During what period after a fire seal has been erected is there a danger of an explosion?

The correct answer highlights that the danger of an explosion persists as long as the oxygen content in the sealed area remains above 12%. This is crucial because the presence of oxygen is a key factor in the potential for combustion. In a sealed environment, if oxygen levels are sufficiently high, any residual heat from the fire or flammable materials could ignite, leading to an explosion.

After a fire seal is erected, it is essential to monitor the oxygen concentration. If it falls below 12%, the likelihood of an explosive atmosphere decreases significantly, as this concentration is below the minimum required for most forms of combustion to occur.

This understanding is critical for mine safety, as it informs workers and mine foremen about the necessary precautions to take during the first critical period after a fire incident, ensuring they maintain a vigilant approach regarding the atmosphere within the sealed area.