OSHA Directives
STD 1-7.3 - 29 CFR 1910.147, the Control of Hazardous (Lockout/Tagout) - Inspection Procedures and Interpretive Guidance
OSHA Directives - Table of Contents
- Record Type: Instruction
- Directive Number: STD 1-7.3
- Standard Number: 1910.147
- Subject: 29 CFR 1910.147, the Control of Hazardous (Lockout/Tagout) - Inspection Procedures and Interpretive Guidance
- Information Date: 09/11/1990
U.S. Department of Labor Assistant Secretary for
Occupational Safety and Health
Washington, D.C. 20210
OSHA Instruction STD 1-7.3
SEP 11 1990
Directorate of Compliance Programs
SUBJECT: 29 CFR 1910.147, the Control of Hazardous Energy
(Lockout/Tagout)--Inspection Procedures and
Interpretive Guidance
A. Purpose. This instruction establishes policies and provides
clarification to ensure uniform enforcement of the
Lockout/Tagout Standards.
B. Scope. This instruction applies OSHA-wide.
C. References.
1. General Industry Standards, 29 CFR 1910, Subpart O,
Subpart S, and other specific subparts.
2. OSHA Instruction CPL 2.45B, June 15, 1989, the Revised
Field Operations Manual (FOM).
D. Effective Date of Requirements. All requirements of 29 CFR
1910.147 have an effective date of January 2, 1990. The
information collection requirements contained in this
section have been approved by the Office of Management and
Budget (OMB) and listed under OMB control number 1218-0150,
as announced at Federal Register, Volume 54, No. 199,
October 17, 1989.
E. Action. Regional Administrators and Area Directors shall
ensure that the guidelines and interpretive guidance in this
instruction are followed and that compliance officers are
familiar with the contents of the standard.
F. Federal Program Change. This instruction describes a
Federal program change which affects State programs. Each
Regional Administrator shall:
1. Ensure that this change is forwarded to each State
designee.
OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
2. Explain the technical content of this change to the
State designee as requested.
3. Ensure that State designees acknowledge receipt of this
Federal program change in writing, within 30 days of
notification, to the Regional Administrator. This
acknowledgment should include the State's intention to
follow the inspection guidelines described in this
instruction, or a description of the State's
alternative guidelines which are "at least as
effective" as the Federal guidelines.
a. If a State intends to follow the revised
inspection guidelines described in this
instruction, the State must submit either a
revised version of this instruction, adapted as
appropriate to reference State law, regulations
and administrative structure, or a cover sheet
describing how references in this instruction
correspond to the State's structure. The State's
acknowledgment letter may fulfill the plan
supplement requirement if the appropriate
documentation is provided.
b. Any alternative State inspection guidelines must
be submitted as a State plan supplement within 6
months. If the State adopts an alternative to
Federal guidelines, the State's submission must
identify and provide a rationale for all
substantial differences from Federal guidelines in
order for OSHA to judge whether a different State
guideline is as effective as a comparable Federal
guideline.
4. After Regional review of the State plan supplement and
resolution of any comments thereon, forward the State
submission to the National Office in accordance with
established procedures. The Regional Administrator
shall provide a judgment on the relative effectiveness
of each substantial difference in the State plan change
and an overall assessment thereof with a recommendation
for approval or disapproval by the Assistant Secretary.
5. Review policies, instructions and guidelines issued by
the State to determine that this change has been
communicated to State personnel.
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
G. Background. The Standard for Control of Hazardous Energy
(Lockout/Tagout), 29 CFR 1910.147, was promulgated on
September 1, 1989, at Federal Register, Volume 54, No. 169
(pages 36644-36696), and was effective on January 2, 1990,
as announced at Federal Register, Volume 54, No. 213,
November 6, 1989 (page 46610). Previously existing section
29 CFR 1910.147 was redesignated as 29 CFR 1910.150, Sources
of Standards.
1. Since the inception of its enforcement program, OSHA
has relied on the "General Duty Clause" (Section
5(a)(1) of the OSH Act) to ensure that employers
safeguarded their maintenance and service employees
through the use of lockout/tagout from the hazards
involving the unintentional release of hazardous
energy. Such violations reached a level so significant
that the development and promulgation of a
lockout/tagout standard was required.
2. The new rule addresses practices and procedures that
are necessary to disable machinery or equipment and to
prevent the release of potentially hazardous energy
while maintenance and servicing activities are being
performed.
3. The lockout/tagout provisions of this standard are for
the protection of general industry workers while
performing servicing and maintenance functions and
augment the safeguards specified at Subparts O, S, and
other applicable portions of 29 CFR 1910.
H. Inspection Guidelines. The standard incorporates
performance requirements which allow employers flexibility
in developing lockout/tagout programs suitable for their
particular facilities.
1. The compliance officer shall determine whether
servicing and maintenance operations are performed by
the employees. If so, the compliance officer shall
further determine whether the servicing and maintenance
operations are covered by 29 CFR 1910.147 or by the
requirements or employee safeguarding specified by
other standards as discussed in I.1.
2. Evaluations of compliance with 29 CFR 1910.147 shall be
conducted during all general industry inspections
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
within the scope of the standard in accordance with the
FOM, Chapter III, D.7. and 8., Additional Information
to Supplement Records Review. The review of records
shall include special attention to injuries related to
maintenance and servicing operations.
3. The compliance officer shall evaluate the employer's
compliance with the specific requirements of the
standard. The following guidance provides a general
framework to assist the compliance officer during
inspections:
a. Ask the employer for any hazard analysis or other
basis on which the program related to the standard
was developed. Although this is not a specific
requirement of the standard, such information,
when provided, will aid in determining the
adequacy of the program. It should be noted that
the absence of a hazard analysis does not indicate
non-compliance with the standard.
b. Ask the employer for the documentation including:
procedures for the control of hazardous energy
including shutdown, equipment isolation,
lockout/tagout application, release of stored
energy, verification of isolation; certification
of periodic inspections; and certification of
training. The documented procedure must identify
the specific types of energy to be controlled and,
in instances where a common procedure is to be
used, the specific equipment covered by the common
procedure must be identified at least by type and
location. The identification of the energy to be
controlled may be by magnitude and type of energy.
Note the exception to documentation requirements
at paragraph 1910.147(c)(4)(i), "Note". The
employer need not document the required procedure
for a particular machine or equipment when all
eight(8) elements listed in the "Note" exist.
c. Evaluate the employer's training programs for
"authorized", "affected", and "other" employees.
Interview a representative sampling of selected
employees as a part of this evaluation (29 CFR
1910.147 (c)(7)(i)).
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
(1) Verify that the training of authorized
employees includes:
(a) Recognition of hazardous energy;
(b) Type and magnitude of energy found in
the workplace;
(c) The means and methods of isolating
and/or controlling energy; and
(d) The means of verification of effective
energy control, and the purpose of the
procedures to be used.
(2) Verify that affected employees have been
instructed in the purpose and use of the
energy control procedures.
(3) Verify that all other employees who may be
affected by the energy control procedures are
instructed about the procedure and the
prohibition relating to attempts to restart
or reenergize such machines or equipment.
(4) When the employer's procedures permit the
use of tagout, the training of authorized,
affected, and other employees shall include
the provisions of 29 CFR 1910.147(c)(7)(ii)
and (d)(4)(iii).
d. Evaluate the employer's manner of enforcing the
program (29 CFR 1910.147 (c)(4)(ii)).
4. In the event that deficiencies are identified by
following the guidelines in H.3. of this instruction,
the compliance officer shall evaluate the employer's
compliance with specific requirements of the standard,
with particular attention to the interpretive guidance
provided in section I. and to the following:
a. Evaluate compliance with the requirements for
periodic inspection of procedures.
b. Ensure that the person performing the periodic
inspection is an authorized employee other than
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Directorate of Compliance Programs
the one(s) utilizing the procedure being
inspected.
c. Evaluate compliance with retraining requirements
which result from the periodic inspection of
procedures and practices, or from changes in
equipment/processes.
d. Evaluate the employer's procedures for assessment,
and correction of deviations of inadequacies
identified during periodic inspections of the
energy control procedure.
e. Identify the procedures for release from
lockout/tagout, including:
(1) Replacement of safeguards, machine or
equipment inspection, and removal of
non-essential tools and equipment;
(2) Safe positioning of employees;
(3) Removal of lockout/tagout device(s); and
(4) Notification of affected employees that
servicing and maintenance is completed.
f. Ensure that when group lockout or tagout is used,
it affords a level of protection equivalent to
individual lockout or tagout as amplified in I.7.
through I.9. of this instruction.
5. The lockout/tagout standard is a performance standard;
therefore, additional guidance is provided in Appendix
C of this instruction to assist in effective
implementation by employers and for uniform enforcement
by OSHA field staff.
I. Interpretive Guidance. The following guidance relative to
specific provisions of 29 CFR 1910.147 is provided to assist
compliance officers in conducting inspections where the
standard may be applicable:
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
1. Scope of the Standard.
a. The standard as specified in 29 CFR 1910.147(b),
applies to any source of mechanical, hydraulic,
pneumatic, chemical, thermal, or other energy.
(1) The standard applies to piping systems, and
requires, at 29 CFR 1910.147(d)(5), that all
potentially hazardous stored or residual
energy be relieved, disconnected, restrained,
and otherwise rendered safe. If there is a
possibility of reaccumulation of stored
energy to a hazardous level, continued
monitoring shall be performed while a
potential hazard exists.
(2) The standard also applies to high intensity
electromagnetic fields regulated at 29 CFR
1910.97, nonionizing radiation. Such
electromagnetic devices shall be deenergized
and held off whenever workers are present
within a high intensity ambient field.
(3) Servicing/maintenance of fire alarm and
extinguishing systems and their components,
upon which other employees are dependent for
fire safety, are not required to meet the
requirements of this standard if the workers
performing servicing/maintenance upon fire
extinguishing systems are protected from
hazards related to the unexpected release of
hazardous energy by appropriate alternative
measures. (See 29 CFR 1910, Subpart L.)
b. The standard does not apply to servicing and
maintenance when employees are not exposed to the
unexpected released of hazardous energy.
c. Safeguarding workers from the hazards of
contacting electrically live parts (exposure to
electric current) continues to be regulated at
Subpart S.
d. Servicing and maintenance functions conducted
during normal production operations are not
regulated at 29 CFR 1910.147 if the safeguarding
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OSHA Instruction STD 1-7.3
SEP 11 1990
Directorate of Compliance Programs
provisions of Subpart O or other applicable
portions of 29 CFR 1910 prevent worker exposure to
hazards created by the unexpected energization or
start-up of the machine or equipment. However,
lockout/tagout procedures are required if the
production safeguards are rendered ineffective
while an employee is exposed to hazardous portions
of the machines or equipment.
e. Generally, activities such as lubrication,
cleaning or unjamming, servicing of machines or
equipment, and making adjustments or tool changes,
where the employee may be exposed to the
UNEXPECTED energization or start-up of the
equipment or release of hazardous energy, are
covered by this standard. However, 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 equipment for production,
and if work is performed using alternative
protective measures which provide effective
employee protection. Thus, lockout or tagout is
not required by this standard if the alternative
protective measures enable the servicing employee
to clean or unjam, or otherwise service the
machine without being exposed to unexpected
energization or activation of the equipment, or
the release of stored energy.
NOTE: Appendix C, section A, provides further
guidance in this area.
f. The exclusion of plug and cord connected electric
equipment, at 29 CFR 1910.147(a)(2)(iii)(A),
applies only when the equipment is unplugged and
the plug is under the exclusive control of the
employee performing the servicing and/or
maintenance.
(1) The plug is under the exclusive control of
the employee if it is physically in the
possession of the employee, or in arm's reach
and in line of sight of the employee, or if
the employee has affixed a lockout/tagout
device on the plug.
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
(2) The company lockout/tagout procedures
required by the standard at 29 CFR
1910.147(c)(4) shall specify the acceptable
procedure for handling cord and plug
connected equipment.
2. Procedures.
a. The employer must develop and document procedures
and techniques to be used for the control of
hazardous energy. The standard, at 29 CFR
1910.147(c)(4)(i) "Note," identifies eight (8)
conditions that must exist in order to excuse the
employer's obligation to maintain a written
procedure for a specific machine or piece of
equipment.
b. 29 CFR 1910.147(d)(3) and (d)(5) provide that
energy isolation be a mandatory part of employer's
control procedure where either a lockout system or
a tagout system is used.
c. Similar machines and/or equipment (such as those
using the same type and magnitude of energy and
the same or similar types of controls) can be
covered with a single written procedure.
3. Lockout vs. Tagout.
a. OSHA has determined that lockout is a surer means
of ensuring deenergization of equipment than
tagout, and that it is the preferred method.
b. 29 CFR 1910.147(c)(3)(ii) provides that: When
using a tagout program in those instances where
the equipment is capable of being locked out, the
employer shall demonstrate that the tagout program
will provide a level of safety equivalent to the
obtained when using a lockout program. Additional
means beyond those necessary for lockout are
required. (Additional means include: additional
safety measures such as the removal of an
isolating circuit element, blocking of a
controlling switch, opening of an extra
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Directorate of Compliance Programs
disconnecting device, or the removal of a valve
handle to reduce the likelihood of inadvertent
energization.)
c. 29 CFR 1910.147(c)(4)(ii) provides that: Where
lockout/tagout programs are used, the employer is
required to implement an effective means of
enforcing the program.
d. 29 CFR 1910.147(c)(7)(ii)(A-F) provide that:
Additional training of authorized, affected and
other employees is required when tagout programs
are used.
e. 29 CFR 1910.147(c)(5)(ii)(A) requires that lockout
and tagout devices be capable of withstanding the
environment to which they are exposed. Devices
which are not exposed to harsh environments need
not be capable of withstanding such exposure.
f. 29 CFR 1910.147(c)(5)(ii)(C)(2) requires that
tagout devices having reusable, non-locking,
easily detachable means of attachment (such as
string, cord, or adhesive) are not permitted.
4. Employees and Training.
a. The standard recognized three types of employees:
(1)"authorized" and (2)"affected", defined in
1910.147 (b), and (3)"other", defined in
1910.147(c)(7)(ii)(C). Different levels of
training are required based upon the respective
roles of employees in the control of energy and
the knowledge which they must possess to
accomplish their tasks safely and to ensure the
safety of fellow workers as related to the
lockout/tagout procedures (1910.147(c)(7)(i)).
b. Employees who exclusively perform functions
related to normal production operations, and who
perform servicing and/or maintenance under the
protection of normal machine safeguarding, need
only be trained as "affected" (rather than
"authorized") employees even if tagout procedures
are used. (See, I.1.d. and I.1.e. of this
instruction.)
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Directorate of Compliance Programs
c. The employer's training program must cover, at a
minimum, the following three areas: energy control
program, elements of energy control procedures
relevant to employee duties, and the pertinent
requirements of the standard (1910.147(c)(7) and
(d) through (f)).
d. The employer must provide:
(1) Effective initial training;
(2) Effective retraining as needed; and
(3) Certification of training. The certification
shall contain each employee's name and dates
of training (1910.147(c)(7)iv)).
e. Retraining of authorized and affected employees is
required:
(1) Whenever there is a change in employee job
assignments;
(2) Whenever a new hazard is introduced due to a
change in machines, equipment or process;
(3) Whenever there is a change in the energy
control procedures; or
(4) Whenever a periodic inspection by the
employer reveals inadequacies in the company
procedures or in the knowledge of the
employees.
5. Periodic Inspection by the Employer
a. At least annually, the employer shall ensure that
an authorized employee other than the one(s)
utilizing the energy control procedure being
inspected, is required to inspect and verify the
effectiveness of the company energy control
procedures. These inspections shall at least
provide for a demonstration of the procedures and
may be implemented through random audits and
planned visual observations. These inspections
are intended to ensure that the energy control
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SEP 11 1990
Directorate of Compliance Programs
procedures are being properly implemented and to
provide an essential check on the continued
utilization of the procedures (29 CFR
1910.147(c)(6)(i)).
(1) When lockout is used, the employer's
inspection shall include a review of the
responsibilities of each authorized employee
implementing the procedure with that
employee. Group meetings between the
authorized employee who is performing the
inspection and all authorized employees who
implement the procedure would constitute
compliance with this requirement.
(2) When tagout is used, the employer shall
conduct this review with each affected and
authorized employee.
(3) Energy control procedures used less
frequently than once a year need be inspected
only when used.
b. The periodic inspection must provide for and
ensure effective correction of identified
deficiencies (29 CFR 1910.147(c)(6)(i)(B)).
c. The employer is required to certify that the
prescribed periodic inspections have been
performed (29 CFR 1910.147(c)(6)(ii)).
6. Equipment Testing or Positioning. Under 29 CFR
1910.147(f)(1), OSHA allows the temporary removal of
lockout or tagout devices and the reenergization of the
machine or equipment ONLY during the limited time
necessary for the testing or positioning of machines,
equipment or components. After the completion of the
temporary reenergization, the authorized employees
shall again deenergize the equipment and resume
lockout/tagout procedures.
7. Group Lockout/Tagout. Group lockout/tagout procedures
shall be tailored to the specific industrial operation
and may be unique in the manner that employee
protection from the release of hazardous energy is
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OSHA Instruction STD 1-7.3
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Directorate of Compliance Programs
achieved. Irrespective of the situation, the
requirements of this generic standard specify that each
employee performing maintenance or servicing activities
shall be in control of hazardous energy during his/her
period of exposure.
a. Group operations normally require that a
lockout/tagout program be implemented which
ensures that each authorized employee is protected
from the unexpected release of hazardous energy by
his/her personal lockout/tagout device(s). No
employee may affix the personal lockout/tagout
device of another employee. Various group
lockout/tagout procedures discussed in Appendix C
provide for each authorized employee's use of
his/her personal lockout/tagout device(s).
b. One of the most difficult problems addressed by
the standard involves the servicing and
maintenance of complex equipment. Such equipment
is frequently used in the petrochemical and
chemical industries. Acceptable group
lockout/tagout procedures for complex equipment
are discussed further at Appendix C.
8. Compliance with Group Lockout/Tagout. These operations
shall, at a minimum, provide for the following:
a. Before the machine or equipment is shut down, each
authorized employee who is to be involved during
the servicing/maintenance operation shall be made
aware by the employer of the type, magnitude, and
hazards related to the energy to be controlled and
of the method or means to control the energy. In
the event that the machine or equipment is already
shut down, the authorized employee shall be made
aware of these elements before beginning his/her
work (29 CFR 1910.147(d)(1)). Verification shall
be performed as noted at I.8.f. of this
instruction.
b. An orderly shutdown of the machine or equipment
shall be conducted which conforms to the
documented company procedure and which will not
create hazards (29 CFR 1910.147(d)(2)).
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c. All energy isolating devices needed to isolate the
machine or equipment shall be effectively
positioned and/or installed (29 CFR 1910.147
(d)(3)).
d. The authorized employee(s) performing the
servicing or maintenance (following the company
procedure) shall personally affix a lock or tag
upon each energy isolating device (29 CFR
1910.147(d)(4)(i). The company procedure must
ensure that no employee affixes a personal
lockout/tagout device for another employee.
(1) A single lock upon each energy isolating
device, together with the use of a lockbox
for retention of the keys and to which each
authorized employee affixes his/her personal
lock or tag, also satisfies the requirement
(29 CFR 1910.147(f)(3)(i)).
(2) Locks shall be affixed in a manner that will
hold the energy isolating device in a safe
(off) position (29 CFR 1910.147(d)(4)(ii)).
(3) Tagout devices, where used, shall be affixed
at the same location as would a lock if such
fittings are provided, or shall be affixed in
a manner that will clearly indicate that
movement of the isolating device is
prohibited (29 CFR 1910.147(d)(4)(iii)).
e. Following the application of locks or tags, all
potentially hazardous stored energy or residual
energy shall be relieved, disconnected,
restrained, and otherwise rendered safe (29 CFR
1910.147(d)(5)(i)).
(1) Verification of energy isolation shall be
monitored as frequently as necessary if there
is a possibility of reaccumulation of stored
energy (29 CFR 1910.147(d)(5)(ii)).
(2) Monitoring may be accomplished, for example,
by observation or with the aid of a
monitoring device which will sound an alarm
if a hazardous energy level is being
approached.
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f. Authorized employees shall verify that isolation
and deenergization have been effectively
accomplished before starting servicing/maintenance
work. Verification is also necessary by each
group of workers before starting work at shift
changes.
g. Release from lockout/tagout shall be accomplished
in compliance with the requirements at 29 CFR
1910.147(e).
(1) The machine or equipment area shall be
cleared of nonessential items to prevent
malfunctions which could result in employee
injuries 29 CFR 1910.147(e)(1)).
(2) The authorized employees shall remove their
respective locks or tags from the energy
isolating devices or from the group
lock-box(s) following the procedure
established by the company
(29 CFR 1910.147(e)(3)).
(3) In all instances, the company procedure must
provide a system which identifies each
authorized employee involved in the
servicing/maintenance operation.
(4) Before reenergization, all employees in the
machine or equipment area shall be safely
positioned or moved from the area, and the
affected employees shall be notified that the
lockout/tagout devices have been removed (29
CFR 1910.147(e)(2)).
h. During all group lockout/tagout operations where
the release of hazardous energy is possible, each
authorized employee performing servicing or
maintenance shall be protected by his/her personal
lockout or tagout device and by the company
procedure. As described at Appendix C, B.1.g., a
master tag is a personal tagout device if each
employee personally signs on and signs off on it
and if the tag clearly identifies each authorized
employee who is being protected by it.
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9. Compliance of Outside Personnel. Outside servicing and
maintenance personnel (contractors, etc.) engaged in
activities regulated under 29 CFR 1910.147 are subject
to the requirements of that standard.
a. The CSHO shall verify that the outside employer
and the on-site employer have exchanged
information regarding the lockout/tagout energy
control procedures used by each employer's workers
(29 CFR 1910.147(f)(2)(i)).
b. The CSHO shall verify that the on-site employer
has effectively informed his/her personnel of the
restrictions and prohibitions associated with the
outside employer's energy control procedures (29
CFR 1910.147(f)(2)(ii)).
c. When an outside employer is engaged in servicing
and maintenance activities within an on-site
employer's facility and if that contractor's
activities are subject to the requirements of 29
CFR 1910.147, the CSHO shall coordinate with the
Area Director to obtain permission to initiate an
independent inspection of the outside contractor's
activities.
10. Appendix B contains an example of a functional flow
diagram to implement safe lockout/tagout procedures.
This flow diagram is presented solely as an aid and
does not constitute the exclusive or definitive means
of complying with the standard in any particular
situation.
J. Classification of Violations.
1. A deficiency in the employer's energy control program
and/or procedure that could contribute to a potential
exposure capable of producing serious physical harm or
death shall be cited as a serious violation.
2. The failure to train "authorized", "affected", and
"other" employees as required for their respective
classifications should normally be cited as a serious
violation.
3. Paperwork deficiencies in lockout/tagout programs where
effective lockout/tagout work procedures are in place
shall be cited as other-than-serious.
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K. Evaluation. In keeping with agency policy, each Region
shall evaluate the effectiveness of the guidance in this
instruction annually. Each Regional Administrator shall
submit a written evaluation report to the Directorate of
Compliance Programs within 30 days of the close of the
fiscal year.
Gerard F. Scannell
Assistant Secretary
DISTRIBUTION: National, Regional, and Area Offices
All Compliance Officers
State Designees
NIOSH Regional Program Directors
7(c)(1) Consultation Project Managers
OSHA Training Institute
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Appendix A
The following listing indicates a number of OSHA standards which
currently impose lockout/tagout related requirements. The list
does not necessarily include all lockout/tagout related OSHA 29
CFR 1910 standards.
Powered Industrial Trucks
1910.178(q)(4)
Overhead and Gantry Cranes
1910.179(g)(5)(i), (ii), (iii)
1910.179(1)(2)(i)(c), (d)
Derricks
1910.181(f)(2)(i)(c), (d)
Woodworking Machinery
1910.213(a)(10)
1910.213(b)(5)
Mechanical Power Presses
1910.217(b)(8)(i)
1910.217(d)(9)(iv)
Forging Machines
1910.218(a)(3)(iii), (iv)
1910.218(d)(2)
1910.218(e)(1)(ii), (iii)
1910.218(f)(1)(i), (ii), (iii)
1910.218(f)(2)(i), (ii)
1910.218(h)(2), (5)
1910.218(i)(1), (2)
1910.218(j)(1)
Welding, Cutting and Brazing
1910.252(c)(1)(i)
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Pulp, Paper and Paperboard Mills
1910.261(b)(4)
1910.261(f)(6)(i)
1910.261(g)(15)(i)
1910.261(g)(19)(iii)
1910.261(j)(4)(iii)
1910.261(j)(5)(iii)
1910.261(k)(2)(ii)
Textiles
1910.262(c)(1)
1910.262(n)(2)
1910.262(p)(1)
1910.262(q)(2)
Bakery Equipment
1910.263(l)(3)(iii)(b), 1910.263(l)(8)(iii)
Sawmills
1910.265(c)(12)(v), 1910.265(c)(13), 1910.265(c)(26)(v)
Grain Handling
1910.272(e)(1)(ii)
1910.272(g)(1)(ii)
1910.272(l)(4)
Electrical
1910.305(j)(4)(ii)(A), 1910.305(j)(4)(ii)(c)(1)
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OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
Appendix B
This flow diagram does not constitute the exclusive or definitive
means of complying with the standard in any particular situation
and is presented solely as an aid.
EXAMPLE - FUNCTIONAL FLOW DIAGRAM FOR IMPLEMENTATION OF
LOCKOUT/TAGOUT REQUIREMENTS
___________________________________________________________________
CONDUCT MACHINE/PROCESS DEVELOP DOCUMENTED
HAZARD ANALYSIS _________
LOCKOUT/TAGOUT PROCEDURE
^ |
| V
____________________| DEVELOP TRAINING PROGRAM
| __________________________ |_________________________
| V V V
|PROVIDE TRAINING TO PROVIDE DETAILED TRAINING PROVIDE TRAINING TO
| AFFECTED EMPLOYEES TO AUTHORIZED EMPLOYEES ALL OTHER EMPLOYEES
| |
| V
| ASSIGN MAINT./SERVICE
| TASK TO
| AUTHORIZED EMPLOYEES
| |
| V
| ___________________________ AND
| | |
| V V
| CONSULT COMPANY NOTIFY AFFECTED
| PROCEDURES DOCUMENT EMPLOYEE(S) OF
| | MAINT./SERVICE OPS
| |
| | IDENTIFY
| | ENERGY ISOLATING DEVICES
| |
| | IDENTIFY & OBTAIN
| |_______________
LOCKOUT/TAGOUT
| DEVICES
| |
| V __________________________
| ___________AND/OR__________ |
| | | |
| V V |
| DEACTIVATE & DEACTIVATE & |
| TAGOUT LOCKOUT |
| |_________________________| |
| | |
| V |
| VERIFY HAZARDOUS |
| ENERGY CONTROLLED |
| | |
|__
HAZARDOUS ENERGY __________ OR |
NOT CONTROLLED | |
V |
PERFORM TASK |
| |
V |
RETRIEVE TOOLS & EQUIPMENT |
| |
V |
VERIFY PERSONNEL |
CLEAR AND ACCOUNTED FOR |
| |
V |
REMOVE LOCKOUT/TAGOUT |
DEVICES |
| |
V |
NOTIFY AFFECTED |
EMPLOYEES |
| |
V |
RETURN CUSTODY OF RESTORE POWER & PROBLEM IDENTIFIED
EQUIPMENT __________ VERIFY OPS ___________
TO AFFECTED EMPLOYEE(S)
B-1
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
Appendix C
This appendix provide guidelines to assist the compliance officer
during evaluations of employer operations.
A. Normal Production Operations. The lockout/tagout standard,
29 CFR 1910.147, addresses the safety of employees engaged
in servicing and maintenance activities in general industry
workplaces. The standard complements the requirements for
machine and process operator safety prescribed by the
various general industry standards in 29 CFR Part 1910.
Subpart O of 29 CFR 1910 provides the principal, though not
exclusive, machine guarding requirements.
1. Safeguarding of servicing and maintenance workers can
be ensured either by:
a. Effective machine safeguarding in compliance with
Subpart O, or
b. Compliance with 29 CFR 1910.147 in situations
where the normal production operations safeguards
are rendered ineffective or do not protect the
servicing/maintenance worker.
2. Activities which are routine, repetitive, and integral
to the use of equipment for production are not covered
by this standard if alternative measures provide
effective worker protection from hazards associated
with unexpected energization. Compliance with the
machine guarding requirements of Subpart O is an
example of such alternative measures. In addition,
supplemental personal protective equipment may be
necessary during a servicing or maintenance operation
when a toxic substance is to be isolated. Under such
circumstances, the requirements of applicable
standards, such as 29 CFR 1910.134 and Subpart Z, also
must be met.
3. An employer who requires employees to perform routine
maintenance and/or servicing while a machine or process
is operating in the production mode, must provide
employee safeguarding under the applicable requirements
of Subpart O. (Ref. 29 CFR 1910.212(a)(1)). Operations
such as lubricating, draining sumps, servicing of
filters, and inspection for leaks and/or mechanical
malfunction are examples of routine
C-1
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
operations which can be accomplished with effective
production-mode safeguards. However, the replacement of
machine or process equipment components such as valves,
gauges, linkages, support structure, etc. , is not
considered to be normal routine maintenance function
which can safely be accomplished during machine or
process equipment operation. Such maintenance requires
energy isolation and should be evaluated by OSHA field
staff. They also may be an appropriate subject of a
variance request.
4. Several alternative means of safeguarding the hazardous
portions of machines and equipment are presented by the
national consensus standard, ANSI B11.19-1990.
Although that standard is not all inclusive, it
describes effective safeguarding alternatives for the
protection of employees. The safeguards describe
include: interlocked barrier guards, presence sensing
devices and various devices under the exclusive control
of the employee. Such devices or guards, properly
applied, may be used in clearing minor jams and
performing other minor servicing functions which occur
during normal production operations and which meet the
criteria described in paragraph A.2. of this appendix.
B. Group Lockout/Tagout. The group lockout/tagout procedures
described in this instruction at paragraph I.8. require each
authorized employee to be in control of potentially
hazardous energy release during their servicing/maintenance
work assignments. Under most circumstances, where
servicing/maintenance is to be conducted during only one
shift by an individual or a small number of persons working
together, the installation of each individual's
lockout/tagout device upon each energy isolating device
would not be a burdensome procedure. However, when many
energy sources or many persons are involved, and/or the
procedure is to extend over more than one shift, (possibly
several days, or weeks) consideration must be given to the
implementation of a lockout/tagout procedure that will
ensure the safety of the employees involved and will provide
for each individual's control of the energy hazards. The
following procedures are presented as examples to illustrate
the implementation of a group lockout/tagout procedure
involving many energy isolating devices and/or many
servicing/maintenance personnel. They illustrate several
alternatives for having authorized employees affix personal
lockout/
C-2
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
tagout devices in a group lockout/tagout setting. These
examples are not intended to represent the only acceptable
procedures for conducting group operations.
1. Definitions. Various terms used in the examples are
defined below.
a. PRIMARY AUTHORIZED EMPLOYEE is the authorized
employee who exercises overall responsibility for
adherence to the company lockout/tagout procedure.
(See 29 CFR 1910.147(f)(3)(ii)(A).)
b. PRINCIPAL AUTHORIZED EMPLOYEE is an authorized
employee who oversees or leads a group of
servicing/maintenance workers (e.g. , plumbers,
carpenters, electricians, metal workers,
mechanics).
c. JOB-LOCK is a device used to ensure the continuity
of energy isolation during a multi-shift
operation. It is placed upon a lock-box. A key
to the job-lock is controlled by each assigned
primary authorized employee from each shift.
d. JOB-TAG with TAB is a special tag for tagout of
energy isolating devices during group
lockout/tagout procedures. The tab of the tag is
removed for insertion into the lock-box. The
company procedure would require that the tagout
job-tag cannot be removed until the tab is
rejoined to it.
e. MASTER LOCKBOX is the lockbox into which all keys
and tabs from the lockout or tagout devices
securing the machine or equipment are inserted and
which would be secured by a "job-lock" during
multi-shift operations.
f. SATELLITE LOCKBOX is a secondary lockbox or
lock-boxes to which each authorized employee
affixes his/her personal lock or tag.
g. MASTER TAG is a document used as an administrative
control and accountability device. This device is
normally controlled by the operations department
personnel and is a personal tagout device if each
employee personally signs on and signs off on it
and if the tag clearly identifies each authorized
employee who is being protected by it.
C-3
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
h. WORK PERMIT is a control document which authorizes
specific tasks and procedures to be accomplished.
2. Organization. A group lockout/tagout procedure might
provide the following basic organizational structure:
a. A primary authorized employee would be designated.
This employee would exercise primary
responsibility for implementation and coordination
of the lockout/tagout of hazardous energy sources,
for the equipment to be serviced.
b. The primary authorized employee would coordinate
with equipment operators before and after
completion of servicing and maintenance operations
which require lockout/tagout.
c. A verification system would be implemented to
ensure the continued isolation and deenergization
of hazardous energy sources during maintenance and
servicing operations.
d. Each authorized employee would be assured of
his/her right to verify individually that the
hazardous energy has been isolated and/or
deenergized.
e. When more than one crew, craft, department, etc.,
is involved, each separate group of servicing/
maintenance personnel would be accounted for by a
principal authorized employee from each group.
Each principal employee is responsible to the
primary authorized employee for maintaining
accountability of each worker in that specific
group in conformance with the company procedure.
No person may sign on or sign off for another
person, or attach or remove another person's
lockout/tagout device, unless the provisions of
the exception to 29 CFR 1910.147(e)(3) are met.
3. Examples of Procedures for Group Lockout/Tagout.
Examples are presented for the various methods of
lockout/tagout using lockbox procedures. An example of
an applicable method for complex process equipment is
also presented.
a. The following procedures address circumstances
ranging from a small group of servicing/
C-4
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
maintenance employees during a one-shift operation
to a comprehensive operation involving many over a
longer period.
(1) Type A. Each authorized employee places
his/her personal lock or tag upon each energy
isolating device and removes it upon
departure from that assignment. Each
authorized employee verifies or observes the
deenergization of the equipment.
(2) Type B. Under a lockbox procedure, a lock or
job-tag with tab is placed upon each energy
isolation device after deenergization. The
key(s) and removed tab(s) are then placed
into a lockbox. Each authorized employee
assigned to the job then affixes his/her
personal lock or tag to the lockbox. As a
member of a group, each assigned authorized
employee verifies that all hazardous energy
has been rendered safe. The lockout/tagout
devices cannot be removed or the energy
isolating device turned on until the
appropriate key or tab is matched to its lock
or tag.
(3) Type C. After each energy isolating device
is locked/tagged out and the keys/tabs placed
into a master lockbox, each
servicing/maintenance group "principal"
authorized employee places his/her personal
lock or tag upon the master lockbox. Then
each principal authorized employee inserts
his/her key into a satellite lockbox to which
each authorized employee in that specific
group affixes his/her personal lock or tag.
As a member of a group, each assigned
authorized employee verifies that all
hazardous energy has been rendered safe.
Only after the servicing/maintenance
functions of the specific subgroup have been
concluded and the personal locks or tags of
the respective employees have been removed
from the satellite lockbox can the principal
authorized employee remove his/her lock from
the master lockbox.
C-5
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
(4) Type D. During operations to be conducted
over more than one shift (or even many days
or weeks) a system such as described here
might be used. Single locks/tags are affixed
upon a lockbox by each authorized employee as
described at Type B or Type C above. The
master lockbox is first secured with a
job-lock before subsequent locks by the
principal authorized employees are put in
place on the master lockbox. The job-lock
may have multiple keys if they are in the
sole possession of the various primary
authorized employees (one on each shift).
As a member of a group, each assigned
authorized employee verifies that all
hazardous energy has been rendered safe.
In this manner, the security provisions
of the energy control system are
maintained across shift changes while
permitting reenergization of the equipment at
any appropriate time or shift.
b. Normal group lockout/tagout procedures require the
affixing of individual lockout/tagout devices by
each authorized employee to a group lockout
device, as discussed in paragraph B.3.a. of this
appendix. However, in the servicing and
maintenance of sophisticated and complex
equipment, such as process equipment in petroleum
refining, petroleum production, and chemical
production, there may be a need for adaptation and
modification of normal group lockout/tagout
procedures in order to ensure the safety of the
employees performing the servicing and
maintenance. To provide greater worker safety
through implementation of a more feasible system,
and to accommodate the special constraints of the
standard's requirement for ensuring employees a
level of protection equivalent to that provided by
the use of a personal lockout or tagout device, an
alternative procedure may be implemented if the
company documentation justifies it. Lockout/
tagout, blanking, blocking, etc., is often
supplemented in these situations by the use of
work permits and a system of continuous worker
accountability. In evaluating whether the
equipment being serviced or maintained is so
complex as to necessitate a departure from the
normal group lockout/tagout procedures (discussed
C-6
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
in paragraph B.3.a.), to the use of an alternative
procedure as set forth below, the following (often
occurring simultaneously) are some of those which
must be evaluated: physical size and extent of the
equipment being serviced/maintained; the relative
inaccessibility of the energy isolating devices;
the number of employees performing the
servicing/maintenance; the number of energy
isolating devices to be locked/tagged out; and the
interdependence and interrelationship of the
components in the system or between different
systems.
(1) Once the equipment is shut down and the
hazardous energy has been controlled,
maintenance/servicing personnel, together
with operations personnel, must verify that
the isolation of the equipment is effective.
The workers may walk through the affected
work area to verify isolation. If there is a
potential for the release or reaccumulation
of hazardous energy, verification ofisolation
must be continued. The servicing/maintenance
workers may further verify the effectiveness
of the isolation by the procedures that are
used in doing the work (e.g., using a bleeder
valve to verify depressurization,
flange-breaking techniques, etc.). Throughout
the maintenance and/or servicing activity,
operations personnel normally maintain
control of the equipment. The use of the work
permit or "master tag" system (with each
employee personally signing on and signing
off the job to ensure continual employee
accountability and control), combined with
verification of hazardous energy control,
work procedures, and walk-through, is an
acceptable approach to compliance with the
group lockout/tagout and shift transfer
provisions of the standard. (Note, B.1.g. of
this appendix.)
(2) Specific issues related to the control of
hazardous energy in complex process equipment
are described below in a typical situation
which could be found at any facility. This
C-7
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
discussion is intended only as an example and
is not anticipated to reflect operations at
any specific facility.
(a) Complex process equipment which is
scheduled for servicing/maintenance
operations is generally identified by
plant supervision. Plant supervision
would issue specific work orders
regarding the operations to be
performed.
(b) In most instances where complex process
equipment is to be serviced or
maintained, the process equipment
operators can be expected to conduct the
shutdown procedure. This is generally
due to their in-depth knowledge of the
equipment and the need to conduct the
shut-down procedure in a safe, economic
and specific sequence.
(c) The operations personnel will normally
prepare the equipment for lockout/tagout
as they proceed and will identify the
locations for blanks, blocks, etc., by
placing "operations locks and/or tags"
on the equipment. The operations
personnel can be expected to isolate the
hazardous energy, and drain and flush
fluids from the process equipment
following a standard procedure or a
specific work permit procedure.
(d) Upon completion of shutdown, the
operations personnel would review the
intended job with the servicing and
maintenance crew(s) and would ensure
their full comprehension of the energy
controls necessary to conduct the
servicing or maintenance safely. During
or immediately after the review of the
job, the servicing and maintenance crews
would install locks, tags and/or special
isolating devices at previously
identified equipment locations following
the specified work permit procedure.
C-8
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
(e) Line openings necessary for the
isolation of the equipment would
normally be permitted only by special
work permits issued by operations
personnel. (Such line openings should
be monitored by operations personnel as
an added safety measure.)
(f) All of the previous steps should have
been documented by a master system of
accountability and retained at the
primary equipment control station for
the duration of the job. The master
system of accountability may manifest
itself as a Master Tag which is
subsequently signed by all of the
maintenance/servicing workers if they
fully comprehend the details of the job
and the energy isolation devices
actuated or put in place. This signing
by the respective workers further
verifies that energy isolation training
relative to this operation has been
conducted.
(g) After the system has been rendered safe,
the authorized employees verify energy
controls as described in B.3.b.(1) of
this appendix.
(h) Specific work functions are controlled
by work permits which are issued for
each shift. Each day each authorized
employee assigned must sign in on the
work permit at the time of arrival to
the job and sign out at departure.
Signature, date, and time for sign-in
and sign-out would be recorded and
retained by the applicable crew
supervisor who upon completion of the
permit requirements would return the
permit to the operations supervisor.
Work permits could extend beyond a
single shift and may subsequently be the
responsibility of several supervisors.
C-9
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
(i) Upon completion of the tasks required by
the work permit, the authorized
employees' names can be signed off the
Master Tag by their supervisor once all
employees have signed off the work
permit. The work permit is then attached
to the Master Tag. (Accountability of
exposed workers is maintained.)
(j) As the work is completed by the various
crews, the work permits and the
accountability of personnel are
reconciled jointly by the primary
authorized employee and the operations
supervisor.
(k) During the progress of the work,
inspection audits are conducted.
(l) Upon completion of all work, the
equipment is returned to the operations
personnel after the maintenance and
servicing crews have removed their
locks, tags, and/or special isolating
devices following the company procedure.
(m) At this time all authorized employees
who were assigned to the tasks are again
accounted for and verified to be clear
from the equipment area.
(n) After the completion of the servicing/
maintenance work, operations personnel
remove the tags originally placed to
identify energy isolation.
(o) Operations personnel then begin
check-out, verification and testing of
the equipment prior to being returned to
production service.
C. It should be noted that the purpose of the lockout/tagout
standard is to reduce the likelihood of worker injuries and
fatalities during servicing/maintenance operations.
Therefore, when compliance officers inspect workplaces, they
should evaluate the potential for employee exposure to the
C-10
OSHA Instruction STD 1-7.3
SEP 11, 1990
Directorate of Compliance Programs
unexpected release of hazardous energy during
servicing/maintenance operations. When a hazard is noted,
the various requirements of the standard should be applied
in a manner which will result in abatement of the hazardous
circumstance.
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OSHA Directives - Table of Contents
