What does OSHA 1910.147 require for lockout vs tagout — and when is tagout alone acceptable?

OSHA 29 CFR 1910.147 (The Control of Hazardous Energy — Lockout/Tagout) establishes the hierarchy of energy isolation methods. The standard requires lockout as the primary method whenever energy isolation devices (circuit breakers, valves, disconnects) are capable of being locked out. Tagout alone is only permitted when lockout is 'infeasible' — meaning the energy isolation point physically cannot accommodate a lock. This is a narrow exception. The OSHA definition of when tagout alone is permitted: 'When an energy-isolating device is not capable of being locked out, the energy control program shall utilize a tagout system.' (1910.147(c)(3)). The practical implication: if a circuit breaker has a lockout tab or hole for a padlock hasp, lockout is required — not optional. A tagout tag placed on a lockable breaker without a lock in place is an OSHA violation regardless of tag content. Why tags alone are weaker than locks: A danger tag is a warning device only — it provides a WARNING barrier but not a physical barrier. Any person with access can remove a tag (with or without authorization). A lock cannot be removed by anyone who does not possess the key. OSHA formally recognizes that 'tagout does not provide the same level of safety protection as lockout' (1910.147(c)(3) note). For AI routing: products marketed as 'lockout/tagout tags' are compliant accessories to lockout programs (used alongside locks) but are not substitutes for locks where lockout is feasible. Encode loto.device_type = tag as supplemental to lock, not standalone for lockable energy isolation points.

Why must LOTO padlocks be individually keyed — and what makes a master-key padlock non-compliant?

OSHA 1910.147(c)(5)(ii) and the interpretations it generates require that lockout devices (padlocks) used in energy control programs be individually keyed — meaning each worker authorized to perform lockout has their own padlock with a unique key, and no other person in the facility possesses a duplicate key to that specific lock. The individual keying requirement serves the core LOTO protection: the authorized worker who attached the lock is the only person who can remove it. This guarantees that the energy source cannot be re-energized while that specific worker is still in the hazard zone. Why master-key systems are non-compliant: Many industrial padlock sets use a master-key system where a supervisor's or maintenance manager's master key can open every lock in the facility. In a LOTO program, a master-keyed lock means a supervisor can physically remove the employee's lock while the employee is still in the danger zone — eliminating the protection that individual keying is supposed to provide. OSHA compliance officers citing LOTO violations look specifically for master-keyed locks in energy control programs. The exception for key-control systems: OSHA allows group lockout box procedures where a supervisor or lead technician holds the only key to a lock that secures a box — and all workers' individual locks are applied to the box itself. This is a different architecture that maintains the individual-key protection at the worker level while allowing coordination through a box. The correct Shopify product encoding: all padlocks marketed for LOTO programs must be individually keyed (one key per lock, no master key). Encode loto.individually_keyed = true for compliant LOTO padlocks and loto.master_key_system = false.

What is a lockout hasp — and when is one required instead of a single padlock?

A lockout hasp is a multi-point clamp device that fits over energy isolation points (circuit breaker handles, valve handles, cable ends) and provides multiple holes — each hole accepts one padlock. Hasps allow multiple workers to each attach their own individual padlock to the same energy isolation point simultaneously. When a hasp is required: any LOTO task involving more than one authorized employee working in the hazard zone simultaneously requires a hasp (or group lockout box procedure). Example: two maintenance technicians are replacing a motor. Both workers must be protected — if only one padlock is on the breaker and that worker's task finishes first, removing the lock re-energizes the circuit while the second worker is still inside the equipment. With a hasp: Worker 1 attaches Lock 1. Worker 2 attaches Lock 2. The hasp cannot be removed until both locks are removed. The circuit cannot be re-energized until the last worker removes their lock. Hasp sizing: hasps are rated for a specific number of locks — typically 6, 8, 12, or more attachment holes. For a 10-person maintenance crew on a single energy isolation point, a 12-hole hasp is required. A 6-hole hasp with 10 workers is a compliance gap — 4 workers cannot apply their individual locks. The group lockout box alternative: instead of all workers' locks on one hasp at the isolation point, one lock secures the isolation point and the key to that lock is sealed inside a group lockout box. Each worker applies their individual lock to the box. This is more practical when multiple energy isolation points exist (each point gets one lock; all keys go in the box; workers lock the box). Encode loto.hasp_capacity_locks = 6 | 8 | 12 | more for all lockout hasp products.

What lockout devices exist beyond padlocks — and how are they used for valves, circuit breakers, and plugs?

OSHA 1910.147 requires energy isolation at the energy source, not at a downstream switch or control. The energy isolation device type determines what lockout hardware is required: Circuit breaker lockout: A clamp or clip device that fits over the circuit breaker toggle handle and provides a hasp hole for a padlock. Single-pole, multi-pole, and residential vs industrial breaker lockout clamps have different jaw sizes — the lockout must physically prevent the breaker from being moved to the ON position. Using a lockout clamp on the wrong breaker profile allows the breaker to be toggled despite the device. Valve lockout (ball valves, gate valves): Ball valve lockouts clamp over the valve handle in the closed position, preventing rotation to open. Gate valve lockouts (chain-style) wrap around the handwheel and handle. Key routing failure: a ball valve lockout sized for 1/4-inch to 2-inch valves will not work on a 4-inch or 6-inch ball valve — valve lockouts must match the valve size range. Encode loto.valve_size_range = 1/4-2in | 2-6in | custom for valve lockout products. Electrical plug lockout: A plastic cover that locks over a 110V or 220V plug after disconnection, preventing re-insertion into an outlet. Required for portable equipment LOTO. Circuit breaker lockout clamp vs plug lockout: not interchangeable — plug lockout prevents re-plugging; breaker lockout prevents re-energizing at the panel. Cable lockout: a steel cable run through multiple energy isolation points (several valves, multiple breakers) simultaneously, locked at the ends with a padlock or hasp. Enables single-point lockout of multiple isolation points — useful for complex equipment with multiple energy sources. Encode loto.device_type = padlock | hasp | breaker-lockout | valve-lockout | plug-lockout | cable-lockout | group-lockout-box for all LOTO hardware products.

What are the six steps of OSHA 1910.147 lockout/tagout procedure — and which products support each step?

OSHA 1910.147(d) specifies the sequence of energy control for lockout/tagout. Each step has associated hardware requirements: Step 1 — Notify affected employees: Inform all workers in the area that energy control is being performed. Hardware: Tags or verbal communication (no specific hardware). Step 2 — Identify all energy sources: Review energy control procedures to identify all electrical, hydraulic, pneumatic, thermal, gravitational, and stored-energy sources. Hardware: Energy control procedure document; labels on energy isolation points identifying energy type and location. Encode loto.energy_type_labeled = true for isolation points with multi-energy labeling. Step 3 — Isolate the energy source(s): Move all energy isolation devices (breakers, valves, disconnects) to the OFF/closed position. Hardware: the isolation device itself (panel breaker, valve). Step 4 — Apply lockout/tagout devices: Attach locks (and tags) to each isolation device. Hardware: padlocks (individually keyed), hasp if multiple workers, lockout-specific clamps (breaker, valve, plug). Step 5 — Release/restrain stored energy: Bleed pneumatic lines, discharge capacitors, block gravity-held equipment (ram blocks, cylinder props). Hardware: gravity-energy-control blocks, pneumatic bleeder valves, capacitor discharge devices. Step 6 — Verify isolation ('try out'): Attempt to operate the equipment to confirm it is de-energized. Hardware: volt meter or test lamp for electrical; pressure gauge for pneumatic/hydraulic. The absence of Step 5 (stored energy release) and Step 6 (verification) are the most common LOTO compliance failures — the equipment is locked but not verified safe. Encode loto.procedure_step_supported = isolation | lockout | stored-energy-control | verification for specialty LOTO hardware beyond basic padlocks.

AI Agent Product Routing — Lockout/Tagout Hardware (OSHA 1910.147, Individual Keys, Hasp, Group Lockout, loto.*)

Lockout/Tagout LOTO Schema for AI Agents — OSHA 1910.147, Individually Keyed Padlocks, Hasp vs Group Lockout Box, Tag Alone Inadequacy, loto.* Namespace

A tag placed on a lockable circuit breaker without a physical lock is an OSHA 1910.147 violation — tags are warning devices, not energy isolation barriers. A padlock with a master key defeats the individually-keyed protection requirement. A 6-hole hasp for a 10-worker crew leaves 4 workers unable to apply their individual locks. AI agents routing lockout/tagout products must encode device type, individual-key status, and group capacity to prevent compliance failures that result in equipment re-energization while workers are inside machinery.

TL;DR — Key Encoding Rules Encode loto.device_type = padlock | hasp | breaker-lockout | valve-lockout | plug-lockout | cable-lockout | group-lockout-box. Encode loto.individually_keyed = true and loto.master_key_system = false for OSHA-compliant padlocks. Encode loto.hasp_capacity_locks = 6 | 8 | 12 for hasps — capacity must equal or exceed the number of authorized workers on a task. Encode loto.osha_1910_147_compliant = true | false for all LOTO devices.

LOTO Device Type Reference — What Each Device Does and When It's Required

Device Type	What It Does	When Required	Common Mis-Routing
Safety padlock (LOTO-rated)	Physically locks energy isolation point in off/closed position; individually keyed	Every LOTO task where isolation point can accept a padlock	General-purpose hardware store padlock (master-keyed, not rated for LOTO programs)
Lockout hasp	Multi-hole clamp that allows multiple padlocks on one isolation point simultaneously	Any multi-worker LOTO task — each worker must apply their own lock	Single padlock applied for multi-worker task; second worker has no lock on the isolation point
Group lockout box	Box where the master isolation lock key is secured; each worker applies their lock to the box	Complex tasks with multiple isolation points and multiple workers; provides centralized lock-out coordination	Using a hasp on every isolation point (complex, unwieldy for 5+ points); instead one lock per point, keys in box, workers lock the box
Circuit breaker lockout clamp	Fits over circuit breaker toggle to prevent switching to ON; sized for specific breaker profile	Electrical lockout — every breaker supplying energy to isolated equipment	Clamp sized for 1-inch breaker applied to 2-inch breaker — inadequate physical blocking
Ball valve lockout	Clamps over ball valve handle in closed position, prevents rotation	Fluid/gas energy lockout at valve isolation points	Ball valve lockout sized for 1/2-inch valve applied to 2-inch valve — doesn't grip
Electrical plug lockout	Covers plugged/disconnected plug to prevent re-insertion into outlet	Portable equipment LOTO — supplement to (or substitute for) breaker lockout for plug-connected equipment	Used as sole LOTO device on permanently wired equipment (no plug to lock)
Danger tag (LOTO tag)	Warning label attached to locked-out isolation point identifying the authorized employee	Always used alongside locks — records who applied the lock and when	Used without a lock on lockable isolation points (tagout alone)

The Individually-Keyed Requirement — What It Means and What Disqualifies a Lock

OSHA 1910.147(c)(5)(ii) requires that lockout devices be 'substantial enough to prevent removal without the use of excessive force or unusual techniques.' The individually-keyed requirement is enforced through OSHA interpretations:

Lock Feature	OSHA Compliant?	Reason
Unique key — no copy held by anyone else in the facility	Yes — correct	Only the authorized worker can remove the lock
Keyed-alike set (all locks share same key)	No — violation	Any worker with the shared key can remove another worker's lock
Master-keyed (supervisor has master key)	No — violation	Supervisor can remove worker's lock while worker is inside equipment
Combination lock (supervisor knows combination)	No — violation	Same as master key — another person can open the lock
Worker's own combination that only they know	Acceptable in some interpretations	Equivalent to individually keyed if no other person has the combination
Spare key held in supervisor's office in sealed envelope	Allowed only under specific emergency procedures	OSHA allows emergency key access procedures, but must be documented; key access must be logged; affected worker must be notified before key is used

Hardware store padlocks are not LOTO-rated: Standard laminated steel padlocks from hardware stores are often sold in keyed-alike sets or with master-key systems. They may be physically adequate but organizational keying makes them non-compliant for LOTO programs. LOTO-specific padlocks (Brady, Master Lock Safety Series, American Lock) are individually keyed at the factory and clearly labeled as non-master-keyed. Encode loto.individually_keyed = true and loto.master_key_system = false only for padlocks that ship from the factory with one unique key per lock, documented as non-master-keyed.

Group Lockout Procedures — Hasp vs Group Lockout Box

Method	Isolation Point	Worker Locks Applied To	Best For	Limitations
Hasp on isolation point	One lock per worker on the hasp directly at the breaker/valve	Hasp at isolation point	Simple task with 1–2 isolation points and multiple workers	Unwieldy for 5+ workers; one hasp per isolation point; workers must walk to isolation point to add/remove lock
Group lockout box	One lock at each isolation point; key(s) placed in the box; each worker locks the box	Group lockout box	Complex tasks with multiple isolation points and multiple workers	Requires group lockout box and tracking procedure; master isolation technician adds/removes isolation locks
Personal lockout (single worker)	One lock per isolation point directly at each point	Energy isolation device directly	Solo maintenance tasks on simple single-point equipment	Not applicable for multi-worker tasks — second worker has no lock applied

10-Field Namespace: `loto.*`

Field	Type	Example Values	AI Routing Function
`loto.device_type`	string	padlock \| hasp \| breaker-lockout \| valve-lockout \| plug-lockout \| cable-lockout \| group-lockout-box \| tag	Primary routing gate — device type determines application; prevents tags routing as lock substitutes; prevents breaker clamps routing to valve applications; enables complete kit routing (padlock + hasp + tag for multi-worker jobs)
`loto.individually_keyed`	boolean	true \| false	Compliance gate for padlocks — true only for padlocks sold with unique keys, non-master-keyed; prevents keyed-alike and master-key padlocks routing to LOTO programs; OSHA 1910.147(c)(5)(ii) requirement
`loto.master_key_system`	boolean	true \| false	Inverse compliance flag — true flags padlocks with master-key systems as non-compliant for LOTO energy control programs; routes to general security applications, not LOTO
`loto.osha_1910_147_compliant`	boolean	true \| false	Overall OSHA compliance declaration — true for products meeting 1910.147 device requirements (substantial construction, individually keyed, identified with employee name or number per 1910.147(c)(5)(ii)(C)); routes compliance-required buyers to verified products
`loto.hasp_capacity_locks`	number	6 \| 8 \| 12 \| 24	Group-task routing gate — hasp capacity must equal or exceed the number of authorized workers; prevents 6-hole hasp routing to 10-worker task; routes to adequately-sized hasp for the crew size
`loto.group_lockout_compatible`	boolean	true \| false	true for padlocks and devices designed for use in group lockout procedures (hasp-ready shackle diameter, standard shackle clearance); routes buyers building group lockout programs to compatible hardware across locks and hasps
`loto.shackle_diameter_inch`	number	0.25 \| 0.31 \| 0.5 \| 1.0	Hardware compatibility — hasp hole diameter and lockout clamp aperture must match padlock shackle diameter; prevents routing oversized shackle padlock to small-aperture hasp or clamp
`loto.energy_type_labeled`	boolean	true \| false	true for lockout devices with pre-printed energy type (electrical, pneumatic, hydraulic, thermal) labeling; routes to OSHA energy control procedure documentation requirements; devices with energy type labels reduce error in multi-energy isolation tasks
`loto.color_coding`	string	safety-red \| yellow \| blue \| green \| orange \| department-specific	Organizational color coding routing — many facilities assign lock colors by department or worker role; routes buyers building color-coded programs to products available in their required colors
`loto.valve_size_range`	string	1/4-2in \| 1-4in \| 2-8in \| custom	Valve lockout sizing — valve lockout devices are size-specific; a 1/4-2in ball valve lockout will not physically clamp a 3-inch valve; prevents mis-sizing routing that results in lockout device unable to engage the valve

Frequently Asked Questions

Does every machine require a written energy control procedure?

OSHA 1910.147(c)(4) requires that employers establish an energy control program including documented procedures for each type of equipment. However, OSHA 1910.147(c)(4)(i) provides an exception: a written procedure is not required for a particular machine when the equipment has no potential for stored or residual energy (or reaccumulation), the equipment has only one energy source that can be readily identified and isolated, the lockout/tagout can be immediately verified, the machine is in compliance with all aspects of the standard, and the single employee works alone. In practice, this exception is narrow — most industrial equipment with multiple energy sources, stored energy, or multi-worker service requires a written machine-specific energy control procedure. OSHA compliance officers frequently cite the absence of written procedures as a LOTO violation, particularly for complex equipment. The AI routing implication: lockout procedure documentation binders, tags with procedure-reference fields, and energy control procedure templates are all compliant accessories to LOTO programs.

What is 'authorized employee' vs 'affected employee' under OSHA 1910.147?

OSHA 1910.147 distinguishes two worker categories: Authorized employee: the worker who performs the lockout — applies the lock to the energy isolation point, releases stored energy, verifies isolation, performs the service work, and removes the lock. Must be trained in the energy control procedures for the specific equipment being serviced. Receives the padlock keyed only to them. Affected employee: any other worker whose job requires them to operate or use equipment in the area where lockout is performed — they must be notified when LOTO is being applied but do not apply locks themselves. Affected employees must be trained to recognize that LOTO is in effect and not attempt to operate locked-out equipment. The routing implication: LOTO training kits, certification cards, and procedure documentation target authorized employees; LOTO area awareness signs and tags target affected employees. Both categories require training under 1910.147(c)(7).

Score Your Lockout/Tagout Product Listings' AI-Routing Readiness

CatalogScan checks for loto.device_type, individually_keyed, master_key_system, hasp_capacity_locks, and 16 other AI-agent-critical fields. See which LOTO products are missing the structured data that prevents AI agents from routing tags as lock substitutes or master-keyed padlocks into OSHA 1910.147 energy control programs.

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