An employer must provide a guardrail in the following circumstances to ensure worker safety:

• Around every floor hole into which a worker can accidentally walk, to prevent possible falls through the opening.

• Around every open-sided platform, floor, or runway that is 4 feet (about 1.2 meters) or higher above the ground or next lower level, to stop workers from accidentally falling off the edge.

• Regardless of height, if a worker can fall into or onto dangerous machines or equipment below (such as vats of hazardous chemicals or moving machinery), a guardrail must be provided to prevent entry and injury in these areas.

These requirements follow workplace safety regulations and are intended to minimize the risk of severe workplace injuries due to falls or accidental exposure to dangerous environments. Safety regulations may specify additional requirements in some settings, such as construction sites, where fall hazards greater than 3 meters may also require guardrails if other safety solutions are not practicable.