Where a designer relies on guarding to control plant risk, the design must, as far as reasonably practicable, stop people reaching the danger area. The designer must follow this order: a permanently fixed physical barrier where access is not needed for operation, maintenance or cleaning; an interlocked barrier that lets people in only when the area is safe where access is needed; if neither is reasonably practicable, a barrier that can be altered or removed only with tools; and failing all three, a presence-sensing safeguarding system that removes the risk while someone, or some part of their body, is inside the guarded area. Guarding must be designed to make defeating or bypassing it, deliberately or accidentally, as hard as reasonably possible, and must not itself create a risk. Where moving parts could break or throw out workpieces, the guarding must eliminate that risk or, if that is not reasonably practicable, reduce it as far as reasonably practicable. Guarding may be removable for repair, servicing, maintenance and cleaning when the plant is not in normal operation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.