Personal fall arrest system

A personal fall arrest system is a chain, with a fixed anchorage at one end and the worker's harness at the other. OSHA's definition names the anchorage first, and the list below follows the chain outward from it.

• Anchorage. Section 1926.500(b) defines it as “a secure point of attachment for lifelines, lanyards or deceleration devices.” Everything else hangs from it.
• Lifeline, lanyard or deceleration device. A lifeline is a flexible line that connects the other components of the system to the anchorage. The definition lists a lanyard and a deceleration device as parts a system may include.
• Connectors. Named in the definition as one of the three parts every system has; they join the other parts to one another.
• Body harness. The part the worker wears. Section 1926.502(d) places its attachment point “in the center of the wearer's back near shoulder level,” or above the wearer's head.

The definition still names a body belt beside the body harness, and then rules it out: as of January 1, 1998, the use of a body belt for fall arrest is prohibited, and section 1926.502(d) repeats that “body belts are not acceptable as part of a personal fall arrest system.”

Section 1926.502(d) turns the parts into a set of performance rules. Stopping a fall, a system must limit the maximum arresting force on an employee to 1,800 pounds when used with a body harness. It must be rigged so that an employee can “neither free fall more than 6 feet (1.8 m), nor contact any lower level.” Both conditions apply at once, so the rigging has to account for the distance to the nearest lower level as well as the length of the free fall.

The anchorage carries its own figure. Anchorages used for personal fall arrest equipment must be independent of any anchorage used to support or suspend platforms, and capable of supporting at least 5,000 pounds per employee attached, or else meet the design alternative the rule sets out beside that figure.

The last rule in the set is about condition. OSHA requires personal fall arrest systems to be “inspected prior to each use for wear, damage and other deterioration,” and defective components to be removed from service. The rule attaches the inspection to each use, not to a calendar.

A personal fall arrest system is one of the three choices 1926.501 accepts at a 6-foot edge, beside guardrail systems and safety net systems. How the rule applies to a particular job is a question for OSHA. Equipment that steadies a ladder, such as a ladder standoff, is not among the parts the definition lists, and who walks on a roof during a cleaning is a question with its own answer.