What defines a body harness in fall protection systems?

A body harness in fall protection systems is defined by its ability to effectively distribute fall arrest forces over the body. This design is crucial for ensuring that if a worker falls, the impact forces are spread across larger areas of the body, reducing the risk of injury. The harness typically includes straps that go over the shoulders and around the legs, creating a secure fit that allows the worker to be safely restrained or arrested in the event of a fall.

The other options focus on specific aspects that do not adequately describe a body harness. For instance, a strap that attaches only at the waist would not provide the necessary support or safety; it would concentrate forces on a single area, which can cause injury. A single point of attachment for safety lines does not encompass the full definition of a harness, as a harness should have multiple attachment points to enhance safety and functionality. Finally, stating that it is only for workers on roofs limits the application and purpose of body harnesses, as they are used in various environments where there is a risk of falling, not just on roofs. Therefore, the comprehensive design and function of a body harness in fall protection are best captured by the ability to distribute fall arrest forces over the body.