This infographic, titled “The A, B, Cs and 1, 2, 3s of Fall Protection,” explains the parts of a personal fall arrest system (PFAS), the personal protective equipment (PPE) often used to protect employees who work at heights. It also demonstrates how to calculate your fall distance, which is important because that number allows you to determine whether the personal fall arrest system you are using is appropriate for your situation.

The key components of a personal fall arrest system are (A) Anchorage, (B) Body Support, and (C) Connectors.

The anchorage is a secure point that people wearing personal fall arrest systems are attached to. It is also referred to as a tie-off point and it is something that can withstand a lot of force such as a wall or I-beam. An anchorage point should be able to withstand 5000 pounds of static force because when a person falls off a ledge, his or her weight and the force of the fall create significant strain.

The body support is the harness that fastens around the person wearing this protective gear. It has straps that go around the person’s chest, legs, back, and shoulders. These straps are called webbing and are made from a synthetic material. They fasten with buckles, which come in three main styles: quick connect buckles, mating buckles, and grommet leg attachments. Then a D ring—a metal ring on the back of the harness between the shoulders—is where the worker is connected to the anchorage point with the connector.

Connectors come in two styles: shock-absorbing lanyards and self-retracting lanyards. The former stretches when a person falls to absorb the shock. These lanyards are usually six feet long. The latter style consists of a line wound around a device that allows the line to uncoil and recoil so the person can move around. If a fall occurs, the line locks so he or she can’t fall any further.

In the case of shock-absorbing lanyards, it might seem like the fall distance should be six feet if the lanyard itself is six feet. This infographic addresses why that is not the case and how to calculate the actual fall distance. To do so, you add the length of the lanyard (six feet) to the deceleration distance, which is the amount the lanyard stretches (3.5 feet). Then you add the height of the worker to that number (in this example, let’s say six feet). Finally, you add a safety factor (two feet). This comes out to 17.5 feet for a six-foot tall worker attached to a standard six-foot lanyard. This means that for a person to clear the nearest obstruction, there needs to be at least 17.5 feet between where the fall occurs and the ground (or lower level).

Personal fall arrest systems are one of several ways to protect employees from falls. Businesses can also use guardrails or nets to protect employees from falls. Regardless of which method or combination of methods is used, businesses should make sure they comply with OSHA regulations for when fall protection is required. In construction, whenever people are working at heights above six feet, fall prevention and protection methods must be used.

Everything you want to know about Fall Protection