The assignment of an ISO at a hazmat technician-level incident is:

The assignment of an Incident Safety Officer (ISO) at a hazmat technician-level incident is required by law, reflecting the critical importance of safety in hazardous materials response situations. Under regulations such as the Occupational Safety and Health Administration (OSHA) standards, particularly in relation to emergency response operations involving hazardous materials, it is mandated to have safety personnel in place to ensure the well-being of all responders. The ISO is responsible for monitoring safety conditions, identifying potential hazards, and making informed decisions to protect the health and safety of all personnel involved in the incident. This legal requirement underscores the necessity of having a dedicated safety oversight role during complex and potentially dangerous operations to mitigate risks effectively.