Lockout/Tagout (LOTO): Steps, Padlocks and Lockout Devices
Many serious maintenance accidents happen the same way: someone switches a machine back on, or a valve is opened, while another person is still working inside. Lockout/tagout (LOTO) prevents this. Before work starts, every energy source is isolated and physically locked off, and only the person working on the machine holds the key.
The short answer: isolate every energy source, put your own padlock on each isolation point (with a hasp when several people work on the same equipment), attach a danger tag with your name, release stored energy, and test that the machine cannot start before you touch it. One person, one lock, one key.
Why switching off is not enough
A machine that is "off" can still hurt someone:
- someone else switches it back on, not knowing a person is inside;
- an automatic control or timer restarts it;
- a valve is opened upstream;
- stored energy is released: a spring, a raised load, compressed air, hydraulic pressure, a charged capacitor, or a hot or pressurised line.
An emergency stop button is not isolation. It stops the machine, but the energy is still there and the button can be reset.
The types of energy to isolate
| Energy | Examples | How it is locked out |
|---|---|---|
| Electrical | Motors, panels, sockets | Circuit breaker lockout, plug lockout, isolator switch |
| Mechanical | Moving parts, springs, flywheels | Block, pin or chain, and wait for parts to stop |
| Hydraulic | Presses, lifts, cylinders | Valve lockout, then bleed the pressure |
| Pneumatic | Air tools, actuators | Air source lockout, then vent the line |
| Chemical and process | Pipelines, tanks | Valve lockout on ball, gate or butterfly valves, then drain |
| Thermal | Steam, hot water, hot oil | Valve lockout, then allow to cool |
| Gravity | Raised loads, forks, platforms | Lower, or support with blocks or props |
The LOTO procedure, step by step
- Prepare. Identify every energy source on the equipment, using the machine's written LOTO procedure.
- Notify the operators and everyone affected that the equipment is being shut down.
- Shut down the machine using its normal controls.
- Isolate every energy source at its isolation point: breaker, valve, plug or air supply.
- Lock and tag. Each worker puts their own padlock on each isolation point, with a tag showing their name and the date.
- Release stored energy. Bleed pressure, discharge capacitors, block moving parts, lower loads.
- Verify. Try to start the machine with its normal controls, and test electrical circuits with a tester. Then return the controls to off.
- Work. Only now is the equipment safe to work on.
To restart: remove tools, refit guards, check that everyone is clear, and then each person removes only their own lock.
The equipment
Safety padlocks
LOTO padlocks are used only for lockout, never for lockers or gates. Each worker has their own, with one key, and the locks are keyed differently so no key opens another person's lock. Many companies colour-code padlocks by department or trade: for example, red for electricians and blue for mechanical maintenance. Choose non-conductive (nylon) shackles where locks are used on electrical panels.
Hasps
A lockout hasp takes several padlocks on one isolation point. The equipment cannot be switched on until the last person has removed their lock. It is essential whenever more than one person works on the same machine.
Lockout devices
Many isolation points cannot take a padlock directly. Lockout devices fit over them:
- Circuit breaker lockouts for miniature breakers (MCB, pin-in and pin-out types) and moulded case breakers (MCCB);
- Plug lockouts that enclose the plug so it cannot be connected;
- Valve lockouts for ball valves, gate valves and universal devices for unusual shapes;
- Pneumatic lockouts for air-line connectors;
- Switch and button lockouts for wall switches and emergency stop buttons.
Tags
A danger tag ("DANGER — DO NOT OPERATE") with the worker's name, department and date tells everyone why the equipment is locked and who to ask. A tag alone is a warning, not a lock. Use tags with locks.
Group lock boxes and lockout stations
For large jobs with many isolation points, a supervisor locks every point and places the keys in a group lock box. Each worker then puts their personal lock on the box. A lockout station on the wall keeps padlocks, hasps, tags and devices organised and ready.
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Standards companies follow
Many companies in Egypt base their LOTO programmes on OSHA 29 CFR 1910.147, the American rule for controlling hazardous energy, and on ISO 14118 for preventing unexpected start-up of machinery. Whichever you follow, the essentials are the same: written procedures for each machine, trained workers, personal locks, and regular checks that the procedure is being followed. See the electrical hazards guide, factory PPE and oil and gas PPE.
Questions buyers ask us
Can two people share a padlock?
No. Each person who works on the equipment puts on their own lock and keeps their own key. That is what guarantees nobody can restart the machine while they are inside.
What if someone goes home and leaves their lock on?
Only a supervisor can remove another person's lock, following a written procedure: confirm the worker is not on site, contact them, check the equipment is safe, and record the removal. Bolt cutters are a last resort, never a shortcut.
Do we need LOTO for a quick job?
Yes, if the work puts any part of a person's body where moving parts or energy could reach it, such as clearing a jam, cleaning or adjusting. Quick jobs are when many accidents happen.
Setting up a LOTO programme
A typical starter kit is a padlock for every maintenance worker, hasps, a range of breaker, plug and valve lockouts that fit your equipment, tags and a wall station. Tell us your equipment and team size through For Companies and we will quote within 24 working hours, with bulk prices from 20 pieces.