Final answer:
A warning line is employed to warn workers of approaching an unprotected edge, serving as a visual cue for maintaining safety distances from potential fall hazards.
Step-by-step explanation:
The purpose of a warning line is primarily to alert workers that they are approaching an unprotected edge, which could lead to a dangerous fall or other injury. The warning line serves as a visual cue to prevent accidents by ensuring that workers remain at a safe distance from potential hazards. It is not intended to designate an area where work can occur without other forms of fall protection, nor is it designed to allow workers to safely lean over an edge, nor does it limit the free fall in the event of a fall.
Always keep workplace safety rules, such as those enforced by the Occupational Safety and Health Administration (OSHA), in mind which may include providing fall protection like guardrails or safety harness lines, preventing exposure to hazards, ensuring the use of personal protective equipment (PPE), and offering safety training in appropriately understandable languages and vocabularies for workers.