What is an energy isolating device?
An energy isolating device is a mechanical device that physically prevents the transmission or release of energy, such as a manually operated circuit breaker, a disconnect switch, a line valve or a block. Push buttons and selector switches are not energy isolating devices.
By Cairn. Updated . Sources: eCFR text as of October 27, 2026.
The legal definition
“Energy isolating device. A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy. Push buttons, selector switches and other control circuit type devices are not energy isolating devices.”
Where it applies
- 29 CFR 1910.147, The control of hazardous energy (lockout/tagout) 22 paragraphs use the term. Read the text on eCFR.
- 29 CFR 1910.269, Electric power generation, transmission, and distribution 17 paragraphs use the term. Read the text on eCFR. Not the same definition: 29 CFR 1910.269(x) defines the term in its own words, as a physical device with a visible indication of its position, and with its own list of examples.
In the enforcement record
Federal and state-plan agencies issued 50,526 cited violations under 29 CFR 1910.147, The control of hazardous energy (lockout/tagout), from January 2016 through September 10, 2026. The section ranks 4th among the 248 sections of 29 CFR cited at least 50 times. This is the count for the whole section, not for the term alone.
Cairn data, October 2026 snapshot.
See the full record for 29 CFR 1910.147Sources
- 29 CFR 1910.147, The control of hazardous energy (lockout/tagout). eCFR, text as of October 27, 2026.
- Cairn data, October 2026 snapshot. Cairn analysis of the OSHA enforcement record.
Written by Cairn, updated . The quoted text is copied from the sources above. A test compares each quotation with a stored copy of the source, and a separate script compares that copy with the live sources. This page explains the law and is not legal advice.