Personal Fall Arrest Systems (PFAS)
Equipment used for personal fall arrest must be inspected by the user prior to each use and by a competent person at least annually. The annual inspection should be documented, either on the tag provided on the equipment, the documentation provided by the manufacturer, or a separate form kept on file. A general rule of thumb when inspecting safety equipment is "when in doubt, throw it out". When inspecting the harness and connecting devices, look for the following:
- "Software" (webbing material)
- Frayed edges
- Broken fibers
- Pulled stitches
- Chemical damage
- Burn spots
- Signs that the equipment has received a load
- "Hardware" (metal components)
- Rough/sharp edges (burrs)
- Bent parts
- Working properly
Proper donning and fit of the harness is important. A harness that does not fit snuggly can result in injury during a fall, such as abrasions or contusions. A harness that has not been properly donned can result in the inability to achieve a sitting position while awaiting rescue. This is critical in preventing suspension trauma/orthostatic intolerance. When donning the PFAS, follow these guidelines:
- Put the harness on similarly to how you would put on a vest.
- Next, position the sub-pelvic strap below the buttocks.
- Ensure the D-ring is positioned between the shoulder blades.
- Connect the leg straps so that they are snug, but not too tight.
- Connect the chest strap so that it is low on the chest.
- Adjust the length of the harness (i.e. shoulder straps) so that it fits snuggly when standing up straight.
- Tuck all loose straps into elastic loop-keepers.
- Attach connecting device to the back D-ring between the shoulder blades.
If the harness has been donned properly, it should function as intended in the event of a fall. The sub-pelvic strap will be in position so that the knees can be bent and brought up into a sitting position. This will relieve pressure on the lower extremities. The back D-ring should not move past the nape of the neck and the chest strap should not move up to the neck - if they do, the harness was not adjusted properly or was too loose.
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). There are basic requirements and guidelines for each component.
Anchor points and the structure supporting the system must be capable of supporting 5,000 pounds of force per attached person. Steel I-beams, concrete columns, large rebar, and steel columns are common examples of structures which can be used for anchor points. If these types of structures are not available in the work area, an "engineered system" may be used. The anchor point for an engineered system must be capable of supporting at least two times the maximum allowable force (i.e. 1,800 lbs.), or 3,600 pounds. This system must be determined by a "qualified person". When a shock-absorbing lanyard is used, the maximum allowable force is greatly reduced to around 900 pounds (for a 200 pound person), resulting in an anchor point that must support at least (2 x 900) 1,800 pounds.
Many roofs on campus buildings (see Roof Access Chart) will have a designated anchor point already installed for convenience. Information on permanent and mobile anchor points is available here. The hardware of the connecting device (i.e. lanyard) must be connected to the hardware of the anchor point.
Where beams will be used as an anchor point, a cross-arm strap may be necessary. Cross-arm straps must also be inspected prior to use and annually. Softeners may be necessary to protect the cross-arm strap on beams that are rough or have sharp edges which can tear or cut into the strap. The hardware of the connecting device (i.e. lanyard) must be connected to the hardware of the cross-arm strap.
Only specially designed lanyards may be used to wrap around a column or beam and connect back to the lanyard webbing (i.e. "tie-back"). Regular lanyards used in this manner have often failed, resulting in injury or death.
The full body harness is the only acceptable type of bodywear for personal fall arrest. As of January 1, 1998, body belts are approved only for "positioning" and may not be used for fall arrest. Full body harnesses are approved for fall arrest, positioning, confined space rescue, and with ladder climbing devices. 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.
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 six 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 retractable life lines that operate in a similar manner as a seatbelt. Falls are limited to two feet or less. The shock-absorber may expand up to two 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.
Personnel working at heights 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.
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 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.