Initial response ICS is implemented within the ____ of an incident.

• A. Second operational period (approximately 24 hours)
• B. First operational period (approximately 12 hours)
• C. During recovery phase
• D. After extended response activation

Answer: (B)

Initial response ICS is implemented within the first operational period, typically about 12 hours after the incident begins. This early activation creates the formal command structure, assigns the major sections (such as Operations, Planning, Logistics, and Finance/Administration), and starts the Incident Action Plan. Establishing ICS at this stage ensures coordinated decision-making, clear accountability, and safety as the incident moves from initial response toward extended operations or recovery. Later phases, like the second operational period or recovery, come after this initial setup when the incident demands ongoing management or when demobilization begins.