What is Lock Out Tag Out?

Lock Out Tag Out or LOTO is a popular safety procedure for working on hazardous equipment in various industries and research settings. LOTO ensures that dangerous machines are properly shut off and prior to the completion of maintenance or repair work not able to be started up again. In this safety procedure, before starting any work in a machine the hazardous energy sources are isolated and rendered inoperative. The isolated power sources are locked and a tag is placed on the lock mentioning the related person who placed it. The key is kept with the person at work and it ensures that only he or she can start the machine. So, the accidental startup of the equipment by others is prevented while the work is ongoing in the machine. All energy sources need to be identified, controlled, isolated and locked. In some countries, the lock-out tag-out procedure is mandated by the law.

Purpose of LOTO Safety Procedure

If not isolated properly, machines or equipment during service or maintenance may contain various forms of “hazardous energy” that can cause harm to people in the area. Without the use of proper LOTO safety procedures, the serviced equipment can start-up unexpectedly leading to injuries and even death of the people working. So, A lock-out tag-out plan will prevent

  • Contact with the hazard during working.
  • Unintentional start-up of equipment
  • Un-intentional hazard release
  • Loss of personnel and property
  • Hefty fines for non-compliance
Typical LOTO Devices
Typical LOTO Devices

Steps for Lock-out Tag-out procedure

The first and foremost step in the lock-out tag-out procedure is disconnecting the machine from the energy sources. This process is known as isolation. Lockout tag-out procedures provide steps for isolation which, in general, includes the following tasks:

  • Preparation for the shutdown
  • Identify the energy source(s). Notify employees
  • Isolation of all the energy source(s) including electricity, steam, water, gas, compressed air, and others
  • Release any stored or residual hazardous energy
  • Lock and tag the energy source(s)
  • Checking possibilities of stored energy
  • Verify that the isolation is effective by trying to turn it on in a locked condition.

Safety equipment manufacturers provide a wide range of isolation devices to meet the requirements and to fit various switches, valves, and effectors. All such devices are normally colored in RED to increase visibility.

Companies normally have written work instructions for the LOTO procedures. Such procedures provide the following data:

  • Hazardous Energy types
  • Types of Energy isolating devices
  • Steps and Procedures for LOTO
  • Verification steps for isolation
  • Tools required
  • Responsible person for this process
  • Notified members

Many organizations prepare a lock-out tag-out checklist to ensure that all steps are carried out properly.

Codes and Standards for Lock Out Tag Out (LOTO) Procedure

Various codes and standards provide guidelines for LOTO procedure to ensure safe working. A list of a few such LOTO standards are:

  • CSA Z460 by Canadian Standards Association.
  • 29 CFR 1910.147, OSHA (Occupational Safety and Health Administration), widely followed in the USA and EU regions
  • BS7671:2008 in the UK. However, the lockout tag-out procedure is not enforced in the UK.

OSHA Lock Out Tag Out

As per OSHA lock-out tag-out, any form of energy including electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other sources that may cause serious injury or death due to unexpected start-up should be properly controlled.

Safety from accidental hazardous energy releases can only be ensured by proper lockout/tag-out (LOTO) practices and procedures. In this respect, OSHA lock-out tag-out procedures provide a factsheet known as OSHA Lock-out Tag-out Fact Sheet.  The practices and procedures required to disable equipment and machinery to prevent hazardous energy release are described in this fact sheet. The OSHA standard for The Control of Hazardous Energy (Lockout/Tagout) (29 CFR 1910.147) for general industry outlines specific measures for controlling different types of hazardous energy. The OSHA LOTO standard establishes the employer’s responsibility to protect workers against the release of hazardous energy.

Only the tag-out system is permitted by OSHA instead of lockout systems if the employer can prove the tag-out system to be as effective as a lockout system. 

Lock out Tag Out Kit

Lock-out tag-out kits or LOTO kits are portable bundles of a lock-out tag-out equipment/devices used for multiple different lock-out tag-out procedures for energy isolation.  Such kits contain identification tags, different types of locks, and other required devices (electrical lockout devices, valve lockout devices, safety hasps, etc) that help in isolating the potential release of hazardous energy. All these elements are kept inside a box so that the LOTO process is easily managed. Lockout tag out kits may be general-purpose or specially designed for specific service requirements.

Lock out tag out training

Each worker responsible for working on those machinery must be trained thoroughly to ascertain that they understand and follow the applicable practices of the hazardous energy control procedures. The Directorate of Technical Support and Emergency Management of OSHA provides online interactive training on 29 CFR 1910.147, Lockout/Tagout Interactive Training Program. For more details refer to the following link: Lockout-Tagout Interactive Training Program (osha.gov)

Online Courses on Lock Out Tag Out and Safety

To enhance your knowledge regarding Lock-out Tag-out and safety concern you can try the following online courses:

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Anup Kumar Dey

I am a Mechanical Engineer turned into a Piping Engineer. Currently, I work in a reputed MNC as a Senior Piping Stress Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world.

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