LOTO (Lockout Tagout) is one of the most common safety interview questions: what is LOTO, what is its purpose, and where and how is it used? In this video, with a practical demonstration by an electrician, we explain each part of a LOTO kit and how to use it correctly on site.
What is LOTO?
LOTO stands for Lockout Tagout. It is a safety procedure used to isolate (de-energize) electrical or mechanical energy before maintenance or repair work, so that nobody can switch the equipment on while someone is working on it.
Purpose of LOTO
The purpose of LOTO is to let people work safely on equipment. It protects the worker from electric shock or sudden machine movement, and it tells everyone else that work is in progress and the equipment must not be operated.
Before you apply LOTO
- You must have a valid work permit.
- Inform your supervisor.
- Identify the fault and exactly which equipment or line you will work on.
- Check whether supply is coming to that point.
How LOTO is applied: step by step
- Switch off the breaker or isolate the energy source.
- Apply your lock to the isolation point (lockout).
- Fill in and attach the tag (tagout). The tag says DO NOT OPERATE and shows your name, company number or contact number, and remarks about the problem and what has been switched off.
- Keep the key with you. The key must stay with the person who applied the lock, never with someone else.
- After finishing the job, remove only your own lock and tag.
Single lock vs multi-lock hasp
A single lock is used when one person is working. When more than one technician is working on the same line, a multi-lock hasp (for example, one with six holes) is used. Each worker puts their own lock and tag in one of the holes.
Why this matters: if only one lock is used and that technician finishes, opens the lock and switches the breaker back on, another technician who is still working further down the line could get an electric shock or even be killed. With a hasp, the equipment cannot be energized until every worker has removed their own lock.
Also remember: on electrical work, one person should not work alone. At least two people should work together.
Other LOTO devices
- Cable and plug lockout boxes for damaged cables.
- Valve lockouts for mechanical isolation.
- For heavy equipment and machines: switch off the battery isolator, disconnect the battery terminals and lock them, remove the key, and attach a tag so the next person knows work is in progress.
Common LOTO interview questions
- What is LOTO and what does it stand for?
- What is the purpose of LOTO?
- What is the difference between a single lock and a multi-lock hasp?
- What information is written on a LOTO tag?
- Who should keep the key of the lock?
- Can you remove another person’s lock?
Test yourself now: take the LOTO quiz.