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Train the Trainer 101: Enclosed Space Rescue

Following is a treatment of the complex subject of enclosed space rescue and it’s a lot of information. I would like to just tell you what to do, but there is no single solution. Your background understanding of the relative standards, interpretations and directives is necessary for you as trainers and administrators to mount an effective enclosed space program.

Part of the confusion is the very particular language in the relative standards. There are a couple of important keys to proper interpretation. One is to be clear that an enclosed space is really a confined space, subject to 29 CFR 1910.146 – the permit-required confined space (PRCS) standard – with the exceptions allowed under 1910.269 for qualified employees.

A second important point is that it is your responsibility to understand and comply with the intent of the standards. Manufacturers have risen to the challenge and continue to develop safety tools and equipment to help us make the workplace safer. I say that to preface a discussion of the rescue tripod, a great tool, often perfect for rescue from a classified space, brought to us by manufacturers to meet a need. Although many will swear that they are, tripods are not required. Rule 1910.269(e)(3), “Rescue equipment,” states: “Employers shall provide equipment to ensure the prompt and safe rescue of employees from the enclosed space.” The preamble – one of the places we go to find out what OSHA means by its rules – states that the employer is to provide “equipment that will assure the prompt and safe rescue of injured employees. The equipment must enable a rescuer to remove an injured employee from the enclosed space quickly and without injury to the rescuer or further harm to the fallen employee. A harness, a lifeline, and a self-supporting winch can normally be used in this manner.”

This is the only language OSHA has used in describing the equipment for enclosed space rescue. It is important to note here that preamble language is best understood as explanatory material describing how OSHA got to the rules in the standard. I have often been told that OSHA requires tripods and “it’s in the preamble.” As you can see, it’s not. Now, let’s get to what OSHA does require.

About the Rules
First, 1910.269(e) is the enclosed space standard; 1910.269(t) is titled “Underground electrical installations.” Paragraph (t) does not supersede (e). In the definitions, an enclosed space is defined as a “working space, such as a manhole, vault, tunnel, or shaft, that has a limited means of egress or entry, that is designed for periodic employee entry under normal operating conditions, and that under normal conditions does not contain a hazardous atmosphere, but that may contain a hazardous atmosphere under abnormal conditions.”

I have heard enclosed space defined as a space where the only hazard is electrical, but this, too, is not necessarily true. Look closely at the definition and you will see that the defining factor is twofold. It is “designed for periodic employee entry” and also “may contain a hazardous atmosphere under abnormal conditions.” This hazardous atmosphere could be gas like H2S, but it could also be smoke from burning insulation. Here is the practical look at the hazard of enclosed spaces. They usually contain energized equipment. Energized equipment, in particular cable, is insulated and sometimes fails. The smoke from burning insulation is toxic, containing hydrogen chloride, phosgene that forms hydrochloric acid in the lungs and dioxins that form chlorine gas. This consideration should be a prime concern in rescue planning, especially in the case of aging equipment. A person exposed to smoke from a post-equipment or cable failure will be instantly overcome and unable to self-rescue. A rescuer will not be able to look into – much less enter – a manhole belching toxic smoke. This is the importance of the requirements for nonentry rescue discussed below.

The Equipment
OSHA requires that an attendant be able to provide rescue assistance from outside the space. OSHA also requires mechanical assistance if the space is deeper than 5 feet. Mechanical assistance could be a tripod with winch unless there are more people in the hole than can be accommodated by the tripod. The multientrant solution could be a capstan-type winch and side open pulley on a rescue frame so more than one line can be accommodated, or it could be a sheave suspended on a digger derrick boom with a bumper-mounted capstan to do the mechanical work. Ultimately, the employer has to decide which method of nonentry rescue will meet the requirements. Here is a key point: In an interpretation from 1994 regarding enclosed space rescue, OSHA cited 1910.146(d)(9), the confined space standard, and stated: “[T]he responsible employer will have to practice and demonstrate that the procedure, equipment and personnel are sufficient for rescue for each space where it is applied.”

They also cited the above-referenced preamble citation as follows: “[T]here are no specifications for rescue equipment” and “whether your equipment would be sufficient will depend on all the factors relating to each situation.” (Sweeney, September 9, 1994)

The employer must be able to demonstrate the solution. Whatever you decide to do, it must be tested to see if it will actually work and the users must be trained. I have found several times that when the employer actually tries to perform a rescue, the whole process changes.

Nonentry Rescue
The standard does not use the term nonentry rescue, but does several times make reference to the requirement that the attendant remain outside the space. Part of the confusion arises from trying to combine (e) with (t) because (t)(3)(ii) allows the person outside to “briefly enter a manhole to provide assistance,” but that provision is unambiguously followed by “other than emergency.” Rule (e)(7) clearly states that the attendant “shall be immediately available outside the enclosed space to render emergency assistance.”

OSHA has issued numerous interpretations expressing the agency’s intent that the rescue by an attendant be nonentry. However, the agency does allow an entrant to enter a safe space to assist an injured person when relieved by another person qualified to serve as an attendant if, prior to entry, the space is checked for atmospheric and other hazards to ensure it is still classified as enclosed, not PRCS.

Guidance to CHSOs enforcing the 1910.269 standard seems to contradict the direct wording of the standard by stating that in an emergency, an attendant who has determined that there is no hazardous atmosphere and risk “could summon rescue services, enter the enclosed space, and administer first aid” to the injured party. (CPL 2-1.38, B-7)

But as stated earlier, the rule and interpretations have also allowed this practice when the attendant is relieved by another qualified attendant. This guidance to CHSOs follows the explanation that an enclosed space is by definition also a confined space depending on the atmosphere. The guidance ends by advising that if it is unsafe to enter, without nonentry rescue in place, the injured cannot be removed until rescue arrives.

However you decide to resolve this issue, I can think of several serious conditions that could arise if a lone attendant disappeared into a manhole to assist an injured co-worker and left the topside unattended. Ultimately, prepared and effective nonentry rescue solves all the issues as OSHA intended.

Third-Party Rescue Services
The threat to our co-workers in energized manholes or enclosed spaces is real and the solution is complicated. For that reason, some employers decide to use third-party rescue as provided for in the PRCS standard, which usually means the fire department. OSHA’s guidance on confined space enforcement to CHSOs says of rescue services: “Rescue services (on-site and off-site) are required by paragraph (k) to have members who are trained, equipped, and practiced for safe entry into the particular permit spaces from which they will be expected to rescue entrants.” (CPL 02-00-100, V)

I hope this treatment of enclosed space rescue helps you understand and competently approach worker safety. Your input on these “Train the Trainer 101” articles is important. I invite you to send your questions or comments either directly to me or to Kate Wade at Incident Prevention.

About the Author: After 25 years as a transmission distribution lineman and foreman, Jim Vaughn has devoted the last 15 years to safety and training. A noted author, trainer and lecturer, he is director of safety for Atkinson Power. He can be reached at

Editor’s Note: “Train the Trainer 101” is a regular feature designed to assist trainers by making complex technical issues deliverable in a nontechnical format. If you have a topic idea for a future issue, please contact Kate Wade at

Worksite Safety

Jim Vaughn, CUSP

After 25 years as a transmission-distribution lineman and foreman, Jim Vaughn, CUSP, has devoted the last 24 years to safety and training. A noted author, trainer and lecturer, he is a senior consultant for the Institute for Safety in Powerline Construction. He can be reached at