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Control of Hazardous Energy – LOTO

Overview

What is hazardous energy?

Energy can be defined as the ability to do work. Energy powers the world around us. Everything that surrounds us function because of various types of energy. As vital and beneficial it maybe it can have harmful consequences if not managed properly. Being exposed to any form of energy beyond acceptable limits can have harmful consequences.

Energy can take various forms such as electrical, mechanical, kinetic, potential, hydraulic, chemical, thermal etc.

What are the harmful effects of hazardous energy?

Energy becomes hazardous when the type and form of energy that we are exposed to is more than the safe limit. Different energy forms have varying safe exposure limits. Injuries resulting from exposure to energy can be serious and sometimes fatal. Injuries may include crushing, cutting, lacerating, amputating, electrocution, burns or fracturing body parts, and others.

When can we be exposed to hazardous energy?

The most common instances when people encounter hazardous energies is during the installation, service, maintenance or repair (service) of an equipment / machinery or unit (system). Improperly and inadequately isolated or controlled energy sources can harm personnel who are engaged in the activity.

At times personnel working on a system isolate all the energy streams that flow into the unit but fail to identify, secure (or) control stored energy that is within the system. Stored energy that is within the system can pose a serious threat to personnel who are engaged in the service, maintenance or installation of equipment or systems.

Examples of instances of where employees can be harmed by hazardous energy are:

  • A conveyor system suddenly moves and entangles an employee who is engaged in removing a jam that has occurred.
  • An employee working on a system is electrocuted because of another employee activating a breaker that supplies electrical energy to the system, which is being worked upon.
  • An employee being exposed to a hazardous fluid as a result of an upstream valve being opened by someone who is unaware of the work being carried out downstream

 

What can be done to control hazardous energy?

Through the right systems, procedures & training energy can be managed safely and leveraged to our benefit. Proper energy isolation, lock-out & tag-out procedures safeguard employees from the harmful effects of both main stream and stored energy. It is essential that employees engaged in the maintenance , servicing or installation of equipment/systems be fully aware of the involved hazards and take the necessary precautions to protect themselves , the assets and environment.

The core of safely managing hazardous energy revolves around the following key areas:

  1. Pre-work
    1. Evaluate
      1. Do a thorough evaluation of the system that is going to be worked upon .Define the system boundaries and identify energy streams going into and out of the system boundary.
      2. Identify the isolation points of the energy streams that go into and out of a system.
    2. Notify
      1. Identify all stakeholders and personnel who will be impacted by the shutdown of the system/equipment.
      2. Notify them and obtain all necessary approvals.
    3. Isolation lock-out & tag -out
      1. De-energize the system and make sure that all system controls are at the neutral/zero position.
      2. Isolate the identified energy isolation points identified in step (a). Apply restraining locks on the device such that unauthorized personnel cannot operate it. In addition to this place warning tags on the device.
      3. In case the device cannot be restrained using a lock or tag use alternative methods to safely secure the energy isolation device. A thorough risk assessment is required to be done if alternate methods are used.

  2. Before starting work
    1. Verify system energy isolation by either operating the machine controls or using verification/testing equipment.
    2. Ensure that all stored energy is released or secured. Stored energy can be non-perceptible and equally dangerous.
    3. Ensure that adequate barricades are installed and warning signages are posted.

  3. Work completion: re-energizing the system
    1. Ensure that all the internal/external system connections are operationally intact and there are no compromised sections.
    2. Ensure that all system controls are in the neutral/off position.
    3. Ensure that the area is cleared of all personnel and work equipment.

 

Pre-work Evaluation

It is essential to undertake a pre-work evaluation before working on any piece of equipment or system. The purpose of the pre-work evaluation is to do a thorough assessment of the system that is going to be worked upon and understand the main energy streams that go into and out of the system. This evaluation also serves as a process to identify stored energies that maybe within the system. Furthermore, the pre work evaluation activity identifies and defines how mainstream energy and stored energy of the system can be safety controlled and managed.

The KAUST SOP for Energy Isolation, Lock-Out and Tag-Out provides a form (Hazardous Energy Control Form) that will aid in doing an evaluation in a systematic manner.

It is also essential to notify all affected and involved parties of the work. This is done to ensure that there is no communication gap and that all potential risks associated with the shutdown of the equipment / system are appropriately mitigated and addressed.

Before work starts

  • Verify system energy isolation by either operating the machine controls or using verification/testing equipment.
  • Ensure that all stored energy is either secured and tagged or released. Stored energy can take any form and magnitude.
  • Typical forms of stored energy include thermal energy, potential energy, kinetic energy, electrical energy and hydraulic energy.
  • Ensure that all personnel working on the system has undergone the necessary training and are competent in their line of work.
  • Ensure that adequate barricades are installed and warning signages are posted.

After work is completed

  • Verify that all the internal and external connections of the system are operationally intact and that there are no compromised sections. Verification to be done by a competent person and all involved stakeholders.
  • Once verification is completed and all involved stakeholders concur on the work, kindly ensure that all personnel, tools and equipment are removed from the area and system. The authorized person is to reassess the area for any left back items, tools, material or personnel.
  • Before reenergizing the system ensure that, the system controls are in an off or neutral position. Once this is done remove the locks on the system energy isolation points are re-energize the system as prescribed.
  • The authorized personnel should arrange to shut off the system if something amiss is noticed. Arrangements to deal with any emergencies should also be put in place prior to re-energizing the system or bringing it back online.

FAQ

Is it necessary to do a pre-work assessment?

It is recommended to carry out a pre –work assessment as it serves as the foundation for safely executing a job that poses a risk of exposure to hazardous energy. It is a systematic method of identifying hazardous energies and defining methods to control the same.

What is stored energy? Is it as hazardous as mainstream energy?

It is the energy that is held / stored within an equipment, machinery, or unit even after it has been isolated from all energy/power sources. The stored energy within a system can be in any type and form. Examples of stored energy include a charged capacitor, pressurized hydraulic or pneumatic pipe or hose, compressed spring etc. Stored energy can be as dangerous as mainstream energy and potentially pose a greater risk. At times stored energy is not perceptible making people underestimate the risk.

What if the system’s energy isolation device cannot be locked?

It is always advisable to use lock-out / tag-out to control hazardous energy. Alternative methods can be adopted in case there are practical issues related to executing the work by locking out the energy source. If work needs to be carried out by utilizing alternative methods of energy control then a thorough and complete risk assessment should be completed. The risk assessment should consider all possible scenarios of energy exposure and define the alternative methods being adopted. The alternative methods that are identified to be used must be evaluated for effectiveness prior to application. While evaluating effectiveness of alternative methods the following factors must to be considered:

  • Practicability/justification analysis
  • Risk assessment based on the tasks being performed
  • Industry best practices/methods
  • Architecture/structure
  • Using well-tried components
  • Using well-tried designs
  • Common cause failure
  • Fault tolerance
  • Exclusivity of control
  • Tamper resistance
  • Program to support
  • Procedures in place
  • Periodic checking and testing
  • Review by a qualified person

What if multiple teams and crews are working on one system?

There are different ways in which a group lockout can be achieved. It can either be achieved by having all the crews report to one Authorized Employee who is responsible to lock-out all the energy sources. The other method through which a group lock out can be achieved is by having in place a system through which either all crews put their individual locks or having group lock out hardware in place such as a group lock box. In either case it is the responsibility of the Department Managers to ensure that an effective process is in place when multiple crews work on the same system.

Is it necessary to take a work permit prior to working on any system or equipment?

If the work being undertaken has an activity that falls in the list of activities classified as high risk as per the KAUST work permit program then the appropriate work permit must be obtained. Else, the work can be done after completing a suitable and sufficient risk assessment and the necessary safety precautions have been taken.

Is it necessary to complete a return to service check?

The risk of an accident persists even after the work is completed and the system is being returned to service / brought online. Mishaps can occur if there are compromised sections within the system and the system is re-energized. A return to service check will aid in ensuring that all the key items are checked in a systematic manner and that everything is intact prior to re-energization.

Is it necessary to undergo training on hazardous energy control, lockout & tag –out?

It is crucial that employees engaged in a job that poses a risk of exposure to hazardous energy is completely aware of the risks and the associated safety measures. In this regard it is the Department Manager’s responsibility to ensure that all relevant employees be provided with the necessary training. Training can be completed online through the Salute LMS portal. Kindly contact hse@kaust.edu.sa for more information

Resources

SOP Work Permit SOP Energy Isolation ,Lock-Out and Tag-Out Procedure TBT Energy Isolation ,Lock-Out and Tag-Out Energy control quick reference aid Hazardous Energy Control Forms