The definitions
| Lockout | Tagout | |
|---|---|---|
| What it is | Placing a lockout device on an energy isolating device, under an established procedure, so the isolating device and the equipment it controls cannot be operated until the lockout device is removed. | Placing a tagout device on an energy isolating device, under an established procedure, to indicate that the isolating device and the equipment it controls may not be operated until the tag is removed. |
| The device | Uses a positive means such as a key or combination lock to hold the isolating device in a safe position. Blank flanges and bolted slip blinds count. | A prominent warning device, such as a tag and a means of attachment, securely fastened to the isolating device. |
| Physical restraint | Yes | No. "Tags are essentially warning devices ... and do not provide the physical restraint on those devices that is provided by a lock" ((c)(7)(ii)(A)). |
| Source | 1910.147(b) | 1910.147(b) |
"Lockout/tagout" in everyday use usually means a lock and a tag together: the lock does the work, and the tag says who applied it and why. Under (c)(5)(ii)(D), lockout and tagout devices must identify the employee applying them.
When you must use lockout
- If the energy isolating device can be locked out, the program shall use lockout, unless the employer can demonstrate that a tagout system will provide full employee protection ((c)(2)(ii)).
- If it cannot be locked out, the program shall use a tagout system ((c)(2)(i)).
- New, replaced, majorly repaired, renovated or modified machines (after January 2, 1990) shall have energy isolating devices designed to accept a lockout device ((c)(2)(iii)).
In practice the "cannot be locked out" route is shrinking: most disconnects, breakers and valves now accept a lock or a lockout attachment, and anything you install, replace, majorly repair, renovate or modify has to.
Tagout alone on a lockable device: "full employee protection"
Paragraph (c)(3) sets the bar for using a tag where a lock would fit:
- The tag is attached at the same location the lock would have been attached ((c)(3)(i)).
- The employer demonstrates the tagout program gives a level of safety equivalent to a lockout program ((c)(3)(i)).
- That demonstration needs full compliance with every tagout-related provision of the standard plus whatever additional elements are needed for equivalent safety ((c)(3)(ii)).
- The demonstration shall include additional safety measures, such as removing an isolating circuit element, blocking a controlling switch, opening an extra disconnecting device, or removing a valve handle, to reduce the likelihood of inadvertent energization ((c)(3)(ii)).
That is a demonstration the employer has to be able to make, not a box to tick, which is why most programs simply lock out everything that can take a lock.
Requirements that apply to tags
| Requirement | Source |
|---|---|
| Singularly identified, the only devices used for controlling energy, and not used for other purposes | (c)(5)(ii) |
| Withstands the environment for the maximum expected exposure; does not deteriorate or become illegible in wet, damp or corrosive locations | (c)(5)(ii)(A) |
| Standardized within the facility in at least one of color, shape or size, and also in print and format | (c)(5)(ii)(B) |
| Means of attachment is non-reusable, attachable by hand, self-locking, non-releasable, with a minimum unlocking strength of at least 50 pounds, at least equivalent to a one-piece all-environment-tolerant nylon cable tie | (c)(5)(ii)(C)(2) |
| Identifies the employee applying it | (c)(5)(ii)(D) |
| Warns against hazardous conditions, with a legend such as Do Not Start, Do Not Open, Do Not Close, Do Not Energize, Do Not Operate | (c)(5)(iii) |
The six limitations of tags employees must be trained on
Where tagout systems are used, (c)(7)(ii) requires employees to be trained in these limitations of tags:
- Tags are warning devices and do not physically restrain the isolating device.
- A tag is not to be removed without authorization of the authorized person responsible for it, and is never to be bypassed, ignored or otherwise defeated.
- Tags must be legible and understandable by all authorized employees, affected employees and others who work, or may work, in the area.
- Tags and their attachments must withstand the environmental conditions in the workplace.
- Tags may evoke a false sense of security; their meaning needs to be understood as part of the overall program.
- Tags must be securely attached so they cannot be inadvertently or accidentally detached during use.
Tagout also changes the annual periodic inspection: where tagout is used, the review includes affected employees as well as authorized employees, and covers the tag limitations above ((c)(6)(i)(D)).
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Questions
What is the difference between lockout and tagout?
Under 29 CFR 1910.147(b), lockout uses a device such as a lock to hold an energy isolating device in a safe position so the equipment cannot be operated, while tagout uses a prominent warning device to indicate the equipment may not be operated. A tag gives no physical restraint.
Is tagout alone ever allowed by OSHA?
Yes, in two cases: where the energy isolating device cannot be locked out ((c)(2)(i)), or where it can but the employer demonstrates that the tagout program provides full employee protection equivalent to lockout ((c)(2)(ii), (c)(3)).
Do I need a tag if I already use a lock?
The standard requires lockout devices to identify the employee applying them ((c)(5)(ii)(D)). Many programs meet that with a tag attached to each personal lock, or with locks marked with the employee's name.
Can we use any padlock for lockout?
Lockout devices must be singularly identified, used only for energy control and not for other purposes, durable, standardized within the facility, substantial and identifiable ((c)(5)(ii)). A dedicated, standardized safety padlock per employee is the common way to meet that.
Related: Authorized vs affected employee · Group lockout/tagout procedure · Lockout/tagout program template · LOTO procedure example: hydraulic press brake
General information based on the text of 29 CFR 1910.147 on OSHA.gov; not legal advice. Check whether an OSHA-approved state plan applies to your workplace.