[Title 29 CFR 1910.147]
[Code of Federal Regulations (annual edition) - July 1, 2002 Edition]
[Title 29 - LABOR]
[Subtitle B - Regulations Relating to Labor (Continued)]
[Chapter Xvii - OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT]
[Part 1910 - OCCUPATIONAL SAFETY AND HEALTH STANDARDS]
[Subpart J - General Environmental Controls]
[Sec. 1910.147 - The control of hazardous energy (lockout/tagout).]
[From the U.S. Government Printing Office]
29LABOR52002-07-012002-07-01falseThe control of hazardous energy (lockout/tagout).1910.147Sec. 1910.147LABORRegulations Relating to Labor (Continued)OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENTOCCUPATIONAL SAFETY AND HEALTH STANDARDSGeneral Environmental Controls
Sec. 1910.147 The control of hazardous energy (lockout/tagout).
(a) Scope, application and purpose--(1) Scope. (i) This standard
covers the servicing and maintenance of machines and equipment in which
energization or start up of the machines or equipment, or release of
stored energy could cause injury to employees. This standard establishes
minimum performance requirements for the control of such hazardous
(ii) This standard does not cover the following:
(A) Construction, agriculture and maritime employment;
(B) Installations under the exclusive control of electric utilities
for the purpose of power generation, transmission and distribution,
including related equipment for communication or metering; and
(C) Exposure to electrical hazards from work on, near, or with
conductors or equipment in electric utilization installations, which is
covered by subpart S of this part; and
(D) Oil and gas well drilling and servicing.
(2) Application. (i) This standard applies to the control of energy
during servicing and/or maintenance of machines and equipment.
(ii) Normal production operations are not covered by this standard
(See subpart 0 of this part). Servicing and/or maintenance which takes
place during normal production operations is covered by this standard
(A) An employee is required to remove or bypass a guard or other
safety device; or
(B) An employee is required to place any part of his or her body
into an area on a machine or piece of equipment where work is actually
performed upon the material being processed (point of operation) or
where an associated danger zone exists during a machine operating cycle.
Note: Exception to paragraph (a)(2)(ii): Minor tool changes and
adjustments, and other minor servicing activities, which take place
during normal production operations, are not covered by this standard if
they are routine, repetitive, and integral to the use of the equipment
for production, provided that the work is performed using alternative
measures which provide effective protection (See subpart 0 of this
(iii) This standard does not apply to the following.
(A) Work on cord and plug connected electric equipment for which
exposure to the hazards of unexpected energization or start up of the
equipment is controlled by the unplugging of the equipment from the
energy source and by the plug being under the exclusive control of the
employee performing the servicing or maintenance.
(B) Hot tap operations involving transmission and distribution
systems for substances such as gas, steam, water or petroleum products
when they are performed on pressurized pipelines, provided that the
employer demonstrates that (1) continuity of service is essential; (2)
shutdown of the system is impractical; and (3) documented procedures are
followed, and special equipment is used which will provide proven
effective protection for employees.
(3) Purpose. (i) This section requires employers to establish a
program and utilize procedures for affixing appropriate lockout devices
or tagout devices to energy isolating devices, and to otherwise disable
machines or equipment to prevent unexpected energization, start-up or
release of stored energy in order to prevent injury to employees.
(ii) When other standards in this part require the use of lockout or
tagout, they shall be used and supplemented by the procedural and
training requirements of this section.
(b) Definitions applicable to this section.
Affected employee. An employee whose job requires him/her to operate
or use a machine or equipment on which servicing or maintenance is being
performed under lockout or tagout, or whose job requires him/her to work
in an area in which such servicing or maintenance is being performed.
Authorized employee. A person who locks out or tags out machines or
equipment in order to perform servicing or maintenance on that machine
or equipment. An affected employee becomes an authorized employee when
that employee's duties include performing servicing or maintenance
covered under this section.
Capable of being locked out. An energy isolating device is capable
of being locked out if it has a hasp or other means of attachment to
which, or through which, a lock can be affixed, or it has a locking
mechanism built into it. Other energy isolating devices are capable of
being locked out, if lockout
can be achieved without the need to dismantle, rebuild, or replace the
energy isolating device or permanently alter its energy control
Energized. Connected to an energy source or containing residual or
Energy isolating device. A mechanical device that physically
prevents the transmission or release of energy, including but not
limited to the following: A manually operated electrical circuit
breaker; a disconnect switch; a manually operated switch by which the
conductors of a circuit can be disconnected from all ungrounded supply
conductors, and, in addition, no pole can be operated independently; a
line valve; a block; and any similar device used to block or isolate
energy. Push buttons, selector switches and other control circuit type
devices are not energy isolating devices.
Energy source. Any source of electrical, mechanical, hydraulic,
pneumatic, chemical, thermal, or other energy.
Hot tap. A procedure used in the repair, maintenance and services
activities which involves welding on a piece of equipment (pipelines,
vessels or tanks) under pressure, in order to install connections or
appurtenances. It is commonly used to replace or add sections of
pipeline without the interruption of service for air, gas, water, steam,
and petrochemical distribution systems.
Lockout. The placement of a lockout device on an energy isolating
device, in accordance with an established procedure, ensuring that the
energy isolating device and the equipment being controlled cannot be
operated until the lockout device is removed.
Lockout device. A device that utilizes a positive means such as a
lock, either key or combination type, to hold an energy isolating device
in a safe position and prevent the energizing of a machine or equipment.
Included are blank flanges and bolted slip blinds.
Normal production operations. The utilization of a machine or
equipment to perform its intended production function.
Servicing and/or maintenance. Workplace activities such as
constructing, installing, setting up, adjusting, inspecting, modifying,
and maintaining and/or servicing machines or equipment. These activities
include lubrication, cleaning or unjamming of machines or equipment and
making adjustments or tool changes, where the employee may be exposed to
the unexpected energization or startup of the equipment or release of
Setting up. Any work performed to prepare a machine or equipment to
perform its normal production operation.
Tagout. The placement of a tagout device on an energy isolating
device, in accordance with an established procedure, to indicate that
the energy isolating device and the equipment being controlled may not
be operated until the tagout device is removed.
Tagout device. A prominent warning device, such as a tag and a means
of attachment, which can be securely fastened to an energy isolating
device in accordance with an established procedure, to indicate that the
energy isolating device and the equipment being controlled may not be
operated until the tagout device is removed.
(c) General--(1) Energy control program. The employer shall
establish a program consisting of energy control procedures, employee
training and periodic inspections to ensure that before any employee
performs any servicing or maintenance on a machine or equipment where
the unexpected energizing, start up or release of stored energy could
occur and cause injury, the machine or equipment shall be isolated from
the energy source, and rendered inoperative.
(2) Lockout/tagout. (i) If an energy isolating device is not capable
of being locked out, the employer's energy control program under
paragraph (c)(1) of this section shall utilize a tagout system.
(ii) If an energy isolating device is capable of being locked out,
the employer's energy control program under paragraph (c)(1) of this
section shall utilize lockout, unless the employer can demonstrate that
the utilization of a tagout system will provide full employee protection
as set forth in paragraph (c)(3) of this section.
(iii) After January 2, 1990, whenever replacement or major repair,
renovation or modification of a machine or equipment is performed, and
whenever new machines or equipment are installed, energy isolating
devices for such machine or equipment shall be designed to accept a
(3) Full employee protection. (i) When a tagout device is used on an
energy isolating device which is capable of being locked out, the tagout
device shall be attached at the same location that the lockout device
would have been attached, and the employer shall demonstrate that the
tagout program will provide a level of safety equivalent to that
obtained by using a lockout program.
(ii) In demonstrating that a level of safety is achieved in the
tagout program which is equivalent to the level of safety obtained by
using a lockout program, the employer shall demonstrate full compliance
with all tagout-related provisions of this standard together with such
additional elements as are necessary to provide the equivalent safety
available from the use of a lockout device. Additional means to be
considered as part of the demonstration of full employee protection
shall include the implementation of additional safety measures such as
the removal of an isolating circuit element, blocking of a controlling
switch, opening of an extra disconnecting device, or the removal of a
valve handle to reduce the likelihood of inadvertent energization.
(4) Energy control procedure. (i) Procedures shall be developed,
documented and utilized for the control of potentially hazardous energy
when employees are engaged in the activities covered by this section.
Note: Exception: The employer need not document the required
procedure for a particular machine or equipment, when all of the
following elements exist: (1) The machine or equipment has no potential
for stored or residual energy or reaccumulation of stored energy after
shut down which could endanger employees; (2) the machine or equipment
has a single energy source which can be readily identified and isolated;
(3) the isolation and locking out of that energy source will completely
deenergize and deactivate the machine or equipment; (4) the machine or
equipment is isolated from that energy source and locked out during
servicing or maintenance; (5) a single lockout device will achieve a
locked-out condition; (6) the lockout device is under the exclusive
control of the authorized employee performing the servicing or
maintenance; (7) the servicing or maintenance does not create hazards
for other employees; and (8) the employer, in utilizing this exception,
has had no accidents involving the unexpected activation or
reenergization of the machine or equipment during servicing or
(ii) The procedures shall clearly and specifically outline the
scope, purpose, authorization, rules, and techniques to be utilized for
the control of hazardous energy, and the means to enforce compliance
including, but not limited to, the following:
(A) A specific statement of the intended use of the procedure;
(B) Specific procedural steps for shutting down, isolating, blocking
and securing machines or equipment to control hazardous energy;
(C) Specific procedural steps for the placement, removal and
transfer of lockout devices or tagout devices and the responsibility for
(D) Specific requirements for testing a machine or equipment to
determine and verify the effectiveness of lockout devices, tagout
devices, and other energy control measures.
(5) Protective materials and hardware. (i) Locks, tags, chains,
wedges, key blocks, adapter pins, self-locking fasteners, or other
hardware shall be provided by the employer for isolating, securing or
blocking of machines or equipment from energy sources.
(ii) Lockout devices and tagout devices shall be singularly
identified; shall be the only devices(s) used for controlling energy;
shall not be used for other purposes; and shall meet the following
(A) Durable. (1) Lockout and tagout devices shall be capable of
withstanding the environment to which they are exposed for the maximum
period of time that exposure is expected.
(2) Tagout devices shall be constructed and printed so that exposure
to weather conditions or wet and damp locations will not cause the tag
to deteriorate or the message on the tag to become illegible.
(3) Tags shall not deteriorate when used in corrosive environments
such as areas where acid and alkali chemicals are handled and stored.
(B) Standardized. Lockout and tagout devices shall be standardized
within the facility in at least one of the following criteria: Color;
shape; or size; and additionally, in the case of tagout devices, print
and format shall be standardized.
(C) Substantial--(1) Lockout devices. Lockout devices shall be
substantial enough to prevent removal without the use of excessive force
or unusual techniques, such as with the use of bolt cutters or other
metal cutting tools.
(2) Tagout devices. Tagout devices, including and their means of
attachment, shall be substantial enough to prevent inadvertent or
accidental removal. Tagout device attachment means shall be of a non-
reusable type, attachable by hand, self-locking, and non-releasable with
a minimum unlocking strength of no less than 50 pounds and having the
general design and basic characteristics of being at least equivalent to
a one-piece, all-environment-tolerant nylon cable tie.
(D) Identifiable. Lockout devices and tagout devices shall indicate
the identity of the employee applying the device(s).
(iii) Tagout devices shall warn against hazardous conditions if the
machine or equipment is energized and shall include a legend such as the
following: Do Not Start, Do Not Open, Do Not Close, Do Not Energize, Do
(6) Periodic inspection. (i) The employer shall conduct a periodic
inspection of the energy control procedure at least annually to ensure
that the procedure and the requirements of this standard are being
(A) The periodic inspection shall be perfomed by an authorized
employee other than the ones(s) utilizing the energy control procedure
(B) The periodic inspection shall be conducted to correct any
deviations or inadequacies identified.
(C) Where lockout is used for energy control, the periodic
inspection shall include a review, between the inspector and each
authorized employee, of that employee's responsibilities under the
energy control procedure being inspected.
(D) Where tagout is used for energy control, the periodic inspection
shall include a review, between the inspector and each authorized and
affected employee, of that employee's responsibilities under the energy
control procedure being inspected, and the elements set forth in
paragraph (c)(7)(ii) of this section.
(ii) The employer shall certify that the periodic inspections have
been performed. The certification shall identify the machine or
equipment on which the energy control procedure was being utilized, the
date of the inspection, the employees included in the inspection, and
the person performing the inspection.
(7) Training and communication. (i) The employer shall provide
training to ensure that the purpose and function of the energy control
program are understood by employees and that the knowledge and skills
required for the safe application, usage, and removal of the energy
controls are acquired by employees. The training shall include the
(A) Each authorized employee shall receive training in the
recognition of applicable hazardous energy sources, the type and
magnitude of the energy available in the workplace, and the methods and
means necessary for energy isolation and control.
(B) Each affected employee shall be instructed in the purpose and
use of the energy control procedure.
(C) All other employees whose work operations are or may be in an
area where energy control procedures may be utilized, shall be
instructed about the procedure, and about the prohibition relating to
attempts to restart or reenergize machines or equipment which are locked
out or tagged out.
(ii) When tagout systems are used, employees shall also be trained
in the following limitations of tags:
(A) Tags are essentially warning devices affixed to energy isolating
devices, and do not provide the physical restraint on those devices that
is provided by a lock.
(B) When a tag is attached to an energy isolating means, it is not
to be removed without authorization of the authorized person responsible
for it, and it is never to be bypassed, ignored, or otherwise defeated.
(C) Tags must be legible and understandable by all authorized
employees, affected employees, and all other employees whose work
operations are or may be in the area, in order to be effective.
(D) Tags and their means of attachment must be made of materials
which will withstand the environmental conditions encountered in the
(E) Tags may evoke a false sense of security, and their meaning
needs to be understood as part of the overall energy control program.
(F) Tags must be securely attached to energy isolating devices so
that they cannot be inadvertently or accidentally detached during use.
(iii) Employee retraining.
(A) Retraining shall be provided for all authorized and affected
employees whenever there is a change in their job assignments, a change
in machines, equipment or processes that present a new hazard, or when
there is a change in the energy control procedures.
(B) Additional retraining shall also be conducted whenever a
periodic inspection under paragraph (c)(6) of this section reveals, or
whenever the employer has reason to believe, that there are deviations
from or inadequacies in the employee's knowledge or use of the energy
(C) The retraining shall reestablish employee proficiency and
introduce new or revised control methods and procedures, as necessary.
(iv) The employer shall certify that employee training has been
accomplished and is being kept up to date. The certification shall
contain each employee's name and dates of training.
(8) Energy isolation. Lockout or tagout shall be performed only
bythe authorized employees who are performing the servicing or
(9) Notification of employees. Affected employees shall be notified
by the employer or authorized employee of the application and removal of
lockout devices or tagout devices. Notification shall be given before
the controls are applied, and after they are removed from the machine or
(d) Application of control. The established procedures for the
application of energy control (the lockout or tagout procedures) shall
cover the following elements and actions and shall be done in the
(1) Preparation for shutdown. Before an authorized or affected
employee turns off a machine or equipment, the authorized employee shall
have knowledge of the type and magnitude of the energy, the hazards of
the energy to be controlled, and the method or means to control the
(2) Machine or equipment shutdown. The machine or equipment shall be
turned off or shut down using the procedures established for the machine
or equipment. An orderly shutdown must be utilized to avoid any
additional or increased hazard(s) to employees as a result of the
(3) Machine or equipment isolation. All energy isolating devices
that are needed to control the energy to the machine or equipment shall
be physically located and operated in such a manner as to isolate the
machine or equipment from the energy source(s).
(4) Lockout or tagout device application. (i) Lockout or tagout
devices shall be affixed to each energy isolating device by authorized
(ii) Lockout devices, where used, shall be affixed in a manner to
that will hold the energy isolating devices in a ``safe'' or ``off''
(iii) Tagout devices, where used, shall be affixed in such a manner
as will clearly indicate that the operation or movement of energy
isolating devices from the ``safe'' or ``off'' position is prohibited.
(A) Where tagout devices are used with energy isolating devices
designed with the capability of being locked, the tag attachment shall
be fastened at the same point at which the lock would have been
(B) Where a tag cannot be affixed directly to the energy isolating
device, the tag shall be located as close as safely possible to the
device, in a position that will be immediately obvious to anyone
attempting to operate the device.
(5) Stored energy. (i) Following the application of lockout or
tagout devices to energy isolating devices, all potentially hazardous
stored or residual energy shall be relieved, disconnected, restrained,
and otherwise rendered safe.
(ii) If there is a possibility of reaccumulation of stored energy to
a hazardous level, verification of isolation shall be continued until
the servicing or maintenance is completed, or until the possibility of
such accumulation no longer exists.
(6) Verification of isolation. Prior to starting work on machines or
equipment that have been locked out or tagged out, the authorized
employee shall verify that isolation and deenergization of the machine
or equipment have been accomplished.
(e) Release from lockout or tagout. Before lockout or tagout devices
are removed and energy is restored to the machine or equipment,
procedures shall be followed and actions taken by the authorized
employee(s) to ensure the following:
(1) The machine or equipment. The work area shall be inspected to
ensure that nonessential items have been removed and to ensure that
machine or equipment components are operationally intact.
(2) Employees. (i) The work area shall be checked to ensure that all
employees have been safely positioned or removed.
(ii) After lockout or tagout devices have been removed and before a
machine or equipment is started, affected employees shall be notified
that the lockout or tagout device(s) have been removed.
(3) Lockout or tagout devices removal. Each lockout or tagout device
shall be removed from each energy isolating device by the employee who
applied the device. Exception to paragraph (e)(3): When the authorized
employee who applied the lockout or tagout device is not available to
remove it, that device may be removed under the direction of the
employer, provided that specific procedures and training for such
removal have been developed, documented and incorporated into the
employer's energy control program. The employer shall demonstrate that
the specific procedure provides equivalent safety to the removal of the
device by the authorized employee who applied it. The specific procedure
shall include at least the following elements:
(i) Verfication by the employer that the authorized employee who
applied the device is not at the facility;
(ii) Making all reasonable efforts to contact the authorized
employee to inform him/her that his/her lockout or tagout device has
been removed; and
(iii) Ensuring that the authorized employee has this knowledge
before he/she resumes work at that facility.
(f) Additional requirements--(1) Testing or positioning of machines,
equipment or components thereof. In situations in which lockout or
tagout devices must be temporarily removed from the energy isolating
device and the machine or equipment energized to test or position the
machine, equipment or component thereof, the following sequence of
actions shall be followed:
(i) Clear the machine or equipment of tools and materials in
accordance with paragraph (e)(1) of this section;
(ii) Remove employees from the machine or equipment area in
accordance with paragraph (e)(2) of this section;
(iii) Remove the lockout or tagout devices as specified in paragraph
(e)(3) of this section;
(iv) Energize and proceed with testing or positioning;
(v) Deenergize all systems and reapply energy control measures in
accordance with paragraph (d) of this section to continue the servicing
(2) Outside personnel (contractors, etc.). (i) Whenever outside
servicing personnel are to be engaged in activities covered by the scope
and application of this standard, the on-site employer and the outside
employer shall inform each other of their respective lockout or tagout
(ii) The on-site employer shall ensure that his/her employees
understand and comply with the restrictions and prohibitions of the
outside employer's energy control program.
(3) Group lockout or tagout. (i) When servicing and/or maintenance
is performed by a crew, craft, department or other group, they shall
utilize a procedure which affords the employees a level of protection
equivalent to that provided by the implementation of a personal lockout
or tagout device.
(ii) Group lockout or tagout devices shall be used in accordance
procedures required by paragraph (c)(4) of this section including, but
not necessarily limited to, the following specific requirements:
(A) Primary responsibility is vested in an authorized employee for a
set number of employees working under the protection of a group lockout
or tagout device (such as an operations lock);
(B) Provision for the authorized employee to ascertain the exposure
status of individual group members with regard to the lockout or tagout
of the machine or equipment and
(C) When more than one crew, craft, department, etc. is involved,
assignment of overall job-associated lockout or tagout control
responsibility to an authorized employee designated to coordinate
affected work forces and ensure continuity of protection; and
(D) Each authorized employee shall affix a personal lockout or
tagout device to the group lockout device, group lockbox, or comparable
mechanism when he or she begins work, and shall remove those devices
when he or she stops working on the machine or equipment being serviced
(4) Shift or personnel changes. Specific procedures shall be
utilized during shift or personnel changes to ensure the continuity of
lockout or tagout protection, including provision for the orderly
transfer of lockout or tagout device protection between off-going and
oncoming employees, to minimize exposure to hazards from the unexpected
energization or start-up of the machine or equipment, or the release of
Note: The following appendix to Sec. 1910.147 services as a non-
mandatory guideline to assist employers and employees in complying with
the requirements of this section, as well as to provide other helpful
information. Nothing in the appendix adds to or detracts from any of the
requirements of this section.
Appendix A to Sec. 1910.147--Typical Minimal Lockout Procedure
The following simple lockout procedure is provided to assist
employers in developing their procedures so they meet the requirements
of this standard. When the energy isolating devices are not lockable,
tagout may be used, provided the employer complies with the provisions
of the standard which require additional training and more rigorous
periodic inspections. When tagout is used and the energy isolating
devices are lockable, the employer must provide full employee protection
(see paragraph (c)(3)) and additional training and more rigorous
periodic inspections are required. For more complex systems, more
comprehensive procedures may need to be developed, documented and
Lockout procedure for
(Name of Company for single procedure or identification of equipment if
multiple procedures are used)
This procedure establishes the minimum requirements for the lockout
of energy isolating devices whenever maintenance or servicing is done on
machines or equipment. It shall be used to ensure that the machine or
equipment is stopped, isolated from all potentially hazardous energy
sources and locked out before employees perform any servicing or
maintenance where the unexpected energization or start-up of the machine
or equipment or release of stored energy could cause injury.
Compliance With This Program
All employees are required to comply with the restrictions and
limitations imposed upon them during the use of lockout. The authorized
employees are required to perform the lockout in accordance with this
procedure. All employees, upon observing a machine or piece of equipment
which is locked out to perform servicing or maintenance shall not
attempt to start, energize or use that machine or equipment.
Type of compliance enforcement to be taken for violation of the above.
Sequence of Lockout
(1) Notify all affected employees that servicing or maintenance is
required on a machine or equipment and that the machine or equipment
must be shut down and locked out to perform the servicing or
Name(s)/Job Title(s) of affected employees and how to notify.
(2) The authorized employee shall refer to the company procedure to
identify the type and magnitude of the energy that the machine or
equipment utilizes, shall understand the hazards of the energy, and
shall know the methods to control the energy.
Type(s) and magnitude(s) of energy, its hazards and the methods to
control the energy.
(3) If the machine or equipment is operating, shut it down by the
normal stopping procedure (depress stop button, open switch, close
Type(s) and location(s) of machine or equipment operating controls.
(4) De-activate the energy isolating device(s) so that the machine
or equipment is isolated from the energy source(s).
Type(s) and location(s) of energy isolating devices.
(5) Lock out the energy isolating device(s) with assigned individual
(6) Stored or residual energy (such as that in capacitors, springs,
elevated machine members, rotating flywheels, hydraulic systems, and
air, gas, steam, or water pressure, etc.) must be dissipated or
restrained by methods such as grounding, repositioning, blocking,
bleeding down, etc.
Type(s) of stored energy--methods to dissipate or restrain.
(7) Ensure that the equipment is disconnected from the energy
source(s) by first checking that no personnel are exposed, then verify
the isolation of the equipment by operating the push button or other
normal operating control(s) or by testing to make certain the equipment
will not operate.
Caution: Return operating control(s) to neutral or ``off'' position
after verifying the isolation of the equipment.
Method of verifying the isolation of the equipment.
(8) The machine or equipment is now locked out.
Restoring Equipment to Service. When the servicing or maintenance is
completed and the machine or equipment is ready to return to normal
operating condition, the following steps shall be taken.
(1) Check the machine or equipment and the immediate area around the
machine or equipment to ensure that nonessential items have been removed
and that the machine or equipment components are operationally intact.
(2) Check the work area to ensure that all employees have been
safely positioned or removed from the area.
(3) Verify that the controls are in neutral.
(4) Remove the lockout devices and reenergize the machine or
Note: The removal of some forms of blocking may require
reenergization of the machine before safe removal.
(5) Notify affected employees that the servicing or maintenance is
completed and the machine or equipment is ready for use.
[54 FR 36687, Sept. 1, 1989, as amended at 54 FR 42498, Oct. 17, 1989;
55 FR 38685, 38686, Sept. 20, 1990]