A lockout hasp gives several workers a place to attach personal padlocks to a compatible locking point. It does not isolate several energy sources simply because it has several holes. For equipment with electrical, pneumatic, hydraulic or other hazardous energy, first identify every required isolation point. Then decide how workers will maintain personal protection at those points, either through direct locking or an approved group arrangement. Count the energy-control points and the people separately before choosing hardware.
This article focuses on lockout hasps for multiple energy sources: how to avoid confusing worker capacity with isolation coverage, prepare a point-by-point plan and build a purchasing list. For the basic mechanism, see how a lockout hasp works. QVAND’s lockout hasp range provides hardware to assess against that plan.
Separate three counts before the shutdown
A maintenance planner needs three different numbers: hazardous energy sources, physical isolation points and exposed authorized workers. They answer different questions. A machine can have one electrical supply and several pneumatic branches, while several workers may all depend on the same set of isolation points. None of those counts can be obtained by looking at a hasp’s holes.
Start with the task boundary. Which equipment will be serviced, which parts will be accessed and what adjacent machinery or connected process could introduce a hazard? Use current drawings and a safe field review. Assign each relevant isolator a unique identifier so the written procedure refers to an actual component rather than a general instruction such as “lock the air.”
Under the application sequence in OSHA 29 CFR 1910.147, covered servicing requires identification and operation of the necessary isolating devices, lockout application, control of residual energy and verification. A hasp contributes physical retention; it cannot replace the source survey or prove that the machine is safe.
Why six holes do not mean six energy sources
A typical multi-hole hasp joins a compatible locking interface to several personal padlocks. Its jaw and closure determine how it attaches. The holes provide places for workers’ locks. They are not separate energy-disconnection channels, and the hasp has no way to detect which hazards have been controlled elsewhere.
Imagine, as a planning example, a machine requiring an electrical disconnect and a compressed-air isolation valve. Putting several personal locks on a hasp at the electrical disconnect does not also secure the air valve. The air isolation and any necessary residual-pressure controls need their own specified arrangement. The number of workers protected at the first point does not change that requirement.
Conversely, a machine might have more than one electrical isolator for a single energy type. Counting only “electricity” as one source would understate the physical work needed. Identify the components and their relationship to the task rather than assuming one device for each energy category.
Create an isolation-point matrix
The table below shows the fields to collect. It is an illustrative planning template, not a procedure for a specific machine. The appropriate verification method and acceptance criteria must be defined by competent personnel for the equipment and jurisdiction. Entries such as bleeding, blocking or testing are decisions to document, not instructions to improvise in the field.
| Planning field | What to record | What it prevents |
|---|---|---|
| Equipment and task | Asset ID, work boundary and exposed components | Using a procedure written for a different maintenance activity |
| Energy and isolator | Each hazardous source and the identified device that isolates it | Confusing a stop control with isolation, or missing a second supply |
| Locking interface | Eye or attachment geometry and compatible lockout device | Ordering a hasp that cannot capture the intended point |
| Personal protection | Workers at direct locks, or the approved group-control relationship | Assuming one shared lock accounts for everyone |
| Residual energy | Required discharge, restraint or other controls and reaccumulation risks | Assuming retained isolators remove stored hazards |
| Verification | Responsible person, method and recorded result | Treating a visible padlock as evidence of a safe energy condition |
| Restoration boundary | Who authorizes removal and how personnel are accounted for | Releasing a point while another task still depends on it |
The CCOHS lockout guidance offers a useful independent overview of the program and procedure information behind these fields. It provides Canadian guidance; use the law and equipment instructions applicable to the actual site.
Choose direct hasps or a group-lockbox arrangement
In a direct arrangement, each exposed authorized worker applies personal protection at the required points as specified by the procedure. Hasps may provide the needed attachment capacity where those interfaces are compatible. This can be easy to understand when points are accessible and the work boundary remains clear.
With many points, distant isolators or changing personnel, a documented group-lockbox method may be appropriate. Isolation locks secure the designated points, and their controlled keys are secured through the group arrangement. Workers’ personal devices then maintain the required relationship to those keys. The method must protect each participant; a box alone is merely a container.
For crew assignments and continuity, use the existing multi-crew group-lockbox planning checklist. The decision here is narrower: determine which physical points need hardware and how the personal-protection relationship will cover all of them. Do not choose a lockbox solely to reduce walking without reviewing verification, key custody and restoration.
Estimate hardware without turning arithmetic into approval
For a simple direct arrangement, a useful preliminary calculation is personal padlock placements = required directly locked points × participating workers, provided the procedure requires every listed worker to lock each listed point. This estimates placements, not a universal rule for every group method.
For example, four directly locked points and three workers produce twelve personal-lock placements. If each point requires one compatible hasp, the preliminary hasp count is four. These hypothetical numbers say nothing about whether the chosen hasp fits, whether the point can take a direct padlock without a hasp or whether a different group arrangement would be preferable.
Record spares separately from working quantities. Buying twelve locks does not establish an acceptable keying system, and buying four hasps does not prove that all sources have been found. Review the completed matrix before using the estimate as a purchase order. Identify any point needing a valve cover, breaker attachment, cable device or engineered restraint instead of a bare hasp.
Check each physical interface with the actual lock set
Measure the isolator’s locking feature, access path and surrounding clearance. Check the hasp jaw opening, internal space, closure and personal-lock holes as an assembly. A jaw that passes through an opening may still fail to capture it properly. A padlock that enters a hole may obstruct closure or prevent the other planned locks from fitting.
Use a sample of the intended hasp with the padlocks actually issued to workers. Do not approve a six-worker configuration from six empty holes alone. Check that the closed arrangement remains retained with each permitted combination and that identification can be read without disturbing the device.
QVAND’s steel lockout hasp product is the reference for the illustrations in this guide. They preserve the photographed sample’s six-hole handle, jaw and pivot. They do not demonstrate an approved installation or establish dimensional, environmental or electrical ratings. Confirm the supplied model documentation before use.
Assign verification rather than duplicating assumptions
Different hazards need different verification methods. A retained valve operator does not demonstrate that pressure has been relieved. A secured electrical disconnect does not by itself establish absence of voltage at an exposed work location. Let the equipment-specific procedure identify the necessary methods and the personnel authorized or qualified to perform them.
For the group-lockbox scenario addressed in OSHA’s July 27, 2023 interpretation, a primary authorized employee may verify isolation; other authorized participants must be informed of their right to verify and permitted to do so. Do not misstate this as a requirement that every worker independently repeat every test, or as permission to omit verification.
Give workers an identifiable basis for joining the job: the defined boundary, controlling procedure, current isolation status and personal-device requirements. If labels, equipment identity or conditions do not match the plan, stop and resolve the discrepancy. More padlocks on an uncertain arrangement do not improve the accuracy of its boundary.
Plan partial release before it becomes urgent
A job may require temporary energization for testing, or one maintenance activity may finish before another. Decide which points are shared and which tasks depend on them before work starts. Removing a lock at a common point can affect workers who are not visible from that location.
Use the site’s authorized process for any testing, repositioning or change to the isolation boundary. Communicate with all affected participants, account for their protection and re-establish the required controls before servicing resumes. Do not create an informal rule that a coordinator can remove personal locks whenever a schedule changes.
Shift changes also need explicit continuity. The procedure should identify who remains protected, who has joined or left, and what review is required before accepting responsibility. This is particularly important when the hasps remain in place but the people and task boundaries change.
Turn the matrix into a supplier-ready request
Send the required interface photographs, measured clearances, expected personal-lock combinations and environmental conditions to the supplier. List the points that need hasps separately from those requiring other lockout hardware. Request model-specific dimensions and samples for the exceptions rather than labeling all interfaces “standard.”
Retain the accepted model and permitted application list for reorders. Material substitutions, a different jaw profile or a change to the issued padlocks can affect an otherwise familiar installation. The equipment-specific products and signs checklist can help assemble the wider task inventory without losing the point-by-point detail.
Watch: connect hardware with the full lockout process
Workplace Safety & Prevention Services explains hazardous energy and the broader lockout sequence in this educational video. Use it as a discussion aid for the difference between fitting hardware and verifying protection, not as a machine-specific instruction.
Watch the WSPS lockout education video on YouTube.
Frequently asked questions
Can one six-hole hasp isolate six energy sources?
No. The holes provide attachment positions for personal padlocks. Each required energy-isolating point must be identified and secured through the approved equipment-specific arrangement.
Does every isolation point need a hasp?
No. Some points accept the required locks directly, while others need compatible attachments or a documented group method. Select hardware from the actual interface and procedure.
When should multiple isolation points use a group lockbox?
Consider it when the point layout, worker numbers or work sequence make it appropriate. Approve the complete key-custody, verification and personal-protection arrangement before use.
Is counting locks enough to approve a group lockout?
No. Counts support planning, but approval also depends on the correct isolation boundary, hardware fit, stored-energy controls, verification and protection of every participant.
Review the referenced QVAND product and send your application details for a model-specific sample discussion.