What particular danger is present if ventilation is restored following an explosion, before an exploration is made?

Restoring ventilation immediately after an explosion can significantly revive dormant fires or ignite unburned flammable materials, creating a heightened risk of subsequent explosions. When such an incident occurs, there is often a mixture of gases and potential combustion materials that can become volatile if airflow is increased. This can lead to a rapid spread of those gases, creating an explosive atmosphere.

During an explosion, there may be unignited combustible gases or materials that are temporarily stabilized due to the lack of airflow. By restoring ventilation, these materials can be subjected to oxygen, which can reignite flames or create new fire risks, potentially leading to a secondary explosion. This is why thorough exploration and assessment of the situation should be completed first, to ensure any remaining hazards, such as fires or explosive atmospheres, are adequately addressed before introducing fresh air into the environment.

The other answers point to legitimate safety concerns, but they do not carry the same immediate and potentially catastrophic implications as the risk of reviving dormant fires and causing further explosions.