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    LOTOLockout / Tagout

    Definition

    Lockout/Tagout — procedures for controlling hazardous energy during covered servicing and maintenance work.

    Editorial definition: The QHSE Standard, updated 3 October 2026 · https://qhsetech.com/glossary/loto

    Scope: US OSHA 1910.147 has defined scope and exceptions. A digital record supports the procedure but cannot perform physical energy isolation.

    Example for your evaluation: Ask how a sample record preserves equipment identity, authorised roles and verification evidence.

    Sources checked: . Examples are editorial illustrations.

    What OSHA 1910.147 requires

    In US law, lockout/tagout is governed by 29 CFR 1910.147, the control of hazardous energy. It covers the servicing and maintenance of machines and equipment where unexpected energisation, start-up or release of stored energy could injure employees, and it sets minimum performance requirements. Construction and agriculture employment are among the exclusions, and exposure to electrical hazards in electric-utilisation installations falls under subpart S instead.

    The definitions carry the substance. An energy isolating device physically prevents the transmission or release of energy: a manually operated circuit breaker, a disconnect switch, a line valve or a block. Push buttons, selector switches and other control-circuit devices are not energy isolating devices. Lockout places a lockout device on the isolating device so that the equipment cannot be operated until it is removed; tagout places a warning device indicating that it may not be operated.

    Procedures must set out the scope, purpose, authorisation, rules and techniques, with specific steps for shutting down, isolating, blocking and securing equipment and for placing, removing and transferring devices. Before work starts, the authorised employee verifies isolation and de-energisation. Each energy control procedure is inspected at least annually by an authorised employee other than those using it, and the employer certifies the inspection by machine, date, employees included and inspector. Group lockout and shift or personnel changes need procedures of their own.

    Sources opened :

    What a LOTO record holds in software

    • An energy control procedure per machine: energy sources, isolating devices and their locations, and the shutdown, isolation and release steps.
    • A device register tying each lock and tag to the person it belongs to.
    • An application record: who applied which device at which isolation point, when, and the result of the verification before work began.
    • Transfers at a shift or personnel change, and the release record when energy is restored.
    • The periodic inspection certification with the four items the standard names, and training records.

    Lockout or tagout?

    The two are not interchangeable under 1910.147. A lock physically prevents operation; a tag only warns. Where an isolating device can be locked out, a tag may be used instead only if it is attached where the lock would have gone and the employer shows that the tagout programme gives safety equivalent to lockout. LOTO is also narrower than a permit to work: a permit coordinates the whole job and records isolations as one of its precautions, while the energy control procedure is the isolation itself.

    A hypothetical example: clearing a jam on a conveyor

    This is an invented case, not a description of a real site or of what any regulator requires in a particular situation. A conveyor feeding a packing line jams, and a maintenance technician is asked to clear it. The equipment has a written energy control procedure that lists the electrical supply at a wall disconnect and a pneumatic line with a manual valve for the tensioner.

    The technician stops the conveyor from the control panel, which is not an isolation, then follows the procedure. She opens the disconnect, fits her personal lock and tag, closes and locks the air valve, and bleeds the residual pressure from the tensioner. Before touching anything she tries to start the conveyor from the panel to prove it cannot move, and returns the control to off. A colleague joins to help and fits a second lock on the same lock box. When the jam is cleared, each person removes their own lock, the area is checked for tools and people, and the supply is restored. Had the work run past the end of the shift, the incoming technician would apply a lock before the first was removed, so that protection is never absent. The record shows each lock, who applied it, the verification attempt and the release.

    Common misunderstandings about LOTO

    • Switching a machine off at the control panel is not lockout. A stop button interrupts a control circuit; it does not physically prevent energy from reaching the machine, and it can be operated by someone else.
    • Electrical energy is only one source. Stored energy in springs, hydraulic and pneumatic lines, elevated parts and capacitors, and flows of steam or product, can all injure a person after the power is off.
    • A lock does not protect a person unless it is theirs. Shared or borrowed locks, or one lock for a crew without a way to show who is inside, remove the individual control that the practice is built on.
    • Verification is not optional. Testing that the equipment cannot start, using a method set out in the procedure, is the step that separates having isolated something from believing that you did.
    • LOTO is not only for large plant. Small machines with a single energy source still have an isolation point, and the procedure may be short, but the identity of the device and who holds it still matters.
    • A signed digital checklist is not an isolation. It documents the steps; the isolation exists only when physical devices are in place on the equipment.

    How LOTO relates to other glossary terms

    Lockout/tagout is a narrow, physical control that other processes lean on, so it is often listed beside them.

    • Permit to work: coordinates a whole job and lists isolations among its precautions; the isolation record itself is the LOTO evidence.
    • Management of change: changes to equipment can add or remove energy sources, so procedures need review whenever a change is approved.
    • PSM: a separate US standard for hazardous chemical processes, with its own requirements that sit alongside rather than inside lockout.
    • Near miss: an unexpected start-up that harmed no one is a good example of an event to investigate and use to correct the procedure.

    Records and evidence that usually exist for LOTO

    • A written procedure for each machine or group of similar machines, showing energy sources, isolation points and the order of steps.
    • Photos or labels at isolation points that match the procedure, so a worker can identify the right device.
    • An inventory of locks, tags and lock boxes and the people they are issued to.
    • A record of each application: equipment, date, who applied which device, and the verification result.
    • Records of group or shift transfers, and of anyone who needed a lock removed by someone else.
    • The periodic inspection record, showing the procedure, date, and who carried out the review.
    • Training and retraining records for the people who perform or are affected by the procedure.

    What a software tool needs to capture for LOTO

    • A procedure per equipment item that can be version-controlled, with each step and each isolation point identified, not stored as a general document.
    • A way to tie each lock or tag to a person and to the equipment it was applied to, including multiple locks on a single point.
    • A verification field that has to be completed before the job can move to the work stage, with who tried and what they observed.
    • Support for transfer between shifts and for lock removal by someone other than the owner, with an escalation record.
    • A link between the isolation and any permit or work order covering the same job, so neither can be closed while the other is open.
    • Scheduling and reminders for periodic procedure review, with a record of the reviewer and the outcome.
    • Mobile or offline use at the machine, since the person applying a lock often has no reliable connection or a free hand for a form.

    Catalog profiles documenting lockout and isolation records

    Same rule for every product: tagged “Permit to Work”, “Permits to Work (PTW)”, “Control of Work”, “Industrial Safety”, “Safety Management” or “EHS Management”, with a sourced lockout/tagout or isolation capability in its record, or one the vendor stated to us, labelled as vendor-stated. Documented and conditional capabilities qualify; check the linked scope before treating a module as included.

    Ordered by how closely our sources document this process, not by quality. Sponsored placements are labelled. How lists are ordered

    All 18 matching profiles are shown. Documentation review, not hands-on testing or a claim of compliance.

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    Frequently asked questions

    Is a digital sign-off an energy isolation?

    No. A record can document the procedure and responsibilities; physical hazardous-energy control and verification remain essential.

    What is group LOTO?

    An arrangement for coordinating hazardous-energy control when several people are involved. Evaluate the actual procedure, individual protection and handover requirements.

    What does US OSHA say about inspections?

    For procedures covered by 1910.147, periodic inspection is required at least annually, by an authorised employee other than the person using the procedure being inspected.

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