LOTO Procedure FAQs

LOTO stands for ‘lock out tag out’, a safety system followed to isolate energy sources and prevent accidental start-up of machinery during maintenance or repair.

A lock out tag out (LOTO) procedure is a controlled process followed to isolate machinery or equipment from all energy sources before maintenance, cleaning, inspection, or repair work begins. It involves shutting down the equipment, applying a lock and tag to each energy-isolating device, verifying that all hazardous energy has been effectively isolated, and ensuring the equipment cannot be restarted until the authorised person removes their lock.

This structured approach prevents accidental energisation and protects workers from serious injury or death caused by moving parts, electricity, stored pressure, or other hazardous energy sources.

Lock out tag out is important because it prevents the unexpected start-up or release of hazardous energy during maintenance or servicing.

By isolating equipment and clearly identifying who controls the isolation, LOTO protects workers from serious injuries such as electric shock, crushing, burns, and amputations, and ensures employers meet their legal duties to provide a safe working environment.

Yes. Lock out tag out (often referred to as isolation procedures) is required by law under the Health and Safety at Work etc. Act 1974, the Provision and Use of Work Equipment Regulations 1998 (PUWER), and the Electricity at Work Regulations 1989, which mandate that dangerous energy must be isolated and secured before work is carried out.

Lock out tag out is required whenever machinery, plant, or equipment could start up, move, or release stored energy during inspection, cleaning, maintenance, repair, or servicing. It must be applied before any work is carried out that could expose someone to hazardous energy.

LOTO is not required when equipment is completely de-energised, isolated, and incapable of releasing any hazardous energy, and no servicing, maintenance, or intrusive work is being carried out that could expose a worker to harm.

It is also not required for normal production operations where guards, protection devices, or safe systems of work adequately prevent exposure to hazardous energy, and no part of the worker’s body enters a danger zone.

To report an incident under RIDDOR, you must submit the report to the Health and Safety Executive using their online RIDDOR reporting forms.

Different forms are available depending on whether you are reporting an injury, dangerous occurrence, or case of occupational disease.

For fatalities and major incidents, reports can also be made by telephone to the HSE Incident Contact Centre on 0345 300 9923.

Only incidents that meet the criteria under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 must be reported.

The employer, self-employed person, or person in control of the premises is legally responsible for submitting the report.

An authorised person is someone trained and permitted to carry out LOTO. They are responsible for isolating energy sources, applying locks and tags, verifying the isolation, and removing their own lock once work is complete. Authorised persons perform maintenance, servicing, or repair work where unexpected energisation could cause harm.

An affected person is someone who operates or works near the equipment being locked out but does not apply locks. Affected persons must be informed that LOTO is in place, understand why the equipment is unavailable, and know not to attempt to start or interfere with it.

Clear distinction between these roles is essential to prevent accidental re-energisation and ensure LOTO procedures are followed correctly.

The first step of the LOTO process is to identify and understand all energy sources that could pose a risk. This includes locating every hazardous energy source connected to the equipment (such as electrical, mechanical, hydraulic, pneumatic, thermal, or stored energy) and understanding how that energy could be released or re-energised.

This assessment ensures the correct isolation points are chosen before lockout begins.

The six steps of lock out tag out are:

1. Prepare for shutdown by identifying all energy sources, hazards, and required isolation methods.
2. Shut down the equipment using normal stopping procedures.
3. Isolate the equipment by applying the correct energy-isolating devices (such as switches, valves, or breakers).
4. Apply LOTO devices — each authorised person fits their own lock and tag to prevent re-energisation.
5. Release or restrain stored energy (for example, bleeding pressure, discharging capacitors, blocking movement).
6. Verify isolation by testing that the equipment cannot operate before maintenance or repair work begins.

LOTO devices are the physical tools used to isolate and secure hazardous energy sources during maintenance or servicing so machinery cannot be energised unexpectedly. This includes padlocks, hasps, valve and breaker lockouts, cable lockouts, and tags that identify who applied the isolation and why.

These devices form part of a safe isolation system required under UK regulations such as PUWER 1998 and help ensure equipment remains safely de-energised until work is complete.

A LOTO lock is a dedicated padlock used during lock out tag out to isolate hazardous energy so machinery cannot be energised while maintenance or servicing is being carried out.

Each lock is uniquely keyed so only the authorised person who applied it can remove it, preventing accidental start-up and protecting anyone working on the equipment.

Each LOTO padlock is normally supplied with two keys, and no other key should open that lock. One key is used by the person applying the lock, and the second is kept securely as a controlled spare for emergency use in line with company procedures.

This supports the core LOTO principle that only the person who applied the lock can remove it, helping to prevent accidental re-energisation and ensuring clear personal accountability during maintenance and servicing.

A LOTO tag must clearly identify who applied the lock, why the equipment is isolated, and when the isolation was put in place. Information includes the authorised person’s name, contact details, date and time of application, the reason for the lock-out, and any relevant warnings or instructions.

This information ensures only the responsible person can remove the lock and that anyone on site understands the nature of the isolation.

No. You should not use a normal padlock for lock out tag out.

LOTO padlocks must be purpose-designed for safety isolation. They must be clearly identifiable, uniquely keyed, durable, and used only for lock out tag out. Each lock should be assigned to one authorised person, with one key, so only that person can remove it.

Standard hardware-store padlocks are not suitable because they are often shared, not uniquely keyed, not clearly marked for safety use, and may also be used for lockers or toolboxes. This creates confusion and increases the risk of a machine being re-energised while someone is still working on it.

A group lockout is used when more than one person is working on the same machine or system and each individual needs personal control over the isolation.

A hasp is a scissor-style device fitted to a single isolation point that allows multiple padlocks to be attached. Each worker applies their own personal lock to the hasp, and the machine cannot be re-energised until every lock has been removed. This enforces the “one lock per person” rule, even when only one isolation point exists.

In larger or more complex jobs, a group lockout may use a lock box instead. The machine is isolated and locked by an authorised person, the isolation key is placed in the lock box, and each worker applies their own padlock to the box. The equipment remains safely isolated until the last worker removes their lock.

If work isn’t finished at a shift change, the equipment must never be left unlocked or re-energised.

The outgoing shift removes their personal locks only as the incoming shift applies theirs, ensuring the isolation remains continuous. This is done through a formal handover, where the status of the job, the isolation points, and any hazards are clearly explained.

In group lockout or lock-box systems, the process is controlled so that at least one authorised lock always remains in place. The machine must not be restarted until all work is complete and every personal lock has been removed following the agreed LOTO procedure.

Emergency lock removal under a lock out tag out (LOTO) procedure is only permitted as a last resort and must follow a strict, controlled process.

The usual procedure is that:

• The employer confirms the authorised person who applied the lock is not on site and cannot return to remove it themselves
• The equipment is checked to confirm it is safe to remove the lock, including verifying that no one is inside the danger zone
• The removal is approved by management and a competent person, often requiring more than one authorised signature
• The lock is removed using a controlled method, with the action documented in full
• The authorised person is informed as soon as possible that their lock was removed and why

Emergency lock removal must never be routine. It exists to prevent unsafe shortcuts while ensuring equipment is not re-energised until every reasonable check confirms it is safe to do so.

Lock out tag out training ensure workers understand how to control hazardous energy safely, prevent unexpected machinery start-up, and apply isolation and tagging procedures correctly during maintenance and servicing.

Training helps organisations comply with the Health and Safety at Work etc. Act 1974 and PUWER 1998, reduce downtime, and strengthen a culture of safety and accountability.

LOTO training has no legally fixed renewal period, but UK law is clear that refresher training is necessary. Under the Health and Safety at Work etc. Act 1974, employers must provide information, instruction, training, and supervision to ensure work is carried out safely, which includes giving refresher training whenever risks change or competence needs to be maintained.

The Provision and Use of Work Equipment Regulations 1998 (PUWER) also require employers to ensure workers receive adequate training for any equipment they use, meaning training must be refreshed when introducing new equipment, changing procedures, or where gaps in knowledge or safe practice are identified.