If workers will be exposed to fall hazards that you can't eliminate, you'll need to prevent falls from occurring or ensure that if workers do fall, they aren't injured. A fall-protection system is designed to prevent or arrest falls.
We know that eliminating all fall hazards on the construction site is impossible because they are inherent in the nature of construction work. However, it is possible to mitigate (to become less harmful) many hazards for tasks that must be performed at elevation. To begin the process, identify each worksite fall hazard and analyze each one for the following variables that help to determine the risk that a hazard presents:
Probability – the likelihood of a fall accident if the employee is exposed to a hazard; and
Severity – the magnitude of the injury ranging from no injury to fatal injury;
You can use a risk matrix to help you determine the degree of risk different worksite task might present. Know that will help you determine appropriate fall-protection systems for your worksite.
Many factors affect the probability of a fall accident and the severity of injury. Click the buttons to see a partial list of the most common factors affecting probability and severity, and the questions you might ask in your analysis of the factors.
Scope – the number of employees performing a task
Frequency – how frequently the task will be performed
Rapidity – how quickly an employee must perform a task
Duration – how long it takes an employee to perform a task
Elevation – the height at which an employee will perform a task
Orientation – the body part(s) that will likely strike a lower surface
Equipment – exposure to sharp points, moving parts, and hazardous energy
Materials – exposure to toxic chemicals, substances, and materials
Exertion – the demand on an employee to exert excessive force (lifting, lowering, pushing, or pulling)
Physical environment – workplace temperature, atmospheres, humidity, illumination, and noise
Psychosocial environment – the psychological stress that causes distraction
Response – the promptness of rescue and quality of treatment of an injury
Keep the following in mind:
What is the fall distance from the walking/working surface to the next lower level?
How many workers are exposed to the hazard?
What tasks and work areas are associated with the hazard?
How will the workers move - horizontally, vertically, or in both directions - to do their tasks?
Are secure anchorages available or can they be easily installed near the hazard?
Are there other hazards near the work area, such as overhead power lines?
How will workers be promptly rescued if they are suspended in a personal fall-arrest system?
For more information on determining risk, see OSHAcademy Course 706, Job Hazard Analysis.
2. What are the two primary variables that help determine the risk that a hazard presents?
a. Duration and scope
b. Probability and Severity
c. Elevation and Exertion
d. Frequency and physical environment
A personal fall-arrest system consists of an anchorage, connectors, and a full-body harness that work together to stop a fall and to minimize the arrest force. Other parts of the system may include a lanyard, a deceleration device, and a lifeline.
Ensure that personal fall arrest systems will, when stopping a fall:
Limit maximum arresting force to 1,800 pounds.
Be rigged such that an employee can neither free-fall more than 6 feet nor contact any lower level.
Bring an employee to a complete stop and limit maximum deceleration distance to 3½ feet.
Have sufficient strength to withstand twice the potential impact energy of a worker free falling a distance of 6 feet, or the free fall distance permitted by the system, whichever is less.
Remove systems and components from service immediately if they have been subjected to fall impact, until inspected by a competent person and deemed undamaged and suitable for use.
Promptly rescue employees in the event of a fall, or assure that they are able to rescue themselves.
Inspect systems before each use for wear, damage, and other deterioration, and remove defective components from service.
Do not attach fall arrest systems to guardrail systems or hoists.
Rig fall arrest systems to allow movement of the worker only as far as the edge of the walking/working surface, when used at hoist areas.
3. Workers wearing a personal fall-arrest system should be rigged so that an employee _____.
a. can not free-fall more than 6 feet
b. can only fall if the system fails
c. can fall up to 5 feet
d. can free fall 4 feet over an edge
Body harnesses are designed to minimize stress forces on an employee's body in the event of a fall, while providing sufficient freedom of movement to allow work to be performed. Harnesses, and components must be used only for employee protection (as part of a personal fall arrest system) and not to hoist materials. Click on the button to see some important requirements and practices when choosing a harness.
Keep the following in mind:
The harness must be made from synthetic fibers.
The harness must fit the user. It should be comfortable and easy to adjust.
According to ANSI/ASSP Z359.2, Minimum Requirements for a Comprehensive Managed Fall Protection Program, the harness must have an attachment point, usually a D-ring, in the center of the back at about shoulder level. A D-ring may also be used in the front of the harness. However, connection at the front D-ring is limited to systems that restrict free fall distance to 2 ft or less and limit the maximum fall arrest loads on the front D-ring to 900 lbs of force or less. The D-ring should be large enough to easily accept a lanyard snap hook.
Chest straps should be easy to adjust and strong enough to withstand a fall without breaking.
Use only industrial full-body harnesses (not recreational climbing harnesses).
The harness must be safe and reliable. It should meet ANSI and CSA standards and the manufacturer should have ISO 9001 certification, which shows the manufacturer meets international standards for product design, development, production, installation, and service.
Body belt used as a positioning device.
A body belt is a strap with means both for securing about the waist and for attaching to other components such as a lanyard used with a positioning system while working on a vertical surface, or a travel restraint system when on a horizontal work surface.
Body belts are not acceptable as part of a personal fall arrest system because they impose a danger of internal injuries when stopping a fall. Body belts may only be used as part of a vertical positioning system or a horizontal restraint system.
4. What must a body harness be made of?
a. Organic or synthetic fibers
b. Natural fibers
c. Synthetic fibers
d. Synthetic or natural fibers
An anchorage system is a secure point of attachment for lifelines, lanyards, or deceleration devices. How can you be sure that an anchorage is secure?
An anchorage for a personal fall-arrest system must support at least 5,000 pounds. Anchorages that can't support 5,000 pounds must be designed and installed under the supervision of a qualified person and must be able to maintain a safety factor of at least two - twice the impact force of a worker free-falling 6 feet. If you don't know how much weight an anchorage will support, have a qualified person check it before you trust your life to it.
Anchorage strength is critical, but is not the only factor to consider. Click on the button to see other factors that are important.
Anchorage connector: Unless an existing anchorage has been designed to accept a lanyard or lifeline, you'll need to attach an anchorage connector - a device that provides a secure attachment point. Examples include tie-off adapters, hook anchors, beam connectors, and beam trolleys. Be sure that the connector is compatible with the lanyard or lifeline and appropriate for the work task.
Attachment point: The anchorage can be used only as the attachment point for a personal fall-arrest system; it can't be used to support or suspend platforms.
Location: The anchorage should be located directly above the worker, if possible, to reduce the chance of a swing fall.
Fall distance: Because a personal fall-arrest system doesn't prevent a fall, the anchorage must be high enough above a worker to ensure that the arrest system, and not the next lower level, stops the fall.
Connectors: An anchorage, a lanyard, and a body harness are not useful until they're linked together. Connectors do the linking; they make the anchorage, the lanyard, and the harness a complete system. Connectors include carabiners, snap hooks, and D-rings.
Carabiner: This high-tensile alloy steel connector has a locking gate and is used mostly in specialized work such as window cleaning and high-angle rescue. Carabiners must have a minimum tensile strength of 5,000 pounds.
Snap hook: A hook-shaped member with a keeper that opens to receive a connecting component and automatically closes when released. Snap hooks are typically spliced or sewn into lanyards and self-retracting lifelines. Snap hooks must be high-tensile alloy steel and have a minimum tensile strength of 5,000 pounds. Use only locking snap hooks with personal fall-arrest systems; locking snap hooks have self-locking keepers that won't open until they're unlocked.
D-ring: D-rings are the attachment points sewn into a full-body harness. D-rings must have a minimum tensile strength of 5,000 pounds.
The full-body harness: The full-body harness has straps that distribute the impact of a fall over the thighs, waist, chest, shoulders, and pelvis. Full-body harnesses come in different styles, many of which are light and comfortable.
5. How many pounds must an anchorage for a personal fall-arrest system support?
a. At least 2,000 pounds
b. More than 3,000 pounds
c. Up to 4,000 pounds
d. At least 5,000 pounds
A lanyard is a specially designed flexible line that has a snap hook at each end. One snap hook connects to the body harness and the other connects to an anchorage or a lifeline. Lanyards must have a
minimum breaking strength of 5,000 pounds. They come in a variety of designs, including self-retracting types that make moving easier and shock-absorbing types that reduce fall-arrest forces.
Don't combine lanyards to increase length or knot them to make them shorter.
Deceleration devices protect workers from the impact of a fall and include shock-absorbing lanyards, self-retracting lifelines or lanyards, and rope grabs.
A shock absorber reduces the impact on a worker during fall arrest by extending up to 3.5 feet to absorb the arrest force. OSHA rules limit the arrest force to 1,800 pounds but a shock-absorbing lanyard
can reduce the force even more - to about 900 pounds.
Because a shock-absorbing lanyard extends up to 3.5 feet, it's critical that the lanyard stops the worker before the next lower level. Allow about 20 vertical feet between the worker's anchorage point
and the level below the working surface. Always estimate the total distance of a possible fall before using a shock-absorbing lanyard.
Self-retracting lanyards and lifelines offer more freedom to move than shock-absorbing lanyards. Each has a drum-wound line that unwinds and retracts as the worker moves. If the worker falls, the drum immediately locks, which reduces free-fall distance to about 2 feet - if the anchorage point is directly above the worker. Some self-retracting lanyards will reduce free-fall distance to less than one foot. Self-retracting lanyards are available in lengths up to 20 feet. Self-retracting lifelines, which offer more freedom, are available in lengths up to 250 feet.
Self-retracting lanyards and lifelines that limit free-fall distance to 2 feet or less must be able to hold at least 3,000 pounds with the lanyard (or lifeline) fully extended.
Self-retracting lanyards that don't limit free-fall distance to 2 feet must be able to hold at least 5,000 pounds with the lanyard (or lifeline) fully extended.
If you use a self-retracting lanyard or lifeline, work below the anchorage to avoid a swing fall. The farther you move away from the anchorage, the farther you will fall and the greater your risk of swinging back into a hard object. Swing falls are hazardous because you can hit an object or a lower level during the pendulum motion.
7. A self-retracting lanyard or lifeline reduces the free-fall distance to about 2 feet if _____.
a. the worker has not extended the lanyard
b. the anchorage point is directly above the worker
c. the work is on a low-slope roof
d. the anchorage attached at shoulder level
OSHAcademy founder, Steve Geigle, is 300 ft up inside a wind turbine. He used a rope grab while climbing the ladder.
A rope grab serves as a tie-off point that allows a worker to move up a vertical lifeline. It automatically engages and locks in place on the lifeline to prevent the worker from falling. When using a rope grab, keep the following in mind:
Inspect the rope grab before use for distortion, rust, sharp edges and jammed moving parts
Make sure the rope grab is compatible with the lifeline (the right rope size or type)
Attach the rope grab correctly to the lifeline (arrow points up)
After attaching the rope grab to the lifeline, give it a firm tug to verify it engages
Keep the distance on the lanyard between the rope grab and the body harness as short as possible
Keep the rope grab as high as possible above the d-ring on the lifeline to shorten the free-fall distance
Do not grab the device during a fall
Only one person at a time may use the same vertical lifeline
If the rope grab arrests a fall, inspect and recertify it for use
8. After attaching the rope grab to the lifeline, what should you do to test it?
a. Give the rope grab a firm downward tug
b. Grab the device to test its ability to hold
c. Ensure the arrow is pointing down on the device
d. Keep the rope grab at or below the harness d-ring
A lifeline is a cable or rope that connects to a body harness, lanyard, or deceleration device, and at least one anchorage. There are two types of lifelines. (Vertical and Horizontal)
Vertical lifeline: A vertical lifeline is attached to an overhead anchorage and must be connected directly to a worker's full-body harness, lanyard, retractable device, or rope grab; it must have a minimum breaking strength of 5,000 pounds.
When a worker needs to move horizontally, however; a vertical lifeline can be hazardous due to the potential for a swing fall - the pendulum motion that results when the worker swings back under the anchor point. A swing fall increases a worker's risk of striking an object or a lower level during the pendulum motion.
Horizontal lifeline: Unlike a vertical lifeline, the horizontal lifeline stretches between two anchorages.
When you connect a lanyard or rope grab to the horizontal lifeline, you can move about freely, thus reducing the risk of a swing fall. However, horizontal lifelines are subject to much greater loads than vertical lifelines.
If they're not installed correctly, horizontal lifelines can fail at the anchorage points. For this reason, horizontal lifelines must be designed, installed, and used under the supervision of a qualified person.
Example: When the sag angle is 15 degrees, the force on the lifeline and anchorages subjected to a load is about 2:1. However, if you decrease the sag angle to 5 degrees, the force increases to about 6:1. To reduce loads on a horizontal lifeline, increase the sag angle or connect to the lifeline with a shock-absorbing lanyard.
9. What advantage does a horizontal lifeline have over a vertical lifeline?
a. Arrest forces are increased during a fall
b. You can easily move horizontally as well as vertically
c. There is a reduced risk of a swing fall
d. A qualified person must supervise its use
Five roofing-company workers had been removing cedar shingles and replacing them with plywood sheeting and composition roofing at a two-story residence.
Four of the crew went up on the roof, the victim remained on the ground to push plywood sheets up an extension ladder to crew members on the roof. When all the plywood sheets were on the roof, the victim climbed the ladder and got on the roof. Then he bent down near the top of the ladder to nail down shingles.
Another worker on the roof heard a loud noise, rushed over to the ladder, and discovered that the victim had fallen to the ground. The workers climbed down to assist the victim and the supervisor called 911. The workers administered first aid and immobilized the victim's neck. Unfortunately, the victim died in the hospital of traumatic head injuries later that day.
The victim, who was hired the day of the accident, had no ladder safety or fall-protection training (the most common root cause for roofing accidents). Although the workers at the site had fall-protection equipment, none of the workers were using it according to the manufacturer's instructions. The roof edge was more than 17 feet above the ground.
The safety management system root causes for this fatal accident included:
a lack of safety training in fall protection and ladder safety;
a lack of enforcement of safety rules; and
inadequate safety supervision.
11. What is the most common root cause of roofing construction accidents?
a. Lack of enforcement of safety rules
b. Inadequate safety training
c. Poor worker supervision
d. Lack of employee involvement in safety
Check your Work
Click the button to get your quiz results. You will receive a message if you did not answer all of the questions. Correct missed questions and return to this module to recheck your answers.