Once the span of control rises above what number, should the IC include an ISO?

The inclusion of an Incident Safety Officer (ISO) becomes essential when the span of control exceeds three. In the context of incident command, the span of control refers to the number of individuals or resources that one manager or supervisor can effectively oversee.

When the span of control is limited to three or fewer, a single incident commander can maintain effective communication and oversight, ensuring that tasks are being executed safely and efficiently. However, as the number of personnel increases, the complexity of managing safety also rises due to potential distractions, the increased likelihood of misunderstandings, and the greater variety of tasks being performed.

At this point, an ISO becomes critical to focus specifically on the safety aspects of the operation, allowing for dedicated oversight of safety-related concerns. The ISO can help in identifying hazards, ensuring compliance with safety protocols, and fostering a culture of safety among the team. This ensures that the incident commander can concentrate on broader tactical decisions without being overwhelmed by safety management in a more complex operational environment.