OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

May 3, 2001

Mr. Craig Jorsch
Safety Coordinator
International Union Operating Engineers, Local 150
20959 West Lockport Road
Plainfield, IL 60544

Re: §1926.800(c) and 1926.800(f)(5); Employees working alone in a tunnel or a shaft connected to a tunnel

Dear Mr. Jorsch:

This is in response to your December 12, 2000, letter in which you ask the Occupational Safety and Health Administration (OSHA) to clarify the application of 29 CFR 1926.800(c) and (f)(5) to lone employees working underground in a tunnel or shaft connected to a tunnel.

29 CFR 1926.800 (Subpart S) is the underground construction standard. Section 1926.800(a) ("Scope and Application") explains that Subpart S "applies to construction of underground tunnels, shafts, chambers and passageways." Subpart S "also applies to cut-and-cover excavations which are both physically connected to ongoing underground construction operations within the scope of this section, and covered in a manner as to create conditions characteristic of underground construction." Section 1926.800(a) limits the standard’s coverage by expressly excluding certain operations. The two exclusions are 1) "excavation and trenching operations covered by Subpart P of" Part 1926 so long as they "are not physically connected to underground construction operations" and 2) "underground electrical transmission and distribution lines, as addressed in Subpart V of" Part 1926.

As discussed below, all provisions of Subpart S apply where at least one employee is engaged in work covered by Subpart S. Additionally some provisions of Subpart S apply only where a worker is working alone.

Application of §1926.800
None of the provisions of Subpart S are contingent on the presence of more than one employee. While some provisions use the word "employees" or "persons," the terms are used to mean "any and all employees."

For example, you specifically asked about §1926.800(c) (Check-in/check-out), which provides:

the employer shall maintain a check-in/check-out procedure that will ensure that aboveground personnel can determine an accurate count of the number of persons underground in the event of an emergency.

The one exception to this requirement is that:

... this procedure is not required when the construction of underground facilities designed for human occupancy has been sufficiently completed so that the permanent environmental controls are effective, and when the remaining construction activities will not cause any environmental hazard or structural failure within the facility.

The provision, by its terms, is designed to enable the employer to obtain "an accurate count of the number of persons underground." The provision would make little sense if it applied only where the total number of persons is more than one. For example, if three workers had departed in the morning, and only one was left in the afternoon, the purpose of the provision would be defeated if it ceased to apply once the first three left. The provision is designed to give the employer "an accurate count" — in this example, the employer has as much of a need to know in the morning that all four workers are underground as it has to know in the afternoon that one worker is underground in the afternoon.

This is equally important on sites where there is only one worker assigned to the underground site. If an emergency were to arise, the employer would need to know if the employee was still underground, or if that worker had exited and was elsewhere.

Another example is §1926.800(g)(2) (Self-rescuers), which requires that:

The employer must provide self-rescuers approved by the National Institute for Occupational Safety and Health ... [These] respirators must be immediately available to all employees at work stations in underground areas where employees might be trapped by smoke or gas. The selection, issuance, use, and care of respirators must be in accordance with 29 CFR 1926.103. [Note §1926.103 requirements are identical to 29 CFR 1910.134, Respiratory Protection.]

This provision states that respirators must be immediately available to "all employees." If there is only one employee, then an employer that makes a respirator immediately available to its one employee has done so with respect to "all" of its employees. Use of the term "all" is simply a way of mandating that employers meet the requirements of the provision with respect to however many employees it has — including one. Also, as above, the hazard the provision addresses — suffocation or poisoning — is present irrespective of the number of employees at the site.

Similarly, §1926.800(e) (Notification), requires that:

(1) Oncoming shifts shall be informed of any hazardous occurrences or conditions that have affected or might affect employee safety...
(2) The employer shall establish and maintain direct communications for coordination of activities with other employers whose operations at the job-site affect or may affect the safety of employees underground [emphasis added].

"Employees underground" includes a lone employee since it is a common way of saying "however many employees that may be."

In sum, none of these hazards are extinguished simply by limiting the number of employees to one. With respect to all of the Subpart S provisions, there is nothing in the regulatory record to suggest that the hazard addressed by these requirements exists only when there is more than one employee, or that commenters or the Agency saw a need to limit these requirements to situations where multiple employees were entering or exiting.

You also asked specifically about §1926.800(f)(5). That provision states:

Any employee working alone underground in a hazardous location, who is both out of the range of natural unassisted voice communications and not under observation by other persons, shall be provided with an effective means of obtaining assistance in an emergency.

This provision, along with several others that apply where an employee works alone underground, addresses a hazard that only exists when an underground worker is working alone. The more general hazard of being beyond speaking distance with others is addressed by §1926.800(f)(1), which states that:

When natural unassisted voice communications is ineffective, a power-assisted means of voice communications shall be used...



Workers who are working alone face the added hazard of being unable to ask a fellow worker to obtain assistance in an emergency. To address that additional hazard, paragraph (f)(5) was added so that the lone worker could directly obtain that assistance.

In sum, provisions such as §1926.800(f)(5) address the additional hazards faced by those working alone underground. They do not suggest that these are the only hazards faced by lone workers. As discussed above, lone workers face the same hazards as those working in groups, so even when there is only one worker underground, all provisions in Subpart S apply.

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction

[Corrected 6/2/2005]