Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

December 23, 1992

Mr. Henry R. Tessier
Manager/Chief Engineer
Boiler/Machinery Loss Prevention
Industrial Risk Insurers
85 Woodland Street
Hartford, Connecticut 06105-1226

Dear Mr. Tessier:

This is in response to your letter of April 14, regarding the applicability of 29 CFR 1910.147 lockout/tagout standards to contractor employers with employees at electric power generation, transmission and distribution work sites. The questions you asked and the corresponding replies follow.

Question 1:

Does the exemption of 29 CFR 1910.147 for utilities, as described in the standard, apply to non-utility firms performing work requiring lockout/tagout at sites, such as utility plants, when the utility plants are not covered by this standard?


As delineated in 1910.147(a)(1)(ii)(B), installations under the exclusive control of electric utilities for the purposes of power generation, transmission and distribution, including related equipment for communications or metering, are not covered by the 1910.147 lockout/tagout standard. In addition, this standard does not apply to outside (contractor) employers whose employees perform work at these installations. Installations that are not under the exclusive control of electric utilities, or that are not for one of the above specified purposes covered by 1910.147, and outside (contractor) employers must comply. Although 1910.147(a)(1)(ii)(B) does not cover certain installations, as noted previously, employers, including contractors, may be cited under the general duty clause, Section 5(a)(1), of the Occupational Safety and Health Act in situations involving employee exposure to hazardous energy when performing servicing and maintenance of machines and equipment.

As noted on page 36660 of the preamble to the Final Rule on the Control of Hazardous Energy Source (Lockout/Tagout) published in the Federal Register, Volume 54, Number 169 on Friday, September 1, 1989, the question of how similar non-utility installations should be regulated is an issue in the rulemaking proceeding on a new General Industry section, 1910.269, "Electric Power Generation, Transmission and Distribution" standard. Proposed rules on this new section were published in the Federal Register, Volume 54, Number 14 on Tuesday, January 31, 1989. Copies of these editions of the Federal Register are enclosed for your information.

Question 2:

Does an on-site agency, such as an utility, have the right to restrict or limit the use of lockout/tagout procedures at their facility to only one procedure, specifically their own, when multiple contractors with individual procedures are involved?


Lockout/Tagout procedures used by outside personnel (contractors, etc.) are covered by 1910.147(f)(2). This standard requires on-site employers and outside employers to inform each other of their respective lockout/tagout procedures. Furthermore, an on-site employer is required to ensure that his personnel understand and comply with restrictions and prohibitions of the outside employer's energy control procedures. Outside employers are not required to use on-site employer lockout/tagout procedures.

Question 3:

What, in your opinion, would be IRI's (Industrial Risk Insurers) responsibility if an IRI loss prevention person were injured while using a procedure other than our own lockout/tagout procedure in the performance of an inspection which was mandated by local jurisdictional regulations?


As an employer, (IRI) is subject to occupational safety and health standards promulgated by Federal or State agencies, depending on the State in which the site is located. The Occupational Safety and Health Administration (OSHA) or State agency, as appropriate, may conduct workplace inspections initiated by complaints, reports of accidents involving fatalities and/or injuries to employees or other established inspection policy. During these inspections, employers who are found to be in violation of occupational safety and health multi-employer citation policy citations could be issued to both the on-site employer and the contract employer, depending on the circumstances.

Question 4:

Could an employee of one firm utilize another firm's lockout/tagout procedure and meet the requirements of 29 CFR 1910.147? What liability exposure do you foresee for both firms in this situation?


Within the context of 1910.147(f)(2) requirements, employees of outside employers, for example contractors, could utilize the on-site employers lockout/tagout procedures when these outside employees are trained in these procedures in compliance with 1910.147(c)(7). The duties and liabilities of employers with respect to providing for the safety and health of their employees remains unchanged. An outside employer would be responsible and could be held accountable, with respect to OSHA enforcement, for injuries sustained by his or her employee's resulting from the use of the on-site employer's energy control procedures, if determined to be deficient, that is, not in compliance with 1910.147.

Question 5:

Since our utility insureds are presently exempt from this procedure, when do you foresee implementation if at all, of a lockout/tagout procedure which would cover their industry? would IRI be able to review a draft of this document and provide comments?


Final action with respect to the enclosed proposed standard, Electric Power Generation, Transmission and Distribution, is scheduled for July of 1993. Public Hearings have been held and the periods for public comments have closed. You can provide comments to OSHA; however, any comments you submit may not be recorded as part of the rulemaking process unless the rulemaking record is reopened. "Ex parte" communications are permitted only when the rulemaking record is open.

Question 6:

Since 29 CFR 1910.147 specifies that utility plants are presently exempt from this standard, would independent power producers and electric power cogenerators be considered a utility under this standard, since they produce electricity for distribution to the utility distribution grid and utilize the same type of equipment in generating that power?


Consideration is being given to expanding the scope of the standard within the rulemaking procedure to installations for the generation, transmission or distribution of electric energy not owned or operated by electric utilities or work performed on such installations not owned by a utility. This potential expansion is discussed on page 4980 of the preamble to the proposed rules referenced in the reply to question 5.

Question 7:

Was OSHA aware of the insurance industry's involvement in the enforcement of boiler and pressure vessel regulations and the impact 29 CFR 1910.147 would have on the performance of these inspections prior to the development of this standard?


The Occupational Safety and Health Administration was aware of the insurance industry's involvement in the general servicing (inspection) of boiler and pressure vessels. Outside personnel servicing which requires lockout/tagout is covered by 29 CFR 1910.147(f)(2). As noted in the reply to question 2, servicing which requires lockout/tagout is covered also by 1910.269(d)(8)(iv) in the Proposed Rule on Electric Power Generation, Transmission and Distribution.

Thank you for your interest in occupational safety and health. If we may be of further assistance, please contact us.


Roger A. Clark,
Directorate of Compliance Programs