Lockout/Tagout (LOTO): How and Why?


Dozens of workers are killed and many more are injured every year because they did not de-energize and lock out equipment before working on it. Most of the deaths are electrocutions, but workers are sometimes crushed or have amputations or other injuries. These types of energy need to be controlled: electric, hydraulic, pneumatic, mechanical, heat, and pressurized liquids, vapors, and gasses.


LOTO is way to make sure electricity or other energy is not turned on (or released) while someone is working on machinery. You must de-energize (prevent equipment from starting or moving), lock it out, release stored energy (for instance, bleed air from a pneumatic hose), and test to make sure the energy is off.

Employer should 
Set up a written LOTO program
Train you to use the program

The program should include:
Planning to identify 
Energy source 
Workers who can get hurt
Who will de-energize equipment (and how) 
Keeping track of all involved workers
Telling workers on new shifts about the LOT job
Making sure the equipment is de-energized so it cannot be restarted
Setting and removing LOTO devices
Coordinating with other jobs under way
Releasing stored energy
Returning equipment to service


1.NOTIFICATION: Tell equipment operators and supervisors that the power is being disconnected or isolated.
2.PREPARATION: Check with your supervisor for a written procedure that tells how to shut down and restart the equipment you are working on.
3.SHOUTDOWN: Turn off equipment.
4.ISOLATION: Separate all energy sources using proper isolating devices like manual circuit breakers or disconnect switches. Push buttons or selector switches cannot be the only way to de-energize. Al lot of equipment has more than one type of energy that needs to be isolated.
5.LOTO APPLICATION: Every worker who can be exposed to hazardous energy must be part of LOTO process.

  1. A lockout device is a key or combination lock with a special tag with a workers name. The lock must be attached to an isolating device, circuit breaker, and/or switch to prevent turning on the energy source or equipment or releasing energy.
    A tag out device is a tag and a way to attach it that can withstand at least 50 pounds of force. (Some tags out devices are attached with wire.) Use a tag out device only when you cannot lock out. The tag should have a label or sigh that says that no one can turn on the equipment or remove the energy-isolating device without permission. (OSHA allows tag out devices, but NIOSH, does not recommend tag out only work).
    Each worker at risk should apply an individual lockout/tag out device to each source of hazardous energy so there may be many locks or tags on each device. You must be the only one who has the key or combination for a lockout device you install except in complex lockout/tag out.
    Individual qualified employee control: For minor servicing, maintenance, or inspection of plug-and-cord equipment, you may work without attaching LOTO devices if you unplug the equipment and you always work next to the power plug and control and plug.
    Complex LOTO: A special written plan is needed when a job has more than one of any of these:

    I.Energy source
    VI.Way to isolation energy, or
    VII.Work shift

    One crew member should be in charge of the whole lockout/tag out process. This person should be trained and identified by name in the written plan.

6.Control of stored energy: Release energy by discharging capacitors, removing jacks or chock blocks, or draining hydraulic lines, for instance.
7.Verification: Use testing equipment (such as an electric circuit tester) to make sure equipment has been de-energized.
8.Removed of LOTO devices: Only the worker who puts on a lockout or tag out device should take it off. If someone else must take off the device, he/she must be sure that the person who installed it is not on the site, and must warn the employee when he/she returns.
9.Return to service: When the work is done and the LOTO devices are off, you must test and lock to be sure all tools, mechanical restraints, and electrical devices have been removed before you turn on power. Before you re-energize, you must warn all workers who can operate the equipment and make sure no one else is near it.
10.Temporary release: If the job requiring LOTO is interrupted for testing or positioning equipment, the procedures must start all over.