When can the air support unit respond to a hazardous material incident?

The air support unit can respond to a hazardous material incident only when directly requested by unified command because this ensures that their deployment is coordinated and appropriate for the specific circumstances of the incident. Unified command is responsible for making strategic decisions regarding resource allocation and emergency response, particularly in complex scenarios such as hazardous material incidents where the safety of responders and the public must be prioritized. Proper coordination avoids overlap with other resources and allows for an effective response tailored to the unique challenges posed by the hazardous materials involved.

The other options do not align with the protocols governing the activation of the air support unit, as their response should not be based on individual assessments, visible threats, or routine patrols without the necessary request and coordination from unified command. This structured approach is critical for maintaining operational efficiency and safety at hazardous material incidents.