Persons not normally part of an explosives operation, but have duties requiring their presence, defines a ___.

• A. Guest
• B. Casual
• C. Contractor
• D. Observer

Answer: (B)

The main idea is identifying someone who isn’t part of the explosives operation as a normal crew member, but whose duties require them to be present. That label is “casual.” It marks a temporary, duty-based presence rather than active participation in the task. A casual is there for a specific purpose tied to their role, and safety controls and supervision apply accordingly.

Why this fits best: it distinguishes a person who must be on site for a defined reason from someone simply visiting (guest), someone there to observe without participating in tasks (observer), or someone involved in the work through a contract (contractor). The casual designation acknowledges limited involvement and emphasizes that their presence is authorized for particular duties, not as part of the operation crew.