the general industry standard 29 CFR 1910.147. This standard covers the servicing
and maintenance of machines and equipment in which their unexpected energization, start up or release
of stored energy could cause injury to employees. Energy may consist of gravitational, hydraulic,
pneumatic, electric, and kinetic.
This booklet is not intended to be totally inclusive of the Occupational Safety and Health Administrations
(OSHAs) standard or does not alter the standard but to give employers a better understanding of the
standard and control procedures. Employers should obtain a copy of the standard and develop their own
site-specific policy for lockout / tagout procedures on machines and equipment. Program guidelines are
listed in Appendix A. of the booklet.
The standard identifies the practices and procedures necessary to shut down and lockout or tagout
machines and equipment, requires that employees receive training in their role in the lockout/tagout
program, and mandates that periodic inspections be conducted to maintain or enhance the energy control
program.
In general, the standard requires that before service or maintenance is performed on machines or
equipment they must be turned off and disconnected from the energy source, and the energy-isolating
device must be either locked or tagged out.
I. Servicing and/or Maintenance Operations
If a servicing activity such as lubricating, cleaning, or unjamming the production equipment, takes place
during production, the employee performing the servicing may be subjected to hazards that are not
encountered as part of the production operation itself. Workers must use a lockout/tagout policy when one
of the following occur:
The employee must either remove or bypass machine guards or other safety devices, resulting in
exposure to hazards at the point of operation;
The employee is required to place part of his/her body in contact with the machine or equipment's
point of operation; or
The employee is required to place any part of his/her body into a danger zone associated with a
machine operating cycle.
In the above situations, the equipment must be deenergized and locks or tags applied to the energy-
isolation devices (circuit breaker, disconnect switch, power switch).
When other servicing operations occur, such as setting up equipment, or making adjustments to machines,
employees performing tasks are required to lock out or tag out if they can be injured by unexpected 3
energization or startup of the equipment. When adjustments must be made with the power on, employers
must provide effective protection when employee make the adjustments.
II. Energy Control Program
This standard requires that the employer establish an energy control program that includes:
(1.) documented energy control procedures,
(2.) an employee training program, and
(3.) periodic inspections of the use of the procedures.
Employers are required to establish a program to ensure that machines and equipment are isolated and
inoperative before any employee performs servicing or maintenance where the unexpected energization,
start up, or release of stored energy could occur and cause injury.
The purpose of the energy control program is to ensure that, whenever the possibility of unexpected
machine or equipment startup or energization exists or the unexpected release of stored energy could injure
a worker during maintenance or servicing, the equipment is isolated from its energy source(s) and rendered
inoperative prior to working on it.
A. Energy Control Procedure
The standard requires that energy control procedures be developed, documented, and used to control
potentially hazardous energy whenever workers perform activities covered by the standard.
Written procedures must identify the information that the authorized employees must know to control
hazardous energy during servicing or maintenance. If this information is the same for various machines or
equipment then a single energy control procedure may be sufficient. If there are other conditions such as
multiple energy sources or different connecting means, then the employer must develop separate energy
controls procedures to protect employees. The energy control procedures must outline the scope, purpose,
authorization, and techniques that will be used to control hazardous energy as well as the means that will
be used to enforce compliance.
At a minimum, the procedures must include, the following elements:
A statement on how the procedures will be used;
The procedural steps needed to shut down, isolate, block, and secure machines/equipment;
The steps designating the safe placement, removal, and transfer of lockout/tagout devices and who
is responsible for them;
The specific requirements for testing machines/equipment and verifying the effectiveness of locks,
tags, and other energy control measures; and
The employer or an authorized employee must notify affected employees before lockout or tagout
devices are applied and after they are removed. 4
Procedures for applying a lockout/tagout device are:
(1.) preparing for shutdown,
(2.) shutdown,
(3.) isolation of machine or equipment from the energy source(s),
(4.) application of the lockout/tagout device(s) to the energy-isolating device(s),
(5.) safely releasing all potentially hazardous stored or residual energy, and
(6.) verifying the isolation of the machine or equipment prior to the start of work.
Before lockout or tagout devices are removed and energy is restored to the machines or equipment, certain
steps must be taken to reenergize equipment after servicing is completed:
(1.) ensuring that machines or equipment components are operationally intact,
(2.) ensuring that all employees are safely positioned or removed from equipment, and
(3.) ensuring that lockout or tagout devices are removed from each energy-isolating device by the
employee who applied the device.
B. Employee Training
The employer must provide effective initial training and retraining as necessary and must certify that such
training has been given to all employees covered by the standard. The certification must contain each
employees name and dates of training. There are three types of employees that need different levels of
training -- authorized, affected, and other. Training must include at least the following:
1. Authorized - employees with the responsibility for implementing the energy control procedures and
performing the servicing or maintenance.
Recognition of applicable hazardous energy sources.
Details about the type and magnitude of the hazardous energy sources present in the workplace.
The methods and means necessary to isolate and control those energy sources.
2. Affected - usually machine operators or users; and other.
Recognize when the control procedure is being used.
Understand the purpose of the procedure and the importance of not attempting to start up or use
the equipment that has been locked or tagged out.
When using tagout, in addition to normal training required for all employees, employees must be trained in
the following limitations of tags:
Tags are essentially warning devices and do not provide the physical restraint of a lock.
Tags must be legible and understandable by all employees. 5
When a tag is attached to an isolating means, it is not to be removed except by the person who
applied it, and it is never to be bypassed, or ignored.
Tags and their attachments must be made of materials that will withstand the environmental
conditions encountered in the workplace.
Tags may evoke a false sense of security. They are only one part of an overall energy control
program.
Tags must be securely attached to the energy-isolating devices so that they cannot be detached
accidentally during use.
All employees must understand that whenever there is a lockout or tagout device in place only the person
who put it on should remove it and to leave it in place and do not try to start locked out or tagged out
machine.
C. Periodic Inspections
A periodic inspection of each procedure, when usage is at least once a year, must be performed at least
annually to assure that the energy control procedures continue to be implemented properly and that the
employees are familiar with their responsibilities under those procedures. The periodic inspection must be
designed to correct any deviations of inadequacies observed. An authorized employee other than the
one(s) using the energy control procedure must perform the inspections. Each inspection must be
documented and corrections made immediately.
III. Energy-Isolating Devices
There are two types of energy-isolating devices: those capable of being locked and those that are not.
When the energy-isolating device cannot be locked out, the employer must use a tagout. The employer
may also modify or replace the device to make it capable of being locked-out.
If the energy-isolating device is lockable, the employer must use locks unless he or she can demonstrate
that the use of tags would provide protection at least as effective as locks and would assure full employee
protection.
Full employee protection includes complying with all tagout-related provisions plus implementing
additional safety measures that can provide the level of safety equivalent to that obtained by using lockout.
This might involve removing and isolating a circuit element, blocking a controlling switch, opening an
extra disconnecting device, or removing a valve handle to reduce the potential for any inadvertent
energization while tags are attached.
Locks, tags, chains, wedges, key block, adapter pins, self-