This section applies to fences, railings, and perimeter guards.
This standard provides precise safety distances based on anthropometric data—specifically the reach and size of the human body—to prevent contact with hazards. iso 13857 pdf
If a guard has a slot of 12mm or less, a finger cannot pass through it effectively. However, if the slot is 20mm, a finger can pass through, and the guard must be placed a specific calculated distance away from the hazard to prevent the finger from touching the danger zone. This section applies to fences, railings, and perimeter