There’s More to Fall Protection than the Lanyard
Kids enjoy jumping from “high” locations. You probably jumped off of playground equipment, tree limbs, or small hills — and probably walked away with the scrapes and bruises that demonstrate the hazards.
As adults, falling can be frightening. We rarely fall deliberately, and the surfaces that break our falls these days are less forgiving than grassy fields and playground surfaces. Our bones and joints are less forgiving, too. Plus, when you fall from just six feet, your body will hit the ground at 13 miles per hour.
Falls are a major concern for safety professionals, because workers often underestimate the inherent danger and elevated work surfaces are common in construction and maintenance projects. Although fall-protection strategies are a critical component of safety programs, workers don’t always understand the correct use of personal protective equipment such as shock-absorbing lanyards, which creates a false sense of security and the very real prospect of danger.
How far will you fall?
The potential distance for a fall is the key consideration in identifying proper fall protection. You can wear the highest-quality lanyard and tie it securely to a safe anchorage point, but if you haven’t properly computed the fall distance, you may hit the floor before that lanyard has the opportunity to do its job. You might also find yourself dangling in an uncomfortable and potentially dangerous position while your co-workers struggle to rescue you.
The physics involved in fall distance can be complex, but the math needed on a worksite is very simple. The fall distance is determined by measuring from the anchorage point, adding the length to which the lanyard will stretch out, plus the length of the body.
Suppose a six-foot-tall worker is using a six-foot shock-absorbing lanyard that has been attached to a full-body harness. The lanyard’s specifications note that the maximum elongation of the shock absorber is three and one-half feet. If we add the worker’s height to the length of the lanyard, and then add in the maximum elongation, we arrive at a total length of 15 1/2 feet. However, that’s not the potential fall distance.
We have to take another step. Suppose the harness hasn’t been fitted properly, or the worker loosens the leg straps to make them more comfortable? Suppose he’s really 6’3” tall? Suppose he has overestimated the height of his work area? Factors such as these are why we add in a safety factor of three feet, bringing the total safe fall clearance distance in this example to 18 1/2 feet. In other words, the worker must attach his fall protection device to an anchorage at least 18 1/2 feet above the floor or the equipment that’s below the place where he’ll be working.
If the available clearance is less than that, he’ll need to consider the use of other safety equipment, such as self-retracting lifelines (SRLs).
The general guidance is to tie off to an anchorage point that’s as far above the worker’s head as is practical. That reduces the chances that the worker will strike the ground or objects underneath the work area. It will also limit the potential fall distance and the forces his body will experience in a fall. It may even keep him close enough to his work area to allow for self-rescue if he falls.
Finding a safe anchorage
The highest-quality personal protective equipment becomes worthless when a worker uses it improperly, and that holds true for personal fall-protection equipment. A worker can use the best lanyard, but hooking it to an unsafe anchorage point will provide a false sense of security.
Even if a potential anchorage point is part of the structure or made of a strong material such as steel doesn’t ensure that it provides a safe place to attach a fall protection device. The standard says that an employer may establish an anchor point of a tolerance that is more or less than 5,000 pounds as long as the entire fall protection system maintains a safety factor of two per its anticipated load, and is designed, installed and used under the supervision of a qualified person. The standard also requires employers to establish the 5,000-pound rating for anchorage if it will not be used under the supervision of a qualified person. OSHA describes a “qualified person” as one who, by possession of a recognized degree, certificate or professional standing, or by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work or the project.
Rather than allow workers to choose their own anchorage points, safety professionals and the qualified person should identify appropriate anchorage points before work begins. They need to consider the highest possible tie-off locations, where staff will be working in relation to the anchorage points, and then identify and mark safe anchorage points. That way, workers won’t have to guess where they should tie off, and they’re less likely to tie off to a site that can’t safely support them. Consulting with the architect and structural engineer can help. Remember, proper planning prevents poor safety performance.
In addition to considering structures, thought should be given to fall protection when lift equipment is being used. Safety professionals need to identify appropriate options for fall protection in these situations and consult with the lift manufacturers.
Consider more than vertical distance
We generally focus on the height involved in the task, but it’s just as important to look at the horizontal aspects. For example, if a worker falls, his body may swing back and forth in a pendulum effect. He could easily swing into other workers, nearby structures, or even equipment that is moving or dangerously hot.
For example, a worker who is going to perform tasks at multiple locations on a roof or open floor area will select a retractable lanyard to allow freedom of movement. He may believe that once the lanyard has been secured, he can move anywhere in that range with complete safety. But that isn’t the case, because if he stretches the lanyard out horizontally and falls over the edge, he may fall the full distance before the safety clutches kick in. He could hit the ground, or could find himself swinging. That’s why most manufacturers recommend that workers use no more than a 30 percent offset from the anchorage point to the body position.
Another consideration when choosing a tie-off location is hazards that may be located within the potential fall area. If energized equipment, moving machinery such as exposed drive shafts, or other potentially hazardous objects are in the immediate area, the fall distance must ensure that the fall will be stopped before the worker comes in contact them. Think about impalement hazards, too. Workers may neglect to place rebar caps on bars sticking out of forms, so roofers or others working above the forms may be at risk for being impaled upon the exposed portions of the rebar.
Fall protection in warm weather
Humans want to feel more comfortable, and that can lead to increased hazards on a worksite. When temperatures and humidity increase, workers may begin to resent their fall-protection harnesses. It’s not unusual for them to respond by loosening the straps, but doing so dramatically reduces the protection the equipment provides. If one set of straps is loosened, the others (usually the leg straps) will end up providing most of the support in a fall, which could cause an injury.
If hot weather (or hot work) conditions create these issues on a jobsite, a safety professional can recommend several solutions, such as harnesses made with material that wicks perspiration away from the body (similar to the apparel worn by athletes). Some harnesses allow for optional padding that can improve comfort. Workers may be tempted to remove their shirts and use their harnesses on the bare skin, but that can cause more pain in the event of a fall.
Also consider issuing clip-on water bottles with drinking tubes to workers who use fall protection in hot areas. They may not have easy access to water sources, putting them at greater risk for dehydration and heat illnesses.
When a worker stumbles or slips, and his fall protection arrests the fall, he’s safe, right? Not necessarily. A worker suspended in a harness must be brought down within five minutes before he can begin to lose circulation in his legs and even develop blood clots. If the pressure is relieved too quickly, the sudden rush of blood through the circulatory system can lead to other problems.
Counting on local emergency responders to bring him down? They may not be able to reach your location within that time frame, so it’s critical to develop your own rescue plan for all of the elevated aspects of your project before work begins. The plan should address how you’ll recover workers who are conscious, and what type of equipment on the site – such as vertical lifts, manlifts, or ladders – are available.
It should also include training for employees in the area, because well-intentioned efforts to help may actually complicate the situation. A worker who reaches down to grab the lanyard and pull his co-worker to safety can easily injure himself, turning one elevated rescue into two. If the suspended worker is unconscious or has significant injuries, pulling him up may worsen his condition and make it more difficult for the rescue team to help.
Training provides the best protection
Lanyards and other devices can help protect workers from the hazards associated with falls, but it’s all too easy for workers using those devices (and the supervisors responsible for them) to become complacent about safety.
Companies must place a high priority on training everyone involved. In addition to properly identifying anchorage points and explaining the use of equipment, training should ensure that everyone knows what to do when a mishap occurs. That knowledge makes the difference between having only a perception of safety and achieving effective protection.