U.S. regulations require a responsible person to be present at all times when the hatches of spaces containing Class 1 explosive materials are open. When is the responsible person released from the duty of attendance?

Correct Answer: Option D — when the hatches for the hold containing Class 1 Explosives have been secured

A designated responsible person must maintain continuous attendance at open hatches containing Class 1 explosives. This mandatory safety duty is only officially released once the hatches for that specific hold have been fully closed and secured.