USCG Firefighting License Practice Exam

After extinguishing a fire in a paint locker with a fixed CO2 system, the appropriate action is to leave the space closed with vents off until all boundaries have cooled. This is critical because CO2 displaces oxygen and can create a suffocating atmosphere. By keeping the space sealed, you ensure that any remaining flammable vapors are contained and that the likelihood of reignition or reflash is minimized.

Allowing the space to remain closed until everything is cool prevents any potential hazards from developing due to fluctuations in temperature or the introduction of fresh air, which could reignite the fire. Monitoring the temperature ensures that the area does not retain enough heat to start the fire again. This approach is standard procedure to secure the area, allowing for a safe and controlled environment after firefighting operations.

In contrast, other options might not adequately address the risks associated with a post-fire environment. Opening the space prematurely might expose it to oxygen and lead to re-ignition. Checking for oxygen content, while important in some cases, is better approached after ensuring the area has stabilized; it is typically done in conjunction with ensuring that the area is cool. Dousing with water could introduce the possibility of reflash from existing heat sources.