What Does
Leading Edge Mean?
A leading edge is the unprotected edge of a roof, floor, or other walking-working surface that is under construction. The leading edge changes location as work on the surface progresses.
Unlike finished edges, leading edges are often sharp or abrasive. This can damage and impair the function of fall protection equipment, creating a unique hazard for workers.
Safeopedia Explains Leading Edge
The Occupational Safety and Health Administration (OSHA) defines a leading edge as:
“The edge of a floor, roof, or formwork for a floor or other walking/working surface (such as the deck) which changes location as additional floor, roof, decking, or formwork sections are placed, formed, or constructed.”
Since leading edges are unfinished, they present hazards not typically found with other types of edges, including:
- Sharp edges that could sever the lifeline
- Jagged edges that could saw through the lifeline when a worker is suspended and swinging after a fall
- Overhead anchorage is not always available, forcing workers to tie off at foot level, which can increase the free fall distance required before the self-retracting lifeline (SRL) engages and arrests the fall
- The most effective fall protection methods (like guardrails) often cannot be used because workers need to work on the leading edge itself
Leading Edges in the Construction Industry
Working at a leading edge is an integral part of the construction process. An edge is considered a leading edge if it meets these three conditions:
- There is active construction work taking place at the edge
- The edge is unprotected (there are no guardrails or barriers)
- There is a risk of falling off the edge
Leading edges may be present in a number of different construction jobs, including:
- Concrete decking
- Laying floor panels
- Aerial lift work
- Roof decking
- Precast bridge assembly
- Steel erection
- Glass installation
- Excavation
- Installing metal decking
Regulatory Guidelines for Leading Edges
OSHA fall protection standards for the construction industry are covered in:
Fall protection measures that might be needed near leading edges include:
ANSI Standards for Fall Protection Systems
The American National Standards Institute (ANSI) covers fall protection systems in its Z539.14-2021 standard. It defines two types of self-retracting devices for fall arrest systems: Class 1 and Class 2.
Only Class 2 SRLs are designed and rated for use in leading edge applications. While Class 1 devices can only be anchored above the dorsal D-ring of the safety harness, Class 2 devices can be tied off below that level. Class 2 SRLs also have lifelines made of materials that can withstand sharp edges.
Employer’s Responsibility
OSHA 1926.501(a) requires employers to implement adequate fall protection measures wherever workers are at risk of falling from a height of 6 feet or higher.
Employers must ensure a working environment free of known dangers, provide personal protective equipment (including personal fall arrest systems) at no extra cost to the employee, and train workers in identifying and managing fall hazards.
What Is Leading Edge Fall Protection?
Leading edge fall protection refers to safety measures and equipment used to prevent workers from falling while doing leading edge work, or to limit the risk and severity of injury if they do fall.
Leading Edge SRL (Class 2 SRL)
Class 2 self-retracting lifelines are designed to address:
- The risk of injury due to the force of the fall
- The risk of severing the lifeline on an unfinished edge
SRLs are designed to decelerate a fall and absorb some of the fall’s energy, thereby limiting the impact on the user’s body. SRLs must have a Class 2 rating when used in situations where the anchor point is below the level of the dorsal D-ring or where there could be a sharp edge.
Leading Edge Lanyards
The lanyard is a short, flexible rope with connectors at either end. It connects the body harness to the anchorage and bears the greatest force during a fall. Leading edge lanyards are specially made to resist damage due to friction and fraying when a fall occurs over a sharp leading edge.
Leading Edge Horizontal Lifeline Systems
Overhead anchor points are ideal when working near leading edges, but they are rarely available. Often, the work takes place where the only available anchor points are at foot level. This must be taken into consideration when selecting the components of a fall arrest system. In particular, the lifeline must be one that is suitable for tying off at foot level.
How to Install Leading Edge Devices
While working on a leading edge, workers must use an active fall protection system, including a full body harness and lanyard with an energy absorber.
Selecting and using the right anchor point is essential. Connectors or slings can be wrapped around concrete columns or several dowels of rebar if embedded connections especially meant for use as anchorage points are not available. The anchor must be fixed securely to ensure it remains sturdy and stable when subjected to the force of a fall.
The anchor point must be setback by at least five feet from the leading edge. This allows the fall arrest system to activate quickly in the event of a fall.
ANSI Compliance for Leading Edge Devices
Manufacturers of leading edge fall protection equipment must subject their devices to ANSI’s Dynamic Performance Test and Dynamic Strength Test to make them compliant with safety regulations.
- Dynamic Performance Test: A test mass that weighs 282 pounds is attached to the device and then subjected to a fall with a swing for 10 seconds. An additional load of 675 pounds is added after the drop.
- Dynamic Strength Test: A test mass that weighs 200 pounds is attached to the device and then subjected to a fall with an unrestrained swing for two minutes.
These tests are conducted in different atmospheric conditions, including hot and cold temperatures. To achieve compliance, the device must pass a minimum of 12 leading edge tests.
ANSI Z359.14-2021 is the most stringent standard for leading edge devices. It specifies criteria for self-retracting devices used in leading edge applications, such as:
- The ability to withstand an edge radius as sharp as 0.005 inches (0.13 mm)
- The ability to tie off safely at foot level
- An integral shock-absorber on the end that connects to the user’s harness
Additional Tips for Protecting Workers at Leading Edges
How Close to the Leading Edge Is Too Close?
Any work taking place on a surface with a leading edge will require special consideration. Even workers who aren’t doing work on the leading edge itself will need to be protected while in the vicinity of such edges.
1926.501(b)(2) specifies that work within 6 feet of a leading edge requires the installation of conventional fall protection equipment, and work between 6 and 15 feet of a leading edge requires the work area to be demarcated with hazard warnings posted at the six-foot mark.
OSHA, however, does not specify a safe distance from leading edges. As such, anyone working on a surface where leading edge work is taking place should be provided with fall protection equipment.
Guardrails and Signage
In addition to fall arrest systems, guardrails and warning signs must be used to prevent workers from wandering too close to a leading edge. The transition from safe or completed areas to unprotected leading edges must be marked with clear signs and barriers. The barriers must be a minimum of six feet from the leading edge, while the signs must indicate the need for a personal fall arrest system when entering the area.
Leading edges change positions over the course of a construction project. The guardrails must be moved accordingly to ensure that they are always at least six feet from the edge. They can also be repositioned to provide workers who are working on the surface (but not on the leading edge) more room to do their jobs.
Toeboards
A toeboard is a short protective barrier installed on the edges of any raised area where there is a risk of objects falling off the edge. It is usually made of wood or metal and runs horizontally along the edge to act as a barricade. While sizes vary, they are typically between 4 and 12 inches high.
They can also act as a fall protection measure, especially on sloped roofs. If a worker loses their footing and is at risk of sliding off the roof, they can catch themselves by bracing their foot against a secure toeboard.
Toeboards can be installed on roofs, as well as holes, ramps, walkways, scaffolding, and other unprotected edges.
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