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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.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

June 24, 1992

Mr. Daniel K. Shipp
National Electrical
Manufacturers Association
Suite 300
2101 L Street N.W.
Washington, D.C. 20037

Dear Mr. Shipp:

Thank you for your letter of January 6, addressed to Mr. Rolland Stroup of my staff. In this letter, you enclosed an August 14, 1991 letter addressed to Mr. Roger A. Clark, Director of Safety Standards Programs of the Occupational Safety and Health Administration (OSHA). In these letters, you requested written confirmation as to whom the lockout standards at 29 CFR 1910.147 are applicable. We apologize for the delay in responding.

Employers, not those who design electrical products, are required by OSHA standards to use energy control devices which are designed to be lockable, with the following exception: if an energy isolating device is not capable of being locked out, OSHA will allow employers to use a tagout program. When the employer has workplace machines or equipment which have energy control devices which have been designed to be lockable, the OSHA standards require the employer to use lockout unless the employer's tagout program can be shown to provide "full employee protection", that is, protection equivalent to lockout in the workplace.

The standard provides at 29 CFR 1910.147(c)(2)(iii) that original and replacement machines or equipment installed in the workplace after January 2, 1990 shall be designed with lockout-capable energy isolating devices. Also, whenever major repair, renovation or modification of a workplace, machine or equipment is performed after January 2, 1990, the employer must install energy isolating devices for such machines or equipment, designed to accept a lockout device. As a matter of policy, OSHA currently enforces this provision of the standard by means of citing the employer.

We will provide copies of your letters and this response to all of our OSHA Field Offices. Also, we will add this correspondence to our interpretations data base for future access.

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


Patricia K. Clark, Director
Directorate of Compliance Programs