When is it acceptable to leave the barricade?

The correct answer emphasizes that it is acceptable to leave the barricade when rescued. In a coal mine or any hazardous environment, barricades are set up as a safety measure to protect workers from potential dangers or areas that are unsafe. The situation under which a worker should exit the barricade is tightly controlled to ensure safety.

Leaving the barricade during a rescue is justifiable because it implies that someone is coming to assist or evacuate the individual from a dangerous situation, which is crucial for their safety. In these scenarios, trained rescuers are involved, and they have the necessary equipment and knowledge to safely extract individuals from harm. Therefore, this answer underscores the importance of personal safety and the structured approach to emergencies within hazardous work environments.

In contrast, other situations like just completing safety training, receiving instructions from a supervisor, or leaving in a non-critical emergency might not guarantee the same level of safety and could potentially lead to exposure to risks. Each of these options lacks the assurance that proper rescue protocols are being followed, which is fundamentally why they do not apply in the same way as being rescued.