Is Lockout Tagout a Legal Requirement in the UK?

Is lockout tagout a legal requirement in the UK? Not by that name. “Lockout/tagout” is the title of a United States standard — OSHA’s 29 CFR 1910.147 — and no UK regulation uses the phrase. But the duty behind it is very much UK law. Regulation 19 of the Provision and Use of Work Equipment Regulations 1998 (PUWER) requires equipment to have suitable means of isolation from all its energy sources and requires employers to stop re-connection putting anyone at risk, and regulation 12 of the Electricity at Work Regulations 1989 does the same for electrical equipment. HSE’s guidance tells employers to lock off machines where power could be switched back on. In practice, secure isolation — which is what LOTO is — is how you comply.

At a glance: Nexis CPD’s £9 Lockout Tagout (LOTO) course covers the types of hazardous energy, the law behind safe isolation, the isolation principle, LOTO equipment, lockout versus tagout, and preparing, isolating, locking, dissipating and verifying. It is CPD accredited and 100% online with a verifiable e-certificate, and any three courses cost £18. It is awareness training: it does not make anyone competent to isolate a particular machine or electrical system on its own, and it does not replace site-specific procedures, practical instruction or an electrical qualification where one is needed.

What does UK law actually require?

Several sets of regulations overlap. None of them mentions “LOTO”, but together they require exactly what a lockout procedure delivers: energy sources identified, isolated securely, and prevented from being reconnected while people are at risk.

• PUWER regulation 19 — isolation from sources of energy. Regulation 19 requires every employer to ensure that, where appropriate, work equipment “is provided with suitable means to isolate it from all its sources of energy”. Those means are not suitable “unless they are clearly identifiable and readily accessible”. And the employer “shall take appropriate measures to ensure that re-connection of any energy source to work equipment does not expose any person using the work equipment to any risk to his health or safety.”
• PUWER regulation 22 — maintenance operations. Regulation 22 requires that, so far as is reasonably practicable, maintenance operations involving a risk can be carried out while the equipment is shut down — or, where that is not possible, that other measures protect the person doing the work.
• PUWER regulations 8 and 9 — information, instruction and training. Everyone who uses work equipment, and everyone who supervises or manages its use, must have adequate information, instructions and training, including on the risks and precautions.
• Electricity at Work Regulations 1989, regulations 12 and 13. Regulation 12 requires suitable means for cutting off the supply and for isolating electrical equipment, and defines isolation as “the disconnection and separation of the electrical equipment from every source of electrical energy in such a way that this disconnection and separation is secure.” Regulation 13 requires adequate precautions to stop equipment that has been made dead from becoming electrically charged during the work.
• Management of Health and Safety at Work Regulations 1999, regulation 3. Employers must carry out a suitable and sufficient risk assessment, which is where the need for, and method of, isolation for each task is decided.
• Health and Safety at Work etc. Act 1974. The general duties to provide safe plant and safe systems of work sit underneath all of these.

These regulations apply in Great Britain; Northern Ireland has equivalent regulations enforced by HSENI. Breaching them is a criminal matter, and failures of isolation during maintenance, cleaning and unblocking are a recurring theme in HSE enforcement.

What is lockout tagout?

Lockout tagout is a procedure for making machinery and plant safe before people work on it, and keeping it safe until they have finished. The two words describe two different things:

• Lockout means physically securing an isolation device — a rotary isolator, a circuit breaker, a valve — in the safe position with a lock, so that it cannot be operated until the lock is removed.
• Tagout means attaching a tag to the isolation point that warns people not to operate it and identifies who applied it and why.

A tag on its own is a warning, not a barrier: it relies on everyone seeing it, understanding it and choosing to obey it. That is why UK guidance talks about locking off. HSE’s guidance on maintenance of work equipment says to “lock off machines if there is a chance the power could be accidentally switched back on” and to “lock off isolating valves” on plant and pipelines containing pressured fluid, gas, steam or hazardous material. Tags still matter — they tell people who is working and why — but they work alongside locks, not instead of them.

In UK workplaces you will hear the same process called safe isolation, lock-off, isolation and lock-off, or LOTO. They all describe the same principle.

Why isn’t an emergency stop or interlocked guard enough?

Because they are not isolation. HSE’s Approved Code of Practice and guidance on PUWER, L22 Safe use of work equipment, is explicit at paragraph 195: “control measures such as interlocked guards and emergency stop controls are not suitable as a means of isolation.”

The reason is simple. An emergency stop or a guard interlock stops a machine through its control system. The energy is still there, the control system can fail or be reset, and someone elsewhere can restart the equipment. Paragraph 196 of the same guidance defines isolation as “establishing a break in the energy supply in a secure manner, ie by ensuring that inadvertent reconnection is not possible.”

That distinction matters most for the quick jobs — clearing a jam, wiping a sensor, adjusting a belt — where it is tempting to hit the stop button and reach in. HSE’s introduction to machinery safety says machines should be “properly switched off, isolated or locked off before taking any action to remove blockages, clean or make adjustments.” Quick jobs are not exempt.

What types of energy need to be isolated?

More than just electricity. L22 says the most common sources of energy are “power, heat and pressure”, but that other sources may need to be considered in the risk assessment. A lockout procedure should identify every source that could cause harm, including:

• Electrical — mains supplies, control circuits, and separately fed auxiliary supplies that are easy to overlook.
• Hydraulic and pneumatic — pressurised oil or compressed air that can move actuators, rams and cylinders even after the pump or compressor stops.
• Mechanical and gravitational — springs, flywheels, raised loads, counterweights and parts that can fall or rotate under their own weight.
• Thermal — steam, hot water, hot surfaces and heated process fluids.
• Chemical and process — hazardous substances in pipework and vessels, where the job may also involve a confined space.
• Stored electrical energy — capacitors and batteries that can hold charge after the supply is disconnected.

L22 also points out that some energy cannot be isolated at all — the potential energy of a raised part, for example, or the chemical energy in a battery — and says there should be a means of preventing it affecting workers “by shielding, barriers or restraint”. That is why blocking, propping and restraining are part of a good lockout procedure, not an afterthought.

What are the steps in a lockout tagout procedure?

Every site should write its own procedure for its own equipment, but the core steps are consistent across HSE guidance and good practice:

1. Prepare. Identify the equipment, the job, and every energy source that needs isolating. Use the manufacturer’s instructions and site isolation diagrams. Decide whether the job needs a permit to work.
2. Notify. Tell operators and anyone else affected that the equipment is being shut down and isolated.
3. Shut down. Stop the equipment in the normal way using its operating controls, so that it comes to rest safely.
4. Isolate. Operate each isolating device — isolator, breaker, valve — to separate the equipment from each energy source. The isolation point must be the right one for this equipment: check, don’t assume.
5. Lock and tag. Each person working on the equipment applies their own personal lock to each isolation point, with a tag identifying them and the work.
6. Dissipate stored energy. HSE’s guidance says to “release any stored energy, such as compressed air or hydraulic pressure that could cause the machine to move or cycle”, support parts that could fall, let hot components cool, and put mobile plant in neutral with the brake on and the wheels chocked.
7. Verify. Prove the isolation works before anyone starts. For machinery, that often means trying the normal start controls (then returning them to off) and checking gauges read zero. For electrical work, it means proving dead with a suitable voltage indicator that has itself been checked — the guide to electrical safety at work explains safe isolation for electrical circuits in more detail.
8. Do the work — with the isolation maintained throughout.
9. Restore. When work is complete, check tools and people are clear and guards are refitted, then remove locks and tags in a controlled sequence and re-energise. PUWER regulation 19(3) exists because re-connection itself can hurt people; L22 adds that guards and protection devices must be working before operation begins.

What happens when more than one person is working on the machine?

Everyone gets their own lock. L22 paragraph 197 says that where more than one person is working on isolated equipment, “it may be necessary to provide a locking device with multiple locks and keys. Each will have their own lock or key, and all locks have to be taken off before the isolating device can be removed.” It adds that keys “should not be passed to anyone other than the nominated personnel and should not be interchanged between nominated people.”

The usual way to do this is a group lockout hasp: a clamp that fits on the isolator and has holes for several padlocks. The isolator cannot be operated until every padlock has been removed, so the last person to finish is the only one who can release it. On larger jobs, sites often use a lock box: the isolations are locked with a set of locks, the keys go into a box, and every worker puts their personal lock on the box.

Shift changes need special care. The outgoing worker should not simply hand over their key or remove their lock and leave the equipment unprotected. A good procedure has the incoming worker apply their lock before the outgoing worker removes theirs, so that the isolation is never left without a personal lock on it.

Does lockout apply to pipes and process plant?

Yes, and it becomes more demanding. HSE’s detailed guidance, HSG253 The safe isolation of plant and equipment, is written mainly for the oil, gas and chemical industries but is described as “generally applicable to any industry undertaking process isolations”. It warns that “all isolation methods can fail”, and that the performance of an isolation depends not only on the hardware but on the arrangements to “identify each isolation point, secure the isolation, prove/monitor the isolation and maintain overall control of the work”.

Some of its practical points apply well beyond chemical plants:

• Valves that need only a quarter turn to open, such as ball valves, should always be physically disabled and secured — by padlocking or removing the handle — because they can be knocked open.
• Each component of an isolation should carry an isolation tag, and tag numbers should match the isolation documentation.
• Isolations should be proved before intrusive work begins, and “secured, monitored and maintained throughout”.

L22 adds a point that surprises people: “The closed position is not always the safe position”. Drain or vent valves may need to be locked open, so that pressure cannot build up behind a closed isolation.

Is a permit to work the same as lockout tagout?

No, but they often work together. Lockout tagout is the physical method of isolating and securing energy. A permit to work is a formal written system for controlling high-risk work: it records what work is authorised, what hazards exist, what precautions — including isolations — have been put in place and checked, and when the equipment can be handed back.

HSE’s maintenance guidance says that for high-risk equipment “formal systems of work, such as a permit to work, are required in some cases”. HSE’s HSG250 Guidance on permit-to-work systems explains how they should be designed. Typical triggers include complex isolations, work involving several trades or contractors, confined space entry, hot work, and work on systems carrying hazardous substances. For simple, routine isolations of a single machine, a well-written lockout procedure may be enough on its own.

Who can carry out lockout tagout?

Only people who are authorised and competent for that equipment and that type of isolation. PUWER regulations 8 and 9 require adequate information, instruction and training for anyone who uses or maintains work equipment, and HSE’s maintenance guidance says maintenance should only be carried out by people who are competent to do the work. For electrical work, regulation 16 of the Electricity at Work Regulations 1989 requires technical knowledge or experience, or appropriate supervision, where it is needed to prevent danger.

Most sites define roles: people authorised to apply isolations, people who may work under an isolation someone else has applied, and people who may only apply a personal lock. Operators who only clear routine jams may be trained in a simple lock-off of their own machine, while complex or multi-energy isolations are restricted to maintenance staff or engineers. Contractors must work to the site’s procedure, and the site must make sure they understand it.

What equipment is used for lockout?

The equipment is simple; the discipline is what makes it work. Common items include:

• Personal safety padlocks, each with a single key held only by the person who applied it. Many sites use a distinctive colour reserved for isolation, so safety padlocks are never used for anything else.
• Lockout hasps that allow several people to lock the same isolation point.
• Breaker, plug and valve lockout devices for isolation points that have no built-in way of taking a padlock.
• Tags showing the name of the person, the date and the reason for the isolation.
• Lock boxes and lockout stations for larger jobs and for storing equipment where it is needed.

PUWER regulation 19(2) also requires the means of isolation to be “clearly identifiable and readily accessible”. If isolators are unlabelled, hidden behind stock or located somewhere awkward, people are far more likely to rely on the stop button instead. Labelling isolators to match the machines they serve is one of the cheapest and most effective improvements a site can make.

What goes wrong with lockout tagout?

The failures are rarely about hardware. They tend to follow a few familiar patterns:

• The quick job. Clearing a blockage or adjusting a sensor “only takes a second”, so the machine is stopped but not isolated.
• The wrong isolator. The isolation point is unlabelled or mislabelled, so the wrong equipment is locked off and the right one stays live.
• The forgotten energy. The electrical supply is isolated but hydraulic pressure, a raised part or a second supply is not.
• No verification. Nobody tries the start controls or proves the system dead, so an isolation that has not worked goes unnoticed.
• Shared keys and borrowed locks. One lock and one key are passed around the team, so the person removing it cannot know everyone is clear.
• Production pressure. People feel pushed to keep the line running and skip steps.

Every one of these is a management problem as much as an individual one. Clear procedures, labelled isolators, enough locks for everyone, supervision, and a culture in which stopping to isolate is expected rather than resented are what make the procedure stick. The guide to LOLER covers the related duties for lifting equipment, where maintenance and examination also depend on safe isolation.

Which courses support safe isolation?

Three £9 courses fit together well, each with a verifiable certificate for training records:

• Lockout Tagout (LOTO) — hazardous energy, the law behind safe isolation, LOTO equipment, and preparing, isolating, locking, dissipating and verifying.
• Permit to Work — how permit systems control high-risk work, including isolations, handovers and hand-back.
• Work Equipment Awareness — PUWER duties on suitability, maintenance, guarding, controls and training.

For teams whose isolations are mainly electrical, Electrical Safety Awareness is a useful alternative to the third course. Any three courses cost £18 because any three trigger the pay-for-2-get-3 offer. Add them to the cart and the discount applies automatically. These are awareness courses: they explain the principles and the law, but competence to isolate specific equipment comes from site procedures, practical instruction and, for electrical work, the appropriate qualifications and experience.

Frequently asked questions

Is lockout tagout a legal requirement in the UK?

Not by name. “Lockout/tagout” is a US OSHA standard. In the UK, PUWER regulation 19 requires suitable means to isolate work equipment from all energy sources and measures to stop re-connection putting people at risk, and the Electricity at Work Regulations 1989 require secure isolation of electrical equipment. Locking off is the standard way to meet those duties.

What is the difference between lockout and tagout?

Lockout physically secures an isolation device in the safe position with a lock. Tagout attaches a warning tag identifying who isolated the equipment and why. A tag alone relies on people noticing and obeying it, so UK guidance favours locking off, with tags used alongside locks.

Is pressing the emergency stop enough before clearing a jam?

No. HSE’s PUWER guidance says interlocked guards and emergency stop controls are not suitable as a means of isolation. HSE says machines should be switched off, isolated or locked off before removing blockages, cleaning or making adjustments.

Can two people share one padlock?

They should not. HSE guidance says that where several people work on isolated equipment, each should have their own lock or key, all locks must be removed before the isolating device can be operated, and keys should not be passed around or interchanged.

Does lockout tagout apply to hydraulic and pneumatic systems?

Yes. PUWER regulation 19 covers all sources of energy, not only electricity. HSE guidance says to release stored energy such as compressed air or hydraulic pressure that could cause a machine to move, and to lock off isolating valves on plant containing pressured fluid.

Do I need a permit to work as well as lockout?

Sometimes. HSE says formal systems such as a permit to work are required in some cases for high-risk maintenance, such as complex isolations, confined space entry or work on hazardous process plant. A simple single-machine isolation may be controlled by a lockout procedure alone, based on your risk assessment.

Isolate, lock, prove

£9 per course. CPD accredited, 100% online, verifiable e-certificate. Pay for 2, get 3 — any 3 courses for £18.

This article is general information, not legal advice. It describes the law in Great Britain; Northern Ireland has equivalent regulations enforced by HSENI. A Nexis CPD awareness course is CPD accredited but is not a regulated qualification; it does not authorise anyone to isolate specific equipment, and it does not replace site isolation procedures, practical training or electrical qualifications where they are required. Legal references are drawn from legislation.gov.uk and HSE guidance (L22, HSG253, HSG250 and HSE’s maintenance and machinery safety pages) at the time of writing.