid) fire?
- Extinguishing Agents
CO2 extinguishes fire primarily by which mechanism?
- Extinguishing Agents
Dry chemical extinguishing agents (ABC dry chem) are most effective against Class B fires because they:
- Extinguishing Agents
Which extinguishing agent is appropriate for a Class C (energized electrical) fire?
- Extinguishing Agents
Aqueous Film-Forming Foam (AFFF) extinguishes Class B fires by: