OSHA 10-Hour Construction ReviewFocus Four HazardsHard

A worker is installing pre-fabricated wall panels on a multi-story building. The panels are being lifted by a crane. Which of the following is considered a 'leading edge' that would require fall protection for workers installing them?

  1. AThe perimeter edge of a completed floor slab that is permanently fixed.
  2. BThe top edge of a wall panel before it is secured in place.
  3. CThe edge of a trench being excavated below ground level.
  4. DThe edge of a floor or roof that changes location as additional sections are installed.
Show answer & explanation

Correct answer: D. The edge of a floor or roof that changes location as additional sections are installed.

OSHA defines a 'leading edge' as the edge of a floor, roof, or formwork that changes location as additional sections are installed, becoming an unprotected edge over which an employee could fall. The scenario describes constructing a multi-story building with panels, meaning the floor/roof edge advances as work progresses, fitting this definition (1926.500(b)).

Why the other options are wrong

  • A. This is a fixed, unprotected edge, but not a 'leading edge' as it doesn't change location as work progresses.
  • B. While a fall hazard, the top edge of a wall panel is typically a vertical surface, not a horizontal 'leading edge' of a floor or roof.
  • C. This is an excavation edge, a fall hazard, but not specifically a 'leading edge' in the context of floor/roof construction.

Leading Edge (Fall Protection)

A 'leading edge' is an unprotected edge of a floor or roof that moves horizontally as construction progresses, requiring specific fall protection measures that can adapt to its changing location.

  • Workers at a leading edge are exposed to falls as the edge is created.
  • Fall protection for leading edges often involves personal fall arrest systems or safety net systems.
  • This is a specific type of 'Falls' hazard.

Memory trick: Leading Edge Moves, Holes Are Open, Scaffolds Elevate.

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