When must personal fall arrest systems be used for employees working on poles or towers?

Personal fall arrest systems are critical for ensuring the safety of employees working at heights, particularly on poles or towers. The requirement for using these systems is set forth by safety regulations that aim to minimize the risk of falls, which can lead to serious injury or death.

In this context, the correct choice indicates that personal fall arrest systems must be employed when working at or above four feet in environments where workers are exposed to fall risks. This standard reflects a well-established safety protocol aimed at protecting those who are working in potentially hazardous conditions, especially in the electrical field where the nature of the work often involves elevated positions.

The four-foot threshold is specifically noted to ensure that workers are adequately protected as they perform tasks that inherently involve risk. This approach helps to enforce a proactive safety culture, encouraging employers and employees alike to recognize the importance of fall protection measures as soon as the height of four feet is reached.