Final answer:
Materials and equipment must be stored at least 6 feet from any working edge when using guardrail systems, to ensure safety and compliance with OSHA regulations.
Step-by-step explanation:
When using guardrail systems, materials and equipment must be stored at least 6 feet from any working edge. This distance ensures that the material doesn't create a hazard for employees by potentially falling over the edge, and it also maintains the integrity and effectiveness of the guardrail system in protecting workers from falls. Note that for construction sites, the Occupational Safety and Health Administration (OSHA) sets forth this specific distance to prevent materials, tools, or other equipment from causing a tripping or falling hazard near unprotected edges.