Hazardous occupancies should be identified and evaluated:

• A. enroute to an emergency.
• B. during training sessions.
• C. at least once a year.
• D. during preincident planning.

Answer: (D)

The main idea is proactive risk assessment through preincident planning. Identifying and evaluating hazardous occupancies before an incident allows responders to know what they may encounter, assess the specific hazards (materials, quantities, potential release modes), and develop preplans, resource needs, and response strategies in advance. This readiness reduces uncertainty, speeds decision‑making, and improves safety for both responders and the public.

Why this timing is best: during preincident planning you can gather information, consult with occupancies, and build plans that account for the worst‑case scenarios without the pressure of an ongoing emergency. Waiting until en route to an incident leaves little time for thorough assessment or mitigation, when conditions are often unstable. Training sessions are important for learning concepts and procedures, but they don’t replace the need to identify real hazardous occupancies in advance. Relying on an annual check alone may miss changes in occupancy characteristics throughout the year; while reevaluation is important, the primary mechanism for recognizing and preparing for these hazards is the preincident planning process.