What information should be recorded in zone designations (hot/warm/cold)?

• A. Boundaries
• B. Access control
• C. Boundaries, access control, and which areas are safe to work in vs. restricted
• D. Which areas are safe to work in vs. restricted

Answer: (C)

Zone designations in hot/warm/cold environments should record three pieces of information: the boundaries of each zone, who is allowed to enter (access control), and what parts are safe to work in versus restricted. Boundaries define the physical extent of the zone so crews know where it starts and ends and how to position equipment and personnel. Access control specifies who may enter each zone, helping maintain accountability and ensuring only trained personnel with the proper PPE operate there. Indicating which areas are safe to work in versus restricted communicates where routine salvage or overhaul tasks can proceed and where additional precautions, decontamination, or exclusion are required. Together, these elements provide clear, actionable guidance for safety, coordination, and risk management. Boundaries alone don’t tell who can enter or what work is allowed; access control alone doesn’t define the exact zone extents; and safe-to-work status alone doesn’t outline the entry requirements or boundaries.