Where falling objects threaten employees the employer requires hard hats and puts in place one of the measures meeting the falling object criteria of 1926.502(j): toeboards, screens or guardrail systems that keep objects from falling from higher levels; a canopy with potential falling objects kept far enough from the edge not to go over if displaced; or a barricaded area below that employees may not enter, with objects kept back from the edge. Employees working below holes in walking and working surfaces, skylights included, are shielded from anything falling through by covers meeting the cover criteria or an equivalent.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.