Implementing a proper fall protection plan is difficult. Here are the basics to give you a firm foundation on which to build your fall protection plan.

More than just a number – trigger heights

The legal need for fall protection is generally based on a trigger height, which can vary by industry.  For example, the most common trigger height from OSHA is for construction, at 6 feet. The trigger height drops to 4 feet for general industry. For masonry, such as in overhand bricklaying operations on a supported scaffold, the trigger height can jump to 10 feet. This is because a standard scaffold is 5 feet high, which is below the construction 6 feet minimum trigger height. But when you add a single story of scaffold, the next working surface will be at 10 feet, which triggers you to use proper fall protection.

Trigger height is the vertical distance from a working surface to the next lower working surface – not necessarily the ground. If you are working on an elevated surface 30 feet above the ground, but there is a roof or other surface 7 feet below your working surface, you need fall protection.  Trigger heights refer to the legally required instances when fall protection is required. Common sense, however, dictates that proper fall protection should be used any time a worker is at risk of falling.

From low risk to high risk – the Fall Protection Hierarchy

Once it’s established fall protection is necessary, the next step is determining which type of protection is most appropriate.  Throughout the fall protection industry, professionals refer to a basic structure known as the Fall Protection Hierarchy when considering solutions.

The Fall Protection Hierarchy is best remembered by a simple acronym – E.P.R.A. The first and safest option – the E– is to Eliminate the risk entirely.  It may be possible, through a change in methods or equipment, to eliminate the need for a worker to be exposed to a fall.  Engage fall protection experts for input.

Your next option – the P– is to Prevent access to the fall hazard with a passive physical barrier; guardrails are the most common solution. In overhead bricklaying, for example, guardrails will be the primary fall protection solution as scaffolding grows and work proceeds.  Bricklayers must not only be protected from falling off the back side (opposite the working area) of scaffolding, they must also be protected at the ends.

The mobile nature of overhead bricklaying often requires the use of the next level of protection in the hierarchy, which comes into play when a hazard can’t be physically blocked.  stands for Restraint, using an ABC assembly (see more below) to allow the worker freedom of motion, but tethering him/her to prevent access to the fall hazard.  In restraint applications, the fall hazard itself is not blocked, but the worker is prevented from accessing the fall hazard via a suitable device. A great deal of care must be taken during the assembly of restraints to ensure workers do not inadvertently access a fall hazard throughout the workday. Common restraint solutions are a harness and lanyard, self-retracting device, or a vertical lifeline.

If potentially accessing a fall hazard is unavoidable, you will be at the highest risk level of the Fall Protection Hierarchy – AArrest applications are those in which the worker is at risk of falling over a hazard.  These conditions are common in roofing operations or any time a worker is at the leading edge of a construction project.  Fall arrest applications require specialized equipment designed to withstand not only the stress of a falling worker but, in some cases, contact between the lifeline and damaging work edges.

Back to the ABCs

If your site hazard survey dictates the need for fall restraint or fall arrest, you’ll need to know three more letters – A.B.C.  Every personal fall arrest system (PFAS) is composed of an Anchor, Bodywear, and a Connecting Device.  Anchors can include roof-mounted posts, trailing beam-mounted grabs, wrap-around cinch straps and more.  In masonry, especially during pre-pour operations, the anchor is often the rebar tower itself, provided it is deemed compatible by an onsite competent person. Other anchors commonly used in masonry work include D-ring plates, toggle anchors, and swivel anchors.

Bodywear includes any of the full-body harnesses compatible with fall restraint or fall arrest operations. These can vary from basic to premium, with multiple D-ring options (dorsal, shoulder, side) as work conditions require. Given the abrasive nature of masonry work, harnesses with additional strap protection, such as certain covers made from polyvinyl or certain Cordura™ fabrics, have an extra degree of protection.

A connector is what physically connects the harness to the anchor. Connectors range from simple fixed-length nylon or steel lanyards to single or dual self-retracting devices, 6 to 100 feet in length.  In masonry, a common device is a rebar chain assembly or positioning device. A short length of chain (or nylon) connects a pair of snap hooks, which attach to the side D-rings of a harness. A large rebar hook attached to the chain (or nylon) attaches across a rebar intersection and supports the worker during rebar tying operations.  Connector selection is never a one-size-fits all situation; in many cases, it is a many-fits-one situation.  Local conditions, such as fall clearance, help determine the best connector.

A critical measure

Calculating proper fall clearance is an essential part of creating an effective fall protection system. There are five key factors to consider when calculating fall clearance: free fall distance (the distance a worker will fall with no force acting against the fall), deceleration distance (the distance required by the arresting system to stop the fall), harness stretch, safety factor, and swing falls (other obstructions a worker may impact below the working surface).

Fall clearance is highly variable and, in the case of moveable obstructions, dynamic. Depending on the type of equipment used, fall clearance can range from 6.5 feet to over 19 feet. It is incumbent on safety professionals to fully understand the technical specifications of fall protection equipment to properly calculate fall clearance as there is no single solution to all the potential applications.

Fall protection solutions can be complex. In every instance, however, it’s simple to remember that the first tool to reach should be knowledge. Whether it’s reviewing OSHA regulations, product manuals, calling your supplier’s customer service, or signing up for an in-person competent person class, increasing your knowledge on fall protection safety is the first and most important step in keeping workers at height safe.

Words: Doug Boehm, director of training, Pure Safety Group