Lockout/tagout (LOTO) is a program, procedure, work instruction, or safety system program element designed to keep your workers safe when working with machinery and powered equipment.

This article will touch on the following topics:

  • Why is LOTO so important?
  • Is it different in manufacturing, as opposed to other industries?
  • What are the basic components of a LOTO procedure?
  • Are there key or critical components to a LOTO procedure?
  • Employee training and education
  • Inspection and performance management

An Overview of Lockout/Tagout

The best explanation of what LOTO does, in my opinion, comes from OSHA:

Energy sources including electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other sources in machines and equipment... can be hazardous to workers. During the servicing and maintenance of machines and equipment, the unexpected start-up or release of stored energy can result in serious injury or death to workers.

Workers servicing, (installing/removing) or maintaining machines or equipment may be seriously injured or killed if hazardous energy is not properly controlled. Injuries resulting from the failure to control hazardous energy during (work) maintenance activities can be serious or fatal! Injuries may include electrocution, burns, crushing, cutting, lacerating, amputating, or fracturing body parts, and others.

(For related reading, see First Aid for Major Trauma: Crushes, Amputation, Impalement.)

To put it succinctly, when we're talking about LOTO, we're talking about energy, its control, and in this case, the kind of equipment used in manufacturing.

Locking out equipment controls hazards by preventing unexpected energy release. In some cases, these energy releases occur when someone turns the equipment on or off, but it can also happen when energy that is stored in machine's system is released when work (such as maintenance work) is being done on the machine.

When you think of stored energy, you might think of a battery. It's kind of like that, except it's not restricted to electricity. When it comes to manufacturing equipment, the stored energy could be pneumatic, hydraulic, or tension.

Thankfully, we can control for these kinds of energy releases. Imagine servicing a hydraulic system that is under a pressure or a pneumatic system that is still charged with air. If that equipment isn't locked out and you change a pressure hose, it could release a blast of fluid or compressed air. It could also cause the machine to actuate or return to a neutral position, literally moving it from one position to another. Either way, it could lead to serious injury.

With a proper LOTO procedure in place, however, you would release the pressure (de-energize the equipment) and lockout the equipment to make sure it doesn't get re-energized while you're working on it.

Why Lockout/Tagout Is Important

10% of industrial incidents are related to lockout/tagout issues. And because machinery may require the power to be on for some servicing and troubleshooting work, LOTO procedures may be the only protection a worker has.

Lockout/Tagout Standards to Consult

OSHA's 29 CR 1910.333 provides great detail on electrical hazards and LOTO.

In Canada, the comparable standards is CSA Z460-13, Control of Hazardous Energy - Lockout and Other Methods.

Lockout/Tagout Procedures

Lockout refers to the process of isolating energy in a piece of machinery or heavy equipment. It physically locks the system in a safe mode.

Lockouts are secured with the use of a lockout device, which is a mechanical device that is individually locked with a key (not a combination lock).

Tagout is the labeling process that accompanies the lockout procedure. It involves attaching a tag or indicator (usually a standardized label) with the following information:

With very few exceptions, only the authorized individual who locked out the system is permitted to remove the lock and tag. This ensures that the system is not started up without the authorized individual's knowledge.

How Is Lockout/Tagout Different in Manufacturing?

Lockout/tagout processes for manufacturing are the same as they are in other industries. The basic steps to a lockout procedure don't change, and the type of lockout equipment (the locks and tags) used in manufacturing are diverse but not unique.

(Find out How to Build a Lockout/Tagout Policy to Prevent Tragic Outcomes.)

What makes it different, however, is the sheer diversity of manufacturing and the machinery and equipment designed to do the work. The industry ranges from heavy manufacturing where steel is stamped using huge presses to the fine robotics work taking place in the aerospace and computer manufacturing sectors.

With so much complex equipment needing frequent maintenance and inspection, a well-designed lockout program is essential to keep workers in this industry safe.

Designing Your Lockout Program

The National Safety Council's Accident Prevention Manual for Business and Industry, Administration and Programs, 13th Edition (p. 95) lists the following points as basic components of what an energy control (LOTO) program should include:

  • Documented energy control procedures, including the scope, purpose, authorizations, rules, and techniques used to control energy sources and how compliance will be enforced
  • Employee training program
  • Periodic Inspection and performance review of the use of the procedures

The written program should include, at a minimum:

  • A statement on how the procedures will be used
  • The procedural steps needed to shutdown, isolate, block, and secure the machines and equipment
  • The steps that designate the placement, removal, and transfer of lockout devices and who is responsible for them
  • The specific requirements for testing machines and equipment to determine and verify the effectiveness of LOTO and other energy control measures
  • Instructions for how to notify affected employees in the work area when LOTO is applied or removed (this must be done by an authorized employee)

Before the lock and tags are removed and energy is restored to the machine or equipment, these two steps must be taken:

  • Ensuring that the machines or equipment components are operationally intact
  • Ensuring that all employees, including the worker who applied the lockout device, are safely positioned or removed from the equipment

Education and training are absolute must-haves for a working LOTO system – not only for the equipment operators and the maintenance and servicing personnel, but for but all the individuals affected by this aspect of the work (as identified by your hazard analysis).