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Personal Fall Arrest Systems (PFAS)

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Personal Fall Arrest systems (PFAS) Components and Proper Use

The three components that make up a personal fall arrest system are the anchor point, bodywear (i.e. harness), and the connecting device (i.e. lanyard or fall limiter). Harnesses and connecting devices must be in compliance with national standards, inspected regularly, and properly worn, stored, and maintained. For information regarding personal fall arrest system equipment, see Appendix F of the Personal Protective Equipment Program.

The free fall distance shall be limited to no more than 6 feet, nor shall the person contact a lower level. To avoid contacting the next lower level, determine the fall clearance distance and compare it to the height of the anchor point from the ground or the next lower level. The configuration of the fall protection system chosen must be less than the fall distance (typically the height of the anchor point). The fall clearance distance consists of:

  • Length of the anchor point (if using a strap, etc.);
  • Length of the connecting device;
  • Length of shock-absorber (after deployment);
  • The average height of a worker (estimate 6 feet); and
  • Safety factor (estimate 3 feet).

Anchor Points

Many roofs on university buildings will have a designated anchor point already installed for convenience. Others may have a mobile anchor point that personnel must be trained on prior to use, and some roofs may not provide any fall protection (and temporary systems must be implemented by the personnel accessing it). Available information on fall protection systems per building is provided on the Roof Access Chart.

The hardware of the connecting device (i.e. lanyard) must be connected to the hardware of the anchor point unless specifically designed to "tie-back." Regular lanyards used in this manner have often failed, resulting in injury or death.

singular roof anchor


Full body harnesses are approved for fall arrest, positioning, confined space rescue, and with ladder climbing devices. The combined body weight and tool weight of the person wearing the harness must be less than 310 lbs. The back D-ring is the only connection point that can be used for fall arrest. Other D-rings on the harness are for confined space rescue (shoulder D-rings), ladder climbing devices (front, chest D-ring), or positioning (side, hip D-rings). The webbing used on some harnesses are burn resistant (ex. welding), chemical resistant, or flame-retardant (ex. arc-flash protective). Choose a harness that is suitable for the work to be performed and the materials to be used.

yellow crossarm

Connecting Device

Connecting devices are attached to the back D-ring of the harness and to the hardware of the anchor point. They must be inspected prior to use by the user and at least annually by a competent person. There are two primary types of connecting devices:

  • Lanyards are typically 6 feet in length and must be used with a shock-absorber when used for fall arrest. The shock-absorber may expand up to three and a half feet during deployment. They may be made of steel wire, webbing, or rope. Snap hooks must have a self-locking gate.
  • Fall limiters are self-retracting lifelines (SRL) that operate in a similar manner as a seatbelt. Falls are limited to two feet or less. The shock-absorber may expand up to 2-and-a-half feet during deployment. Because fall limiters restrict the free fall distance to two feet and the shock-absorber expansion to two and a half feet, they are considered more protective and therefore a better choice.

Falls and Rescue

Personnel working at heights where personal fall arrest systems are implemented must have a rescue plan. The rescue plan will specify how to summon emergency services, what responses can be taken by personnel in the area, and what responses should not be taken by personnel in the area. If rescue equipment, such as controlled descent devices or rescue poles are provided, personnel must be trained by their department on how to use it.

The buddy system (i.e. at least two persons on-site) must be implemented for fall protection options which could leave a person "stranded" or where a fall may not be detected for some time and emergency services delayed, such as when personal fall arrest systems are worn, an aerial lift is used, or warning lines/controlled access zones are used. Other options, such as the use of a safety monitor, require at least two people to implement.

For personnel wearing harnesses, remember to pull your knees up into a sitting position to avoid the effects of suspension trauma. If a self-rescue is possible, proceed with caution. Otherwise, lighten the load by removing tool belts or equipment and wait for emergency services to respond.

All components of the personal fall arrest system must be removed from service once it has experienced a shock-load from a fall.

Contact Information

Robin McCall-Miller, Occupational Safety Program Manager