Which of the following is NOT a reason for regulating access during explosives operations?

Regulating access during explosives operations is primarily focused on ensuring safety, security, and operational efficiency. Safety of personnel involves minimizing the risk of accidents and injuries in potentially hazardous environments. Security of materials is crucial to prevent theft, sabotage, or any unauthorized access that could lead to dangerous situations. Efficiency of operations ensures that the handling and use of explosives can be conducted without unnecessary delays or complications.

Improvement of public relations, while important in many contexts, is not a direct reason for regulating access during explosives operations. Public relations may be a secondary consideration that emerges from effectively managing the first three priorities, but it does not serve as a critical motive in the context of operational protocols and safety concerns associated with explosives. Therefore, this option stands apart from the core reasons for regulating access during these operations.