Hazardous Energy Control
Written by Steve Hudgik
What is hazardous energy control?
Energy is useful, but it is also dangerous. Energy is found in many forms such as electrical, mechanical, pneumatic, hydraulic, thermal and chemical. Dangerous energy can come from electrical power plants or from energy stored in machines.
The unexpected movement or energizing of equipment during servicing and maintenance can cause injury to employees. In many industries nearly 10% of the serious accidents result from the failure to control hazardous energy. That's why hazardous energy control is important.
Hazardous Energy Control - The harmful effects of hazardous energy
When hazardous energy is not properly controlled, workers servicing or maintaining machines and equipment may be seriously injured or killed. Electrocution, burns, crushing, cutting, lacerating, amputating, or fracturing body parts are common injuries resulting from uncontrolled hazardous energy. Here are some actual examples:
- A steam valve automatically opened, burning workers who are repairing a downstream connection in the piping.
- A jammed conveyor suddenly broke free crushing a worker who was working to clear the jam.
- Internal wiring on a machine electrically shorted, shocking the employee who was repairing the machine.
Workers injured on the job from exposure to hazardous energy lose an average of 24 workdays recovering from injuries. No one can ignore hazardous energy control. Craft workers, electricians, operators and engineers all have been injured and killed by the unexpected release of hazardous energy.
How is hazardous energy controlled?
Following OSHA required standard lockout/tagout (LOTO) practices helps keep workers safe from the release of hazardous energy. These practices are provided in the OSHA 1910.147 standard for "The Control of Hazardous Energy (Lockout/Tagout)" which applies to general industry. It requires specific measures that are to be taken for controlling hazardous energy.
Hazardous Energy Control Training
The OSHA LOTO standard requires the employer to protect workers from hazardous energy. As a part of this responsibility employers are required to train each worker to ensure they know, understand, and are able to follow their company's hazardous energy control procedures. The training must include:
- Workers must be trained so that they understand the purpose and function of the energy control program. At the end of the training they must have the knowledge and skills required for the safe application, use, and removal of energy control devices.
- Everyone who is working in an area where energy control procedures are being used must be trained to know about the purpose and use of the energy control procedures. They must also know, understand and comply with the prohibition against attempting to restart or re-energize machines and equipment that is locked out or tagged out.
- All employees who are authorized to lockout machines or equipment, and who perform service and maintenance, must be trained so that they:
- can recognizer hazardous energy sources
- are able identify the type and magnitude of energy
- know how to isolate and/or control that energy
- Training must include the specific procedures and limitations relating to tagout systems, in situations in which tagout is allowed.
- There must be ongoing retraining. Retraining is used to maintain proficiency and to introduce new or changed energy control methods.
Hazardous Energy Control - Printing LOTO Tags, Labels and Signs
LOTO tags need to be tough so that they cannot be damaged or inadvertently pulled off. That means using LOTO tags made with DuraTag tag stock. DuraTag tags are so tough that they don't need a grommet. Just punch a hole and hang your tag. It's fast and easy.
DuraLabel is also the right choice for labels and signs that provide LOTO procedures and safety messages. With DuraLabel you get top quality, the best warranties in the industry, and tough-tested DuraLabel supplies. Call 1-888-326-9244 today for more information about using DuraLabel printers and supplies to stay in compliance with OSHA standards.
Hazardous Energy Control - Procedures for Energy Control
OSHA requires that employers develop, document, and implement procedures for hazardous energy control. The hazardous energy control procedures must outline the scope, purpose, authorization, rules, and techniques that will be used to control hazardous energy, as well as documenting the means that will be used to enforce compliance with the procedures.
For each potential source of hazardous energy the procedures must identify the type and magnitude of the hazardous energy and specify how workers will be protected during servicing or maintenance. Each machine, or the equipment to which the procedure applies, must be clearly identified. The purpose is to ensure that the authorized employee uses the appropriate energy control procedure for the equipment or machine that they'll be working on.
The energy control procedures must provide the sequential steps necessary to shut down, isolate, block, and secure machines or equipment. In addition, the specific sequential steps for placing, removing, and transferring lockout/tagout devices must be provided.
If energy control procedures are the same for a number of machines, then a single energy control procedure may be used. A single energy control procedure may also be used for equipment or machines that can be grouped together in a logical manner.
Another option is to develop a general comprehensive lockout/tagout procedure that is supplemented by checklists or appendices. However, the energy control procedure must be specific enough and clear so that there cannot be any misunderstanding about what is to be done in a specific circumstance. In some instances this will require a unique, specific energy control procedure that applies to a specific servicing or maintenance operation.
Hazardous Energy Control - Tagout, Full Employee Protection
When an employer uses tagout to control hazardous energy, and the machine or equipment is capable of being locked out, the tagout energy control procedures must provide full employee protection that is equivalent to that which would be provided by a lockout program.
Full employee protection is defined as complying with all tagout-related requirements, plus implementing additional safety measures that result in a level of safety that is equivalent to what can be achieved through using lockout procedures. The following are some examples of how this can be achieved:
- Removing and isolating a circuit element
- Blocking a control switch
- Removing a valve handle
- Opening an extra disconnect device
Hazardous Energy Control - Procedures for Deenergizing Machines or Equipment
OSHA requires that the following specific steps be implemented so that all potential sources of hazardous energy are eliminated or controlled during servicing or maintenance of equipment:
- Prepare for shutdown: Before an authorized or affected employee turns off equipment or shuts down a a machine, that employee must know:
- the type and magnitude of the energy
- the hazards associated with the energy
- the method or means that will be used to control the energy
- Shut down the machine or equipment: The machine or equipment must be turned off or shut down using the normal shutdown procedure, such as using the stop or off button. An orderly shutdown must be conducted to avoid additional hazards to employees that might result from a sudden, unexpected deenergization.
Both authorized and affected employees are permitted to shut down equipment and machines. However, to ensure the work will be done safely OSHA requires that only the authorized workers performing the work be permitted to lockout or tagout the equipment.
- Disconnect the energy isolating device(s): All energy isolating devices used to control the energy to the machine or equipment must be physically located and placed in the "off" position, completely disconnecting the machine or equipment from its energy source. Control circuitry does not provide a physical barrier that stops hazardous energy and, therefore, is not an energy isolation device. For example, push buttons, selector switches, and interlocking gates are not energy isolation devices and are not allowed to be considered as substitutes for energy isolation devices.
- Apply the lockout or tagout device(s): Once the equipment or machine's energy isolating device is physically disconnected, the lockout or tagout device is attached ensuring the equipment cannot be reconnected to the energy source.
- Release or block all stored and residual energy: After all lockout or tagout devices have been applied, any potentially hazardous energy that is stored (residual energy) must be relieved, disconnected, restrained, and rendered safe before the work can begin. In addition, if stored energy could accumulate during the work, steps must be taken to prevent accumulation of energy, including verifying the complete isolation of the equipment. Equipment or machines that use hydraulic or pneumatic systems may require that bleed valves be used to relieve hydraulic or compressed air pressure.
- Verify the isolation and deenergization of equipment before starting work: The hazardous energy control procedure must includes steps that verify the equipment is isolated from energy sources and deenergized, before any work can begin. This step could involve attempting to start the equipment, or attempting to get equipment parts to move. The purpose of this verification step is to provide assurance that energy from all power sources has been totally cut off, that residual or stored energy has been blocked, and that it is impossible for the equipment to be inadvertently started.
Verification can also be accomplished using test equipment such as a voltmeter to check electrical circuits for the presence of electricity. Other types of test equipment may be used to check for the presence of other types of energy.
To completely verify that all potentially hazardous energy has been isolated, it may be necessary to use a combination of verification methods. The appropriate verification methods will depend upon the type of equipment involved, the complexity of the system, as well as other site specific factors.
Hazardous Energy Control - Placement, Removal, and Transfer of Lockout/Tagout Devices
The energy control procedures must provide specific information concerning the placement, removal, and transfer of the lockout/tagout devices. Workers must be familiar with, and able to perform the following steps in the appropriate order.
A) Placement of lockout/tagout device(s): The LOTO procedure must specify whether lockout or tagout devices, or a combination of lockout and tagout devices, are to be used.
For some equipment the sequence and placement of energy isolating and lockout devices can be intricate. For example, a procedure may first require using a lockout device to provide the energy isolation necessary for removing fuses. Then the fuses are removed to provide full employee protection with the use of tagout on a machine. In addition, a third energy isolating point, a block may be needed to control incoming hydraulic pressure and the stored pressure in the equipment may need to be relieved.
It is important to verify that all energy isolation points have been identified, isolated, and the appropriate lockout/tagout device(s) has been applied.
B) Removal of lockout/tagout device(s): Once the work has been completed, the hazardous energy control procedures should provide specific steps that need to be completed before the energy isolating devices may be removed and the equipment reenergized. These include:
- Replace all equipment safeguards; conduct an equipment inspection, and remove of all non-essential tools and equipment. This step ensures that workers are not exposed to the hazards resulting from normal operation. A visual inspection is acceptable for smaller and less complex equipment. For large, more complex equipment, checklists or other administrative tools, that ensure safe operation and a thorough inspection, may be necessary.
- Ensure everyone is in a safe location. This step ensures that no one is in a location where they are exposed to the effects of unexpected energization, start up, or the release of hazardous energy when the lock(s) or tag(s) are removed from the energy isolating devices. This step may be accomplished using a visual inspection. However, for larger, more complex operations, warning devices such as horns, bells or buzzers may be necessary. Workers must be trained so that they understand the meaning of warning sounds and signals.
- Remove lockout/tagout device(s). This step may not be performed until the first two steps are complete. Each lockout or tagout device may only be removed by the authorized employee who placed it, unless the authorized employee who placed the device is unavailable to remove it or there is an emergency situation. Under those limited circumstances, the employer may direct the removal of a lockout or tagout device, provided that the energy control program incorporates specific procedures and training for that purpose, including:
- Verifying that the authorized employee is not at the facility.
- Making all reasonable efforts to contact the employee to inform them their device will be removed.
- Ensuring that the authorized employee knows that the device has been removed prior to their resuming work.
- Notify affected employees that servicing and maintenance is completed. This notification informs the affected employees that the work is completed and that it is now safe to operate the equipment.
Transfer of lockout/tagout devices during shift or personnel changes
Many servicing and maintenance operations may extend across one or more workshifts. In such cases it is crucial that energy control procedures and work authorization permits, if used, ensure that all hazardous energy is continuously maintained in a safe, deenergized condition.
Specific procedures must be implemented to ensure lockout or tagout protection is continued for employees during shift or personnel changes. These procedures must address the transfer of lockout/tagout devices between the outgoing and incoming workers, so that those doing the work have exclusive control of the LOTO devices and they can be certain the equipment is always in a safe condition.
Incoming workers must have the opportunity to verify that the equipment has been deenergized. The incoming employee should not have to depend on the actions of another employee, in particular someone who has left the workplace. They need to verify for themselves that the equipment is in a safe condition.
OSHA recognizes that the removal and replacement of the lockout/tagout devices for each shift may be required if the work is complex and involves large numbers of energy isolation devices, large numbers of workers, and multiple shifts. In these situations, an acceptable approach, that is in compliance with OSHA requirements, is to use a work permit system. Each authorized employee then signs on and off the equipment, and walks down the equipment to ensure continued deenergization before beginning work.
Specific Procedures for Testing or Positioning of Machines or Equipment
Temporary removal of locks or tags and reenergization of the machinery or equipment is permitted to allow for testing or repositioning, provided that there are specific procedures that control the sequence of actions to be taken. The procedures must provide maximum safety coverage for employees when equipment must be energized during the course of servicing. The potential for exposure to unsafe conditions is high during these transition periods. To ensure workplace safety, the following sequence must be followed:
- Clear the machines or equipment of tools and materials.
- Have employees leave the area.
- Remove only those lockout or tagout devices that must be removed for the test or repositioning.
- Energize and proceed with testing or positioning.
- Deenergize all systems, isolate the machine or equipment from the energy source, and reapply the lockout or tagout devices.
OSHA permits the removal of lockout/tagout devices and the reenergization of equipment only during the time necessary for the testing or positioning of the equipment, and only when reenergization is the only option available and is necessary for accomplishing the work.