What term refers to personnel who are not normally part of an explosives operation but require access?

The correct term referring to personnel who are not normally part of an explosives operation but require access is "casuals." This term specifically applies to individuals who may need to enter the area for brief periods or specific tasks, such as maintenance or inspections, without being regular members of the explosives handling team. Casuals typically do not have the same training or clearance as those directly involved in explosives operations, but their access is managed carefully to maintain safety protocols.

In contrast, contractors typically refer to individuals or organizations hired for specific projects and may have different credentials and training. Visitors are generally defined as people who come to observe or attend meetings but may not need access to the operational areas related to explosives. Volunteers, while they may support various activities, often do not have the required clearances and training to be involved in explosives handling unless specifically designated and trained for such duties. Thus, the focus on the specific roles and training requirements makes "casuals" the most accurate term in this context.