The fall arrest system did its job. The anchorage held, the connecting device caught the fall, and the worker is hanging in a full body harness below the working surface. Someone calls 9-1-1, because that is what you do in an emergency, and the crew waits. The fall has been arrested, but the emergency is not over, and how quickly that worker gets down now matters most.
Why the wait is dangerous is covered in our article on suspension trauma. In short, a worker hanging motionless in a harness can become faint and lose consciousness, sometimes within minutes, and there is no reliable way to predict who or when. This article is about the other side of that problem: how the worker actually comes down.
What the law requires
In the United States, the duty sits with the employer. In construction, the Occupational Safety and Health Administration (OSHA) rule at 29 CFR 1926.502(d)(20) requires the employer to provide for prompt rescue of employees in the event of a fall, or assure that employees are able to rescue themselves. In general industry, 29 CFR 1910.140(c)(21) requires the employer to provide for prompt rescue of each employee in the event of a fall. Rules outside the United States differ, so check the ones that apply where you work.
OSHA has explained what prompt means. In a 2003 interpretation of the construction rule, it said rescue must happen quickly, in time to prevent serious injury to the worker, and that to the extent feasible a reliable system must be in place to make sure rescue will be prompt. The same letter said the construction rule does not require a written rescue plan or a preplanning event. In a 2004 interpretation, OSHA said its standards set no specific maximum time a worker may remain suspended after a fall, though other requirements can create one in some situations. Its example was the electric power standard, which requires workers exposed to electric shock at fixed work locations to be reachable by trained persons within four minutes, a figure OSHA noted was not intended as an absolute time limit.
Showing that a reliable system is in place is hard without having worked out who performs the rescue, with what equipment, from which anchorage, and how fast. That is a plan whether or not it is on paper. Our recommendation is to write it down, because a written plan is easier to train on, practice, and review.
Why the phone is not the plan
There is a saying in the trade: 9-1-1 is not a rescue plan. Emergency services should always be called, but that call cannot be the whole plan. Outside responders have to be dispatched, find the worker, reach someone hanging at height, and bring them down safely, and many are not equipped for a rescue at height. OSHA’s 2003 letter notes that circumstances vary widely between worksites and that feasible options in remote locations may be more limited. Outside help can only be counted on when it has been confirmed in advance to reach the site and complete the rescue promptly.
What the Z359 standards add
The ANSI/ASSP Z359 Fall Protection Code, the family of American National Standards for fall protection published by the American Society of Safety Professionals, builds rescue into both the equipment and the plan. The full body harness standard, ANSI/ASSP Z359.11-2021, says the harness instructions must require the user to have a rescue plan and the means at hand to implement it when the harness is used for fall arrest, so the requirement travels with the harness. The rescue equipment standard, ANSI/ASSP Z359.4-2013 (R2022), requires the people performing a rescue to be equipped with a rescue system identified by an established rescue plan, prepared by a competent person knowledgeable about the rescue site conditions, the rescue application, and the associated hazards.
Z359.4 covers equipment for pre-planned self-rescue and assisted rescue of one or two people. Its requirements do not address rope access rescue techniques used by certified rescue technicians, and its foreword notes that a rescue plan may call for methods outside the standard, such as technical rope rescue, when they are reasonable, feasible, and estimated to be the most effective method. Either way, the standard assumes the rescue is planned before it is needed.
Self-rescue, assisted rescue, and outside help
OSHA’s construction rule allows for employees who are able to rescue themselves, and Z359.4 covers equipment for both self-rescue and assisted rescue. In practice, self-rescue is hard to count on. As Rupert Noton and J. Nigel Ellis write in their book Fall Protection Engineering, self-rescue can rarely be assured, so the employer must provide for assisted rescue. A fallen worker may be injured, disoriented, or unconscious, and a plan that depends on them rescuing themselves fails in exactly the cases that matter most.
Assisted rescue is the core of most plans: a trained rescuer uses a rescue system to raise or lower the fallen worker. One option is a self-retracting lanyard with integral rescue capability (SRL-R), which ANSI/ASSP Z359.14-2021 defines as a self-retracting lanyard with an integral means for assisted rescue by raising or lowering the rescue subject; some SRL-Rs may instead feature controlled descent of the fallen user.
We recommend a trained, equipped crew on site, because they are already there when the fall happens. An outside rescue service can be part of the plan, but only if its capability, availability, site access, and ability to deliver a prompt rescue have been confirmed in advance. What matters is a verified arrangement, not an assumption that help will arrive.
How fast does it need to be?
As fast as it can safely be done. People vary widely in how long they tolerate a still suspension, and a National Institute for Occupational Safety and Health (NIOSH) study of 40 people with construction experience hanging motionless in full body harnesses shows how wide that range is. Each test stopped at medical warning signs, at the subject’s request, or at 60 minutes, and on the back D-ring, suspension times ranged from 5 to 56 minutes. Z359.11 adds a number that is sometimes misread: it requires a full body harness to support the test torso for five minutes after a test fall. That is a test requirement, not a safe suspension time. Plan for the rescue to start as soon as the fall happens and to be measured in minutes.
What a real rescue plan includes
Engineering out the fall hazard comes first. Where a fall hazard remains and fall arrest is in use, a workable rescue plan is specific to the site and the task, and it settles these things before work starts:
- Who performs the rescue: trained people on site, a verified outside rescue service, or both. Whoever it is needs training on the rescue procedures and equipment, and should be able to show they can carry out the rescue, not just describe it.
- What equipment they use: the rescue system the plan identifies, readily available at the work location. Under Z359.4, the competent person identifies the required capacity of that equipment in the plan.
- Where it anchors: under Z359.4, an anchorage used only for rescue must sustain at least 3,100 pounds static, or meet a 5:1 safety factor when designed, installed, and used under the supervision of a qualified person. The standard notes that a 3,100-pound rescue anchorage is not intended for fall arrest and that an anchorage used for both must meet the greater load requirement, and a rescuer exposed to a fall hazard needs an anchorage suitable for fall arrest.
- How the fall changes the setup: a fall changes where the load sits and how the system hangs, and the plan has to account for that. A rescue anchorage above the fallen worker and the rescuer makes rigging easier and limits swing.
- How the worker comes down: how the rescuer reaches and connects to a worker who may not be able to help, how the worker’s weight is transferred from the fall arrest system to the rescue system, and the route and safe landing spot for the raise or lower.
- How the call goes out: emergency services, and any outside rescue service the plan relies on, are called at the start, in parallel with the rescue.
- When it is practiced: before the job starts and again whenever the site, the task, or the crew changes, so the rescue can be carried out quickly and safely.
Once the worker is down
Call emergency services if they are not already on the way, and follow standard first aid and cardiopulmonary resuscitation (CPR) training and the dispatcher’s instructions until responders arrive. Every rescued worker should be evaluated by a medical professional, and responders should be told the worker was suspended. Older advice to keep a rescued worker upright is not supported by current medical guidance, and our suspension trauma article explains why.
Where programs fall short
Many organizations run strong fall protection programs. They select the right equipment, train for the fall, and keep harness inspections current. Rescue deserves the same attention, because the fall is the emergency everyone pictures and the suspension that follows is easier to overlook. Closing that gap means planning the rescue up front, keeping the right equipment at hand, and practicing until the crew can bring a worker down quickly and safely.
Choosing and rigging rescue equipment, from descent devices to SRL-Rs to rescue anchorages, is its own subject, and we will cover it in future articles.
Sources
- OSHA 29 CFR 1926.502(d)(20), prompt rescue (construction).
- OSHA 29 CFR 1910.140(c)(21), prompt rescue (general industry).
- OSHA Standard Interpretation, December 18, 2003, prompt rescue and rescue plans under 1926.502(d)(20).
- OSHA Standard Interpretation, April 27, 2004, rescue of a suspended worker following a fall event.
- ANSI/ASSP Z359.11-2021, Safety Requirements for Full Body Harnesses.
- ANSI/ASSP Z359.4-2013 (R2022), Safety Requirements for Assisted-Rescue and Self-Rescue Systems, Subsystems and Components.
- ANSI/ASSP Z359.14-2021, Safety Requirements for Self-Retracting Devices for Personal Fall Arrest and Rescue Systems.
- Rupert Noton and J. Nigel Ellis, Fall Protection Engineering, American Society of Safety Professionals, 2026.
- Turner, Wassell, Whisler, and Zwiener (NIOSH). Suspension tolerance in a full-body safety harness, and a prototype harness accessory. Journal of Occupational and Environmental Hygiene, 2008.
- International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Suspension syndrome: a scoping review and recommendations. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 2023.
- Australian and New Zealand Committee on Resuscitation (ANZCOR). Guideline 9.1.5, First Aid Management of Harness Suspension Trauma, April 2021.
Last reviewed: September 2026.
This article is for general informational purposes only. It is not legal, medical, or engineering advice, and it does not replace hands-on training, a site-specific hazard assessment, or the judgment of a competent or qualified person. Always follow the manufacturer’s instructions for your equipment and the regulations that apply where you work, and check with the authority having jurisdiction when in doubt. Standards, regulations, and research cited here were current when this article was written and may since have been revised, reaffirmed, or withdrawn. Fall Labs makes no warranty as to the completeness or accuracy of this information and is not responsible for how it is used. References to OSHA, ANSI, ASSP, or any other organization do not imply their endorsement.