Explanation: When MPE (Maximum Permissible Exposure) power levels are present in an accessible area, it indicates an environment where occupational RF exposure limits must be observed. Personnel working in or accessing these areas need to be thoroughly trained on the potential hazards of RF energy, MPE limits, specific safety procedures, and proper mitigation techniques. To ensure this critical safety knowledge remains current, reinforced, and to address any changes in equipment, procedures, or regulations, annual training is a widely accepted and often required practice in RF safety standards. This regular refresher helps prevent complacency and ensures ongoing awareness of the hazards, contributing to a safe working environment. Weekly or monthly training would be excessively frequent and impractical for general MPE awareness, while no training at all would be negligent and dangerous, failing to protect personnel from potential RF hazards.