The Hidden Danger of Swing Hazards in PFAS Use
When employees work at height, a Personal Fall Arrest System (PFAS) is often the last line of defense between a worker and serious injury or death. But even when properly anchored, harnesses and lanyards introduce a less obvious—but equally dangerous—risk: the swing hazard.
Too often overlooked, swing hazards can subject workers to extreme forces, collisions, and serious injuries if not properly controlled. Understanding this hazard, and the limits of your fall protection equipment, is critical for any workplace safety program.
What Is a Swing Hazard?
A swing hazard occurs when a worker moves laterally away from their anchor point, creating an angle in the lanyard or self-retracting lifeline (SRL). If a fall occurs, the worker will not only fall vertically but will also swing like a pendulum toward the anchor point.
This swinging motion can cause a worker to collide with beams, equipment, guardrails, or other structures. The hazard is especially severe when walking parallel to an edge while tied off to a retractable lanyard—the line pays out, but the anchor point remains fixed, creating a wide swing arc.
Maximum Forces and Equipment Ratings
Fall protection systems are designed with strict limits on maximum arresting force. OSHA requires that no more than 1,800 pounds of force be transmitted to a worker during fall arrest when using a full body harness (29 CFR 1926.502(d)(16)(iii)).
Manufacturers test equipment under straight-line forces—essentially, a fall directly under the anchor point. Swing falls add unexpected side loading to anchors, connectors, and SRLs, which can dramatically increase forces beyond tested conditions. In some cases, swing angles of just 30 degrees can double the forces applied to the anchor.
If the worker collides with a structure during the swing, the forces of impact are in addition to fall arrest forces—resulting in broken bones, internal injuries, or worse.
Maximum Permitted Working Angles
ANSI Z359 guidance recommends that workers stay within 30 degrees of the anchor point to minimize swing hazard risk. Beyond this angle, the pendulum effect becomes severe, and the risk of collision or excessive forces grows rapidly.
In practical terms, this means anchors should be positioned directly overhead whenever possible. Side or low anchors should be avoided unless the system has been specifically engineered and rated for such use.
Walking Parallel to an Edge with a Retractable Lanyard
Self-retracting lifelines (SRLs) are often seen as safer than fixed lanyards because they reduce free-fall distance. However, they can create a false sense of security when workers walk parallel to an unprotected edge.
As the SRL extends, the worker drifts farther from a straight-line path under the anchor. If a fall occurs, the SRL will lock—but the worker will pendulum into the structure or edge. Worse, if the edge is sharp, the SRL line may not be rated for sharp-edge use, risking catastrophic line failure.
For this reason, walking side-to-side along an edge should only be done when:
The anchor point has been properly selected to minimize swing.
The SRL is rated for sharp edges if there is contact risk.
Engineering or administrative controls (like guardrails or limited-access zones) reduce exposure.
Best Practices for Controlling Swing Hazards
Anchor Placement Matters
Always place anchors directly overhead when possible. Side or low anchors should be considered last-resort options and engineered by a qualified person.Stay Within 30 Degrees
Limit movement to within a 30-degree radius from the anchor point to keep swing forces manageable.Use the Right SRL for the Job
Sharp-edge-rated SRLs are critical if there’s a chance the line could contact an edge during a swing.Train and Reinforce
Workers should be trained to recognize when their movement is creating a swing hazard, especially when walking parallel to an edge.Evaluate Hazards in the Job Hazard Analysis (JHA)
Every task at height should include swing hazards as part of the fall protection review.
Final Thoughts
Swing hazards are often underestimated, but they can be just as deadly as a free fall. A PFAS is only as safe as the way it’s used—and overlooking swing hazard means overlooking a serious, preventable risk.
By respecting maximum forces, staying within safe working angles, and properly training workers, companies can ensure that fall protection truly protects, instead of introducing new dangers.
