Final answer:
Accidents during ladder handling are most likely when setting up the ladder and while climbing up or down, emphasizing the importance of safety measures.
Step-by-step explanation:
During ladder handling, accidents are most likely to occur when placing the ladder in position and when a person is ascending or descending the ladder. The probability of accidents is a concern addressed in occupational safety, and measures are taken to reduce the likelihood of such events. The time of setup, which involves ensuring the base is stable and properly secured, and the time when workers interact with the ladder, which includes climbing up or down, are critical moments where adherence to safety protocols is essential to prevent injuries or worse. Failure to follow instructions and inadequate ladder usage often constitute significant risk factors. While not usually calculated in day-to-day operations, understanding the risks and implementing best practices can greatly reduce the incidents of ladder-related accidents.