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 19, 1993

Mr. David LeGrande
CWA Coordinator
Occupational Safety and Health
501 Third Street, N.W.
Washington, D.C. 20001-2797

Dear Mr. LeGrande:

Thank you for your letter of March 23, in which you requested a written interpretation of coverage for the telecommunications industry with regard to the new Permit-Required Confined Spaces (PRCS) standard 29 CFR 1910.146. I can make some general observations with respect to the relationship between the PRCS standard, which is a generic standard, and an industry-specific standard, such as the telecommunications standard, 29 CFR 1910.268.

The Occupational Safety and Health Administration (OSHA) provides clear guidance regarding the application of generic standards in 29 CFR 1910.5, Applicability of standards. In particular, 29 CFR 1910.5(c)(1) provides that a particular standard will supersede a generic standard when the "particular standard specifically [applies] to a condition, practice, means, method, operation, or process." Also, [29 CFR 1910.5(c)(2)] states that a generic standard "shall apply...to any employment [and place of employment] in any industry, even though particular standards are also prescribed for the industry...to the extent that none of such particular standards applies."

The telecommunication standard explicitly provides for the application of a generic standard in 29 CFR 1910.268(a)(3), Application, which states "[o]perations or conditions not specifically covered by this section are subject to all the applicable standards contained in this part 1910. See 1910.5(c)."

CFR 1910.146(c)(1) requires all employers, including telecommunications companies to determine if their workplaces contain any confined spaces that meet the definition of "permit-required confined space" (permit space). As a practical matter, an employer who already has information about the hazard(s) in the identified permit spaces may be able to comply with 29 CFR 1910.146(c)(1) without physically surveying each and every space.

Based on 29 CFR 1910.5(c)(1), OSHA has stated that where permit space hazards identified through compliance with paragraph (c)(1) are addressed by 29 CFR 1910.268(o), Underground lines, the telecommunications standard, not the permit space standard, applies (58 FR 4469). The Agency has also stated that, where compliance with 29 CFR 1910.146(c)(1) discloses that a telecommunications employer has permit spaces that pose hazards which are not addressed by 29 CFR 1910.268(o), the employer shall protect any employees assigned to enter those spaces through compliance with the pertinent provisions of 29 CFR 1910.146 (58 FR 4469, Footnote 4).

The measures required by the telecommunications standard (29 CFR 1910.268(o)) for the protection of employees working on underground lines divide into three categories as follows:



  • Protection from falling or from falling objects (29 CFR 1910.268;(o)(1)(i));
  • Availability of first aid assistance where there is reason to believe that safety hazards (such as vehicular or pedestrian traffic hazards not addressed by 29 CFR 1910.268(d)(1) or [1910.268(o)(1)(i)], unusual water hazards, and operations in manholes used jointly by a telecommunication utility and by an electric utility) are present (29 CFR 1910.268(o)(1)(ii) and [1910.268(o)(3)]; and
  • Testing the atmospheres of manholes and unvented vaults prior to employee entry and, where atmospheric hazards are detected, ventilating and taking any other measures necessary for safe entry (29 CFR 1910.268(o)(2)).

Therefore, 29 CFR 1910.268(o) rather than 29 CFR 1910.146 applies only to the extent that compliance with the above-described provisions adequately addressed the permit space hazards to which telecommunications employees are exposed.

Regarding your request for OSHA's thoughts as to whether the Agency should revisit the telecommunications coverage issue, OSHA believes that reconsideration is unnecessary because compliance with the existing regulatory scheme will provide comprehensive protection for telecommunications industry employees.

you have further questions regarding application of the standards, please contact [the Office of General Industry Enforcement at (202) 693-1850].


Roger A. Clark, Director
Directorate of Compliance Programs

[Corrected 4/6/2007]

March 23, 1993

Mr. Roger Clark
Director of Compliance Programs
Occupational Safety and
Health Administration
200 Constitution Avenue, N.W., Room N3468
Washington, D.C. 20210

Dear Mr. Clark:

I am writing to you on behalf of the 600,000 workers represented by the Communications Workers of America (CWA), AFL-CIO, CLC. Some 70,000 represented U.S. telecommunications employees have jobs requiring entry and work within confined spaces.

On January 14, 1993, the Occupational Safety and Health Administration (OSHA) issued the "Permit-Required Confined Spaces Standard for General Industry (1910.146)." As an advocate and supporter regarding the development and promulgation of the standard, CWA applauds OSHA for its action.

Regarding the standard's scope and application, CWA provided verbal and written testimony supporting the inclusion of the telecommunications industry within 1910.146. However, telecommunications industry representatives voiced their desire that telecommunications employers be excluded from coverage of 1910.146 as well as their desire that telecommunications employers continue to be covered by the OSHA Telecommunications Standard 1910.268.

As written, the OSHA Permit-Required Confined Spaces Standard does not specifically exclude the telecommunications industry from coverage. However in the preamble to the standard, in a very brief discussion of this issue, it is stated:

under current OSHA practice as outlined in Section 1910(c), confined spaces that are presently regulated in other sections of part 1910 will continue to be regulated under those sections to the extent that permit spaces are already regulated under those sections.



This has led to a certain amount of confusion as to whether the telecommunications industry is excluded from 1910.146 and, if so, in part or entirely.

As a result of this scenario, CWA requested clarification of the standard's coverage of the telecommunications industry. In discussions with Mr. Don Kallstrom, employed within OSHA's Office of Compliance Programs, my office was provided initial clarification. Mr. Kallstrom stated that the telecommunications industry was covered by both 1910.146 and 1910.268. That is, 1910.146 would apply when evaluating whether the confined space work environment:



  • contains or has the potential to contain a hazardous atmosphere;
  • contains a substance that has the potential for engulfing an entrant;
  • has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or
  • contains any other recognized serious safety or health hazard.

If a hazardous work environment was identified, 1910.146 would apply. However, after completing the evaluation, if a hazardous or potentially hazardous work environment was notidentified, 1910.268 would apply.

Mr. Kallstrom indicated that such clarification would be provided in the OSHA Field Operations Manual by April 15, 1993, the effective date of 1910.146.

CWA has communicated the above interpretation to its Regional Vice Presidents. In turn, this information has been provided to represented telecommunications companies.

The response from all telecommunications employers has been that they are not covered by 1910.146 at all.

As a result of the response from representatives of the New York Telephone Company, CWA's regional office in New York City requested an interpretation of coverage provided by 1910.146. The OSHA Regional Administrator responded stated that, as stipulated by 29 CFR 1910.5(c)(1) providing for a specific standard (in this case 1910.268) to supersede a generic standard (in this case 1910.146).

confined spaces which are presently regulated in other specific standards of Part 1910 will continue to be regulated under those sections. For example, telecommunications work in manholes and underground vaults is normally covered under the telecommunications standard, paragraph 1910.268(o). The provisions of 1910.146 would not apply as the provisions of 1910.268(o) protect against the hazards within the manhole or vault. However, confined spaces other than manholes and underground vaults which are entered by telecommunications employees are covered by 1910.146" (see attached correspondence).

CWA believes the Regional Administrator incorrectly interpreted the standard. The union suggests that the aforementioned statement:

Under current OSHA practice, as outlined in Section 1910.5(c), confined spaces that are presently regulated in other sections of Part 1910 will continue to be regulated under these sections, to the extent that permit spaces are already regulated under these sections.

clearly states that there may be instances (e.g., evaluation of environmental conditions and hazardous work environments) where 1910.146 would apply.

In addition, in the January 14, 1993 Federal Register, in which the final rule is contained, footnote 4 at the bottom of page 4469 provides another condition in which telecommunications employers would be covered by 1910.146:

Taking the telecommunications examples further, the Agency can envision manholes that may be more appropriately covered by 1910.146. Although it is rare, manholes can become overwhelmingly contaminated with toxins or other hazardous chemicals. If the work area could not be made safe before entry as required by 1910.268(o)(2)(i)(B), entry would have to be performed under the provisions of 1910.146.



Given the above, CWA would appreciate a written interpretation regarding coverage of the telecommunications industry by 1910.146, the Permit-Required Confined Spaces for General Industry Standard. In addition, the union would appreciate your thoughts as to whether, specific to the telecommunications industry, coverage issues of 1910.146 should be reconsidered or re-visited.

Thank you for your prompt attention to this matter. If you have any questions regarding the union's request, please feel free to contact me at (202) 434-1160.


David E. LeGrande
CWA Coordinator
Occupational Safety and Health