3.6 Fall Protection, Walking-Working Surfaces, & General Safety

Walking-Working Surfaces and Same-Level Falls

Slips, trips, and falls on the same level are among the most frequent causes of occupational injuries and workers' compensation claims.

• Slips occur when there is insufficient friction or traction between a person's footwear and the walking surface, often due to water, oil, ice, or highly polished floors.
• Trips occur when a person's foot strikes an object, causing a loss of balance. Common hazards include uneven floor surfaces, curled floor mats, uncovered cables, and poor housekeeping (clutter in walkways).

Mitigation relies heavily on administrative controls (routine housekeeping and inspection programs) and engineering controls, such as installing high-friction flooring, ensuring adequate lighting, and using cable management systems.

Elevated Work and Fall Protection Triggers

When employees are exposed to fall hazards from elevations, employers must implement fall protection. The height at which this protection becomes mandatory depends on the industry:

• General Industry: 4 feet
• Shipyards: 5 feet
• Construction: 6 feet
• Scaffolding: 10 feet
• Steel Erection: 15 feet (or up to 30 feet for certain connectors)

Notably, regardless of the height, fall protection must be provided when working above dangerous equipment, such as vats of acid, conveyor belts, or machinery with exposed moving parts.

Passive vs. Active Fall Protection

Safety professionals prioritize fall hazard elimination (e.g., lowering the work to ground level). When elimination is not feasible, protection systems are divided into passive and active categories.

Passive Systems

Passive systems are stationary and require no action from the worker to function. They are generally preferred because they eliminate human error.

1. Guardrails: The standard guardrail consists of a top rail, midrail, and toeboard.

   • Top Rail: Must be 42 inches (± 3 inches) above the walking surface and capable of withstanding 200 pounds of downward or outward force.
   • Midrail: Installed midway between the top rail and the floor (typically 21 inches) and capable of withstanding 150 pounds of force.
   • Toeboard: Minimum of 3.5 inches high, capable of withstanding 50 pounds of force, designed to prevent tools and materials from falling onto workers below.

2. Safety Nets: Installed underneath elevated work areas (e.g., bridge construction). Nets must be installed as close as practical under the walking/working surface, but never more than 30 feet below. They must be drop-tested using a 400-pound sandbag before use.

3. Hole Covers: Used to cover floor openings or skylights. Covers must be color-coded or marked "HOLE" or "COVER" and must be capable of supporting at least twice the weight of employees, equipment, and materials that may be imposed on the cover at any one time.

Active Systems: Personal Fall Arrest Systems (PFAS)

When passive systems are impractical, an active Personal Fall Arrest System (PFAS) is used. A PFAS does not prevent a fall; it arrests (stops) a fall in progress and minimizes the physical forces exerted on the worker's body. A PFAS requires active participation from the worker (donning, inspecting, and tying off).

The "ABCs" of a PFAS are:

• A - Anchorage: The secure point of attachment. Under OSHA, anchorages used for personal fall arrest systems must be capable of supporting at least 5,000 pounds per employee attached, or be designed, installed, and used as part of a complete PFAS which maintains a safety factor of at least two under the supervision of a qualified person.
• B - Body Wear: A full-body harness. OSHA prohibited the use of body belts for fall arrest in 1998 because belts concentrate arresting forces on the abdomen, causing severe internal injuries.
• C - Connecting Device: The link between the harness D-ring and the anchorage. This is typically a shock-absorbing lanyard or a self-retracting lifeline (SRL). Shock-absorbing lanyards are designed to limit the maximum arresting force on a worker's body to 1,800 pounds.

Calculating Fall Clearance

A critical component of planning a PFAS is ensuring adequate fall clearance—verifying the worker will not strike the lower level before the fall is completely arrested.

When using a standard 6-foot shock-absorbing lanyard, the calculation must account for:

• Lanyard Length: Typically 6 feet.
• Deceleration Distance: The elongation of the shock absorber as it deploys (legally permitted up to 3.5 feet).
• Worker Height/Harness Stretch: Generally estimated at 5 to 6 feet.
• Safety Factor: An additional clearance margin, usually 2 to 3 feet.

Therefore, a worker using a 6-foot shock-absorbing lanyard tied off at D-ring height needs approximately 17 to 18.5 feet of clearance below the anchorage to safely arrest a fall without hitting the ground.

Suspension Trauma

Once a fall is arrested, a secondary hazard emerges: suspension trauma (orthostatic intolerance). If a worker is left suspended in a harness, the leg straps compress the femoral veins, restricting blood flow back to the heart. Blood pools in the lower extremities, leading to rapid drops in blood pressure, fainting, and potentially death within 15 to 30 minutes. Employers must have a prompt rescue plan in place to retrieve suspended workers immediately, and workers can deploy trauma relief straps (stirrups) to stand on, relieving pressure while awaiting rescue.