4.4 Tagout done right, and the neighbouring standards

1 When tagout is the correct answer

There is exactly one situation in which tagout is simply required, and one in which it is permitted.

Required: 1910.147(c)(2)(i) — if an energy isolating device is not capable of being locked out, the energy control program shall utilize a tagout system. Permitted: 1910.147(c)(2)(ii) — if the device is capable of being locked out, the program shall utilize lockout, "unless the employer can demonstrate that the utilization of a tagout system will provide full employee protection as set forth in paragraph (c)(3)."

And "capable of being locked out" is a demanding definition, as Part 1, Chapter 3 covered: a device qualifies if it has a hasp or built-in locking mechanism, or if lockout can be achieved without dismantling, rebuilding, replacing or permanently altering it. Bolt-on valve and breaker lockouts mean most devices in a modern plant qualify — and 1910.147(c)(2)(iii) requires new and majorly modified equipment to be designed to accept a lock. The population of legitimately unlockable devices shrinks every year.

2 What "full employee protection" costs

1910.147(c)(3)(i) requires that where a tag is used on a device capable of being locked out, the tag be attached at the same location the lock would have been, and the employer demonstrate that the tagout program provides a level of safety equivalent to a lockout program. (c)(3)(ii) explains what that demonstration takes: full compliance with all tagout-related provisions of the standard, together with such additional elements as are necessary — and it names examples of the additional safety measures to be considered.

Add to that the extra training of (c)(7)(ii) — six tag limitations — and the wider periodic inspection of (c)(6)(i)(D), which reviews responsibilities with every authorized and affected employee plus those limitations. A properly run tagout system is more work than lockout, every year, forever. That is the standard's design: it makes the less protective option the more expensive one.

3 Machine guarding: the standard on the other side of the fence

1910.147(a)(2)(ii) sends normal production operations to subpart O, and 1910.212(a)(1) is what waits there: one or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, ingoing nip points, rotating parts, and flying chips and sparks. Machine guarding was the tenth most frequently cited federal standard in fiscal year 2025.

The two standards hand the machine back and forth. Production runs under guarding. Servicing runs under energy control. The dangerous ground is in between — the jam clearance, the quick adjustment, the "I only need to reach in for a second." Part 1, Chapter 2 covered exactly where that boundary sits: guard removed or bypassed, or a body part into the point of operation or a danger zone during the cycle, and 1910.147 applies unless all four conditions of the minor servicing exception are met, alternative protective measures included.

And when the servicing is done, 1910.147(e)(1)'s requirement that components be "operationally intact" is what puts the guards back before the machine returns to production. Neither standard covers a machine running with a guard left in the maintenance shop.

4 Electrical work, confined spaces, and construction

The construction rows are worth dwelling on, because 1910.147(a)(1)(ii)(A) excludes construction outright and the 1926 replacements are much shorter. There is no written procedure requirement, no periodic inspection requirement, and no detailed device specification in 1926.417. Many contractors nevertheless build their programs on the 1910.147 structure, because it is the only complete model available and because a host plant will usually require it under 1910.147(f)(2) anyway.

5 Where consensus standards fit

Two documents come up constantly in lockout conversations and neither is an OSHA regulation. ANSI/ASSP Z244.1 is the American national consensus standard on the control of hazardous energy, published by ASSP; it covers alternative methods and risk-assessment-based approaches in more depth than 1910.147 does. NFPA 70E is the consensus standard on electrical safety in the workplace, published by NFPA, and is where most employers get their arc-flash and energized-work practices.

Both are copyrighted documents sold by their publishers, which is why this course names them and describes their role without reproducing their content. Neither is enforceable in itself. What OSHA enforces is 1910.147 and, for electrical work, subpart S — though an employer's own decision to follow a consensus standard can become part of what a competent program looks like at that site.

If your plant references Z244.1 or 70E in its program, get the current edition from the publisher and use it alongside the CFR text, not instead of it.

6 Where to go from here

You have been through the scope, the vocabulary, the program, the energy sources, the isolation points, the stored energy, the six steps, verification, release, group work and the paperwork. Three things are worth doing next.

Take the final exam for this course and go back to any part where a question surprised you. Four of its questions are marked safety-critical — the ones where being wrong on a plant floor can kill somebody — and they point you at the chapter to reread.

Read your own plant's procedure for a machine you work on, with the twelve-question checklist from Chapter 1 of this part in your other hand. If the procedure fails several of those questions, you have found something worth raising, and our free LOTO procedure generator will build a properly structured replacement in a few minutes.

Check your knowledge against the standard rather than against habit. The free lockout/tagout practice test is 25 questions with every explanation traced to its paragraph. And remember what this course is: a study aid. The training that 1910.147(c)(7) requires comes from your employer, on your machines, with your procedures, and it is certified by them under (c)(7)(iv). Nothing is issued here.