Which material is NOT suitable for guardrails in a guardrail system?

Ropebanding is not suitable for guardrails in a guardrail system because it lacks the structural strength and durability required to provide effective fall protection. Guardrails are designed to prevent individuals from falling off elevated surfaces and must be capable of withstanding significant force. Materials like metal piping, wooden planks, and railings are robust enough to meet safety standards and regulations. Metal piping, for instance, is commonly used due to its strength and resistance to environmental factors, while wooden planks can also provide sufficient support when properly installed. The primary purpose of a guardrail is to ensure safety, which requires materials that can maintain their integrity under stress, making ropebanding an inadequate choice.