What Is Lockout/Tagout (LOTO) & Its Essential Components
What lockout/tagout (LOTO) means, the six procedure steps under OSHA 29 CFR 1910.147, and essential components such as safety padlocks, hasps, valve lockouts and tags.
Avenix Team
· 6 min read
IlustrasiSummary
Lockout/tagout (LOTO) is the procedure of isolating every energy source on a machine and then securing it with padlocks and tags before maintenance, so the machine cannot start up unexpectedly. The most widely used reference is OSHA 29 CFR 1910.147, and the core components are safety padlocks, hasps, lockout devices matched to each energy source, and warning tags.
Lockout/tagout (LOTO) is a safety procedure for isolating every hazardous energy source on a machine or piece of equipment, then locking it with a padlock and attaching a warning tag before maintenance or repair work begins. The goal is to make sure the machine cannot start up or release energy unexpectedly while workers are in the danger zone. The most widely used reference is OSHA 29 CFR 1910.147, The Control of Hazardous Energy.
This article explains what LOTO is, the types of energy that must be controlled, the procedure steps, and the components you need to have on hand.
Why is LOTO important?
Many maintenance accidents happen when a machine is assumed to be off but still holds stored energy, or when someone else switches it on without knowing that a worker is inside. The result can be electric shock, crushing, cuts, burns, or a spray of pressurized fluid.
LOTO prevents this with a simple principle: energy sources are disconnected, physically locked, tagged, and verified before work starts.
Types of energy that must be controlled
LOTO does not apply to electricity alone. Identify every energy source on the equipment:
| Energy type | Examples |
|---|---|
| Electrical | Panels, motors, capacitors |
| Mechanical | Flywheels, springs, rotating parts |
| Hydraulic | Pressurized cylinders and oil lines |
| Pneumatic | Compressed air in pipes and receivers |
| Chemical | Chemical pipelines and tanks |
| Thermal | Steam, hot surfaces, hot liquids |
| Gravitational | Raised loads, parts that can fall |
A single machine often has more than one energy source. A good LOTO procedure lists every isolation point for each piece of equipment.
Lockout vs tagout
- Lockout is the placement of a locking device, such as a padlock and lockout device, on an energy-isolating point so that the point cannot be physically operated.
- Tagout is the placement of a warning label on the isolation point stating that the equipment must not be operated.
A tag only gives a warning and does not physically prevent operation. For this reason, OSHA 29 CFR 1910.147 gives priority to lockout whenever the isolation point can be locked. Tagout alone is used only when the isolation point cannot be locked, with additional measures to provide equivalent protection.
Six steps of the LOTO procedure
Following the sequence of application in OSHA 29 CFR 1910.147:
1. Preparation
The authorized worker understands the type and magnitude of the energy, its hazards, and how to control it. Use the written procedure for that equipment.
2. Shutting down the equipment
Shut down the machine in the normal way, for example with the stop button or operating switch. Notify the operator and other affected workers.
3. Isolating the energy
Disconnect every energy source at its isolation point, for example a circuit breaker, disconnect switch, or valve.
4. Applying lockout/tagout devices
Each authorized worker attaches their personal padlock and a tag to every isolation point. Use the appropriate lockout device, such as a breaker lockout or valve lockout, so that a padlock can be fitted.
5. Releasing stored energy
Release or restrain any remaining stored energy, for example by bleeding off hydraulic and pneumatic pressure, discharging capacitors, blocking parts that could fall, and waiting for hot parts to cool down.
6. Verifying isolation
Before starting work, confirm that the equipment truly cannot operate. Try to start it with the normal controls, then return them to the off position. Use a test instrument to confirm there is no voltage present.
Removing LOTO after the work is finished
- Inspect the work area. Make sure tools and materials have been removed and machine guards are back in place.
- Make sure all workers are in a safe position and notify the affected workers.
- Each padlock is removed by the worker who applied it.
Essential LOTO components
OSHA requires LOTO devices to be singularly identified for energy control, durable, standardized (color, shape, or size), substantial enough that they cannot be removed without excessive force, and identifiable to the worker who applied them.
| Component | Function |
|---|---|
| Safety padlock | Each worker’s personal lock. The body is often made of non-conductive plastic, with one key per padlock (keyed different) |
| Lockout hasp | Allows several padlocks on one isolation point for group work |
| Valve lockout | Locks gate, ball, or butterfly valves in the closed position |
| Electrical lockout | Lockouts for circuit breakers, switches, plugs, and push buttons |
| Cable lockout | Flexible steel cable for locking several points or points with a non-standard shape |
| Lockout tag | “Do not operate” warning label with the worker’s name and date |
| Group lock box | Key storage box for group lockout on large jobs |
| LOTO station | Board or cabinet that stores all the equipment near the work area |
Choosing the right components
- Take inventory of the isolation points in your area, including breaker types, valve sizes and types, and plugs, before buying lockout devices.
- Use consistent padlock colors, for example by department or by function, so they are easy to recognize.
- Choose padlocks with a non-conductive body for electrical work.
- Provide hasps for jobs that involve more than one person.
- Place a LOTO station near the machine area so the procedure is not skipped because the equipment is hard to reach.
Common mistakes in LOTO implementation
- Only switching off the button on the operator panel. A stop button is not an energy-isolating point. Locks must be applied to the breaker, disconnect switch, or main valve.
- Using one padlock for the whole team. Every worker must attach their own personal padlock so the equipment is not switched on while someone is still working on it.
- Skipping verification. Without a try-start and a voltage test, isolation errors will go undetected.
- Forgetting stored energy. Pressure in pipes, springs, and raised loads remain dangerous even after the power has been disconnected.
- Using LOTO padlocks for other purposes, such as locking cabinets. LOTO devices must be dedicated to energy control.
A LOTO program needs more than equipment
OSHA 29 CFR 1910.147 requires an energy control program that includes:
- Written procedures for each piece of equipment.
- Training for authorized and affected workers.
- Periodic inspections of how the procedures are carried out, at least once a year.
In Indonesia, the general duty to control workplace hazards is based on Law No. 1 of 1970 on Occupational Safety (UU No. 1 Tahun 1970 tentang Keselamatan Kerja), and many companies adopt OSHA 29 CFR 1910.147 as the reference for LOTO procedures in their OHS programs.
Conclusion
LOTO is the procedure for isolating, locking, tagging, and verifying every energy source before maintenance. Its core components are safety padlocks, hasps, lockout devices matched to the isolation point (breaker, valve, plug, cable), tags, and a LOTO station, supported by written procedures, training, and periodic inspections.
Avenix supplies BD series LOTO equipment, from safety padlocks, hasps, valve lockouts, electrical lockouts, and cable lockouts to LOTO stations, for factories, shipyards, and industrial facilities in Batam and Bintan. See the options on our LOTO page, or send your list of isolation points and number of workers through Request a Quote and our team will help you put the kit together.
