STD 1-7.3 - 29 CFR 1910.147, the Control of Hazardous
(Lockout/Tagout) - Inspection Procedures and Interpretive Guidance
- 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
||29 CFR 1910.147, the Control of
Hazardous Energy (Lockout/Tagout)--Inspection Procedures and
- Purpose. This instruction establishes
policies and provides clarification to ensure uniform enforcement of the
- Scope. This instruction applies OSHA-wide.
- General Industry Standards, 29 CFR 1910,
Subpart O, Subpart S, and other specific subparts.
- OSHA Instruction CPL 2.45B, June 15, 1989,
the Revised Field Operations Manual (FOM).
- 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.
- 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.
- Federal Program Change. This instruction
describes a Federal program change which affects State programs. Each
Regional Administrator shall:
- Ensure that this change is forwarded to
each State designee.
- Explain the technical content of this
change to the State designee as requested.
- 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
Stat's alternative guidelines which are "at least as effective" as the
- 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.
- 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.
- 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.
- Review policies, instructions and
guidelines issued by the State to determine that this change has been
communicated to State personnel.
- 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.
- 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.
- 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.
- 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.
- Inspection Guidelines. The standard
incorporates performance requirements which allow employers flexibility
in developing lockout/tagout programs suitable for their particular
- 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.
- Evaluations of compliance with 29 CFR
1910.147 shall be conducted during all general industry inspection
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.
- 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:
- 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
- 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.
- 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)).
||Verify that the training of
authorized employees includes:
||Recognition of hazardous energy;
||Type and magnitude of energy
found in the workplace;
||The means and methods of
isolating and/or controlling energy; and
||The means of verification of
effective energy control, and the purpose of the procedures
to be used.
||Verify that affected employees have
been instructed in the purpose and use of the energy control
||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.
||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).
- Evaluate the employer's manner of
enforcing the program (29 CFR 1910.147 (c)(4)(ii)).
- 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:
- Evaluate compliance with the requirements
for periodic inspection of procedures.
- Ensure that the person performing the
periodic inspection is an authorized employee other than the one(s)
utilizing the procedure being inspected.
- Evaluate compliance with retraining
requirements which result from the periodic inspection of procedures
and practices, or from changes in equipment/processes.
- Evaluate the employer's procedures for
assessment, and correction of deviations of inadequacies identified
during periodic inspections of the energy control procedure.
- Identify the procedures for release from
||Replacement of safeguards, machine or
equipment inspection, and removal of non-essential tools and
||Safe positioning of employees;
||Removal of lockout/tagout device(s); and
||Notification of affected employees that
servicing and maintenance is completed.
- 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
- 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.
- 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
- Scope of the Standard.
- The standard as specified in 29 CFR
1910.147(b), applies to any source of mechanical, hydraulic,
pneumatic, chemical, thermal, or other energy.
||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
||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
||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.)
- The standard does not apply to servicing
and maintenance when employees are not exposed to the unexpected
released of hazardous energy.
- Safeguarding workers from the hazards of
contacting electrically live parts (exposure to electric current)
continues to be regulated at Subpart S.
- Servicing and maintenance functions
conducted during normal production operations are not regulated at
29 CFR 1910.147 if the safeguarding 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
- 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
NOTE: Appendix C, section A, provides
further guidance in this area.
- 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.
||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.
||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
- 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.
- 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.
- 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
- Lockout vs. Tagout.
- OSHA has determined that lockout is a
surer means of ensuring deenergization of equipment than tagout, and
that it is the preferred method.
- 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 disconnecting device, or the removal of a valve handle to
reduce the likelihood of inadvertent energization.)
- 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.
- 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.
- 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
- 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
- Employees and Training.
- 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
- 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.)
- 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)).
- The employer must provide:
||Effective initial training;
||Effective retraining as needed; and
||Certification of training. The
certification shall contain each employee's name and dates of
- Retraining of authorized and affected employees is required:
||Whenever there is a change in employee job
||Whenever a new hazard is introduced due to
a change in machines, equipment or process;
||Whenever there is a change in the energy
control procedures; or
||Whenever a periodic inspection by the
employer reveals inadequacies in the company procedures or in
the knowledge of the employees.
- Periodic Inspection by the Employer
- 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 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)).
||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
||When tagout is used, the employer shall
conduct this review with each affected and authorized employee.
||Energy control procedures used less
frequently than once a year need be inspected only when used.
- The periodic inspection must provide for and ensure effective
correction of identified deficiencies (29 CFR 1910.147(c)(6)(i)(B)).
- The employer is required to certify that the prescribed periodic
inspections have been performed (29 CFR 1910.147(c)(6)(ii)).
- 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.
- 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 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.
- 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
- 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.
- Compliance with Group Lockout/Tagout. These operations shall, at a
minimum, provide for the following:
- 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.
- 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)).
- All energy isolating devices needed to isolate the machine or
equipment shall be effectively positioned and/or installed (29 CFR
- 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
||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
||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)).
||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
- 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
||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)).
||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
- 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.
- Release from lockout/tagout shall be accomplished in compliance
with the requirements at 29 CFR 1910.147(e).
||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)).
||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)).
||In all instances, the company procedure
must provide a system which identifies each authorized employee
involved in the servicing/maintenance operation.
||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
- 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
- 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.
- 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
- 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
- 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
- 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
- Classification of Violations.
- 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
- The failure to train "authorized", "affected", and "other"
employees as required for their respective classifications should
normally be cited as a serious violation.
- Paperwork deficiencies in lockout/tagout programs where effective
lockout/tagout work procedures are in place shall be cited as
- 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
||National, Regional, and Area Offices
All Compliance Officers
NIOSH Regional Program Directors
7(c)(1) Consultation Project Managers
OSHA Training Institute
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
Overhead and Gantry Cranes
1910.179(g)(5)(i), (ii), (iii)
Mechanical Power Presses
1910.218(f)(1)(i), (ii), (iii)
Welding, Cutting and Brazing
Pulp, Paper and Paperboard Mills
1910.265(c)(12)(v), 1910.265(c)(13), 1910.265(c)(26)(v)