OSHA Lockout / Tagout (LOTO) Exam Prep – Real Practice Questions,
Answers & Detailed Rationales (Updated 2026) | Hazardous Energy
Control Procedures, OSHA Lockout / Tagout Standards, Electrical &
Mechanical Equipment Safety, Machine Shutdown & Isolation Techniques,
Authorized vs Affected Employees, Energy Source Identification,
Workplace Injury Prevention & Occupational Safety Compliance Review
Question 1: According to OSHA 29 CFR 1910.147, what is the primary purpose of the
Lockout/Tagout standard?
A. To reduce equipment maintenance costs
B. To prevent unexpected energization, startup, or release of stored energy during
servicing and maintenance
C. To standardize electrical wiring practices across industries
D. To require all equipment to have automatic shutoff features
CORRECT ANSWER: B. To prevent unexpected energization, startup, or release of
stored energy during servicing and maintenance
Rationale:The fundamental purpose of 29 CFR 1910.147 is to protect employees from
hazardous energy by requiring procedures that isolate energy sources and prevent
unexpected energization, startup, or release of stored energy during servicing and
maintenance activities.
Question 2: Which of the following best defines an "authorized employee" under
OSHA's Lockout/Tagout standard?
A. Any employee who works near equipment undergoing maintenance
B. An employee who operates equipment during normal production
C. A person who locks out or tags out machines or equipment to perform servicing or
maintenance
D. A supervisor who approves maintenance work orders
CORRECT ANSWER: C. A person who locks out or tags out machines or equipment
to perform servicing or maintenance
Rationale:OSHA defines an authorized employee as a person who locks out or tags out
machines or equipment in order to perform servicing or maintenance on that machine
or equipment. This employee has received specific training on energy control
procedures.
Question 3: What distinguishes a "lockout device" from other safety equipment
under 29 CFR 1910.147?
A. It is always red in color
B. It uses a positive means such as a lock to hold an energy isolating device in a safe
position
C. It can be removed by any supervisor
D. It is only used for electrical energy sources
,CORRECT ANSWER: B. It uses a positive means such as a lock to hold an energy
isolating device in a safe position
Rationale:A lockout device is defined as a device that uses a positive means, such as a
lock (key or combination type), to hold an energy isolating device in a safe position and
prevent the energizing of a machine or equipment.
Question 4: Which of the following is NOT considered an "energy isolating device"
under OSHA standards?
A. A manually operated electrical circuit breaker
B. A disconnect switch
C. A push button control switch
D. A line valve
CORRECT ANSWER: C. A push button control switch
Rationale:OSHA explicitly states that push buttons, selector switches, and other
control circuit type devices are NOT energy isolating devices because they do not
physically prevent the transmission or release of energy.
Question 5: What is the definition of "tagout" according to 29 CFR 1910.147?
A. The physical removal of an energy source from equipment
B. The placement of a tagout device on an energy isolating device to indicate that
operation is prohibited until removal
C. The use of warning signs posted near equipment
D. The electronic monitoring of equipment status
CORRECT ANSWER: B. The placement of a tagout device on an energy isolating
device to indicate that operation is prohibited until removal
Rationale:Tagout is defined as 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.
Question 6: An "affected employee" under the Lockout/Tagout standard is best
described as:
A. An employee who has been injured during a lockout procedure
B. An employee whose job requires operating equipment on which servicing is being
performed under lockout/tagout
C. An employee who writes lockout procedures
D. An employee who audits lockout compliance
CORRECT ANSWER: B. An employee whose job requires operating equipment on
which servicing is being performed under lockout/tagout
,Rationale:An affected employee is defined as a person whose job requires them to
operate or use a machine or equipment on which servicing or maintenance is being
performed under lockout or tagout, or whose job requires them to work in an area where
such servicing is being performed.
Question 7: What does "capable of being locked out" mean regarding an energy
isolating device?
A. The device can be locked without dismantling, rebuilding, or permanently altering it
B. The device has a built-in electronic lock
C. The device can only be locked by the equipment manufacturer
D. The device requires special tools to operate
CORRECT ANSWER: A. The device can be locked without dismantling, rebuilding, or
permanently altering it
Rationale:An energy isolating device is considered capable of being locked out if it is
designed with a hasp or attachment point for a lock, has a built-in locking mechanism,
or can be locked without dismantling, rebuilding, replacing, or permanently altering the
device.
Question 8: Which energy source is NOT explicitly covered under the scope of 29
CFR 1910.147?
A. Electrical energy
B. Hydraulic energy
C. Gravitational potential energy
D. Nuclear energy
CORRECT ANSWER: D. Nuclear energy
Rationale:OSHA 1910.147 covers mechanical, hydraulic, pneumatic, chemical,
thermal, electrical, and other energy sources. Nuclear energy is regulated under
separate federal regulations (e.g., NRC) and is not within the scope of this general
industry standard.
Question 9: What is a "hot tap" operation as referenced in the Lockout/Tagout
standard?
A. A procedure for testing lockout devices under high temperature
B. Welding on pressurized equipment to install connections without interrupting service
C. A method for rapidly applying tagout devices
D. A technique for removing stored thermal energy
CORRECT ANSWER: B. Welding on pressurized equipment to install connections
without interrupting service
Rationale:A hot tap is a procedure used in repair and maintenance that involves welding
on equipment under pressure to install connections, commonly used for pipelines
carrying gas, water, steam, or petroleum without interrupting service.
, Question 10: When does an affected employee become an authorized employee
under OSHA standards?
A. When they complete a general safety orientation
B. When their duties include performing servicing or maintenance covered by the
standard
C. When they witness a lockout procedure
D. When they are promoted to a supervisory role
CORRECT ANSWER: B. When their duties include performing servicing or
maintenance covered by the standard
Rationale:OSHA specifies that an affected employee becomes an authorized employee
when that employee's duties include performing servicing or maintenance covered
under the Lockout/Tagout standard, requiring additional training.
Question 11: Which of the following is a required characteristic of lockout devices
under 29 CFR 1910.147?
A. They must be transparent for visual inspection
B. They must be substantial enough to prevent removal without excessive force
C. They must be disposable after single use
D. They must be electronically monitored
CORRECT ANSWER: B. They must be substantial enough to prevent removal
without excessive force
Rationale:Lockout devices must be substantial enough to prevent removal without the
use of excessive force or unusual techniques such as bolt cutters or other metal cutting
tools, ensuring they cannot be easily bypassed.
Question 12: What is the minimum unlocking strength required for the attachment
means of a tagout device?
A. 25 pounds
B. 35 pounds
C. 50 pounds
D. 75 pounds
CORRECT ANSWER: C. 50 pounds
Rationale:Tagout device attachment means must be non-reusable, attachable by hand,
self-locking, non-releasable, and have a minimum unlocking strength of no less than 50
pounds, equivalent to a one-piece all-environment-tolerant nylon cable tie.
Question 13: Which legend is NOT an acceptable warning on a tagout device per
OSHA requirements?
A. Do Not Start
B. Do Not Operate
Answers & Detailed Rationales (Updated 2026) | Hazardous Energy
Control Procedures, OSHA Lockout / Tagout Standards, Electrical &
Mechanical Equipment Safety, Machine Shutdown & Isolation Techniques,
Authorized vs Affected Employees, Energy Source Identification,
Workplace Injury Prevention & Occupational Safety Compliance Review
Question 1: According to OSHA 29 CFR 1910.147, what is the primary purpose of the
Lockout/Tagout standard?
A. To reduce equipment maintenance costs
B. To prevent unexpected energization, startup, or release of stored energy during
servicing and maintenance
C. To standardize electrical wiring practices across industries
D. To require all equipment to have automatic shutoff features
CORRECT ANSWER: B. To prevent unexpected energization, startup, or release of
stored energy during servicing and maintenance
Rationale:The fundamental purpose of 29 CFR 1910.147 is to protect employees from
hazardous energy by requiring procedures that isolate energy sources and prevent
unexpected energization, startup, or release of stored energy during servicing and
maintenance activities.
Question 2: Which of the following best defines an "authorized employee" under
OSHA's Lockout/Tagout standard?
A. Any employee who works near equipment undergoing maintenance
B. An employee who operates equipment during normal production
C. A person who locks out or tags out machines or equipment to perform servicing or
maintenance
D. A supervisor who approves maintenance work orders
CORRECT ANSWER: C. A person who locks out or tags out machines or equipment
to perform servicing or maintenance
Rationale:OSHA defines an authorized employee as a person who locks out or tags out
machines or equipment in order to perform servicing or maintenance on that machine
or equipment. This employee has received specific training on energy control
procedures.
Question 3: What distinguishes a "lockout device" from other safety equipment
under 29 CFR 1910.147?
A. It is always red in color
B. It uses a positive means such as a lock to hold an energy isolating device in a safe
position
C. It can be removed by any supervisor
D. It is only used for electrical energy sources
,CORRECT ANSWER: B. It uses a positive means such as a lock to hold an energy
isolating device in a safe position
Rationale:A lockout device is defined as a device that uses a positive means, such as a
lock (key or combination type), to hold an energy isolating device in a safe position and
prevent the energizing of a machine or equipment.
Question 4: Which of the following is NOT considered an "energy isolating device"
under OSHA standards?
A. A manually operated electrical circuit breaker
B. A disconnect switch
C. A push button control switch
D. A line valve
CORRECT ANSWER: C. A push button control switch
Rationale:OSHA explicitly states that push buttons, selector switches, and other
control circuit type devices are NOT energy isolating devices because they do not
physically prevent the transmission or release of energy.
Question 5: What is the definition of "tagout" according to 29 CFR 1910.147?
A. The physical removal of an energy source from equipment
B. The placement of a tagout device on an energy isolating device to indicate that
operation is prohibited until removal
C. The use of warning signs posted near equipment
D. The electronic monitoring of equipment status
CORRECT ANSWER: B. The placement of a tagout device on an energy isolating
device to indicate that operation is prohibited until removal
Rationale:Tagout is defined as 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.
Question 6: An "affected employee" under the Lockout/Tagout standard is best
described as:
A. An employee who has been injured during a lockout procedure
B. An employee whose job requires operating equipment on which servicing is being
performed under lockout/tagout
C. An employee who writes lockout procedures
D. An employee who audits lockout compliance
CORRECT ANSWER: B. An employee whose job requires operating equipment on
which servicing is being performed under lockout/tagout
,Rationale:An affected employee is defined as a person whose job requires them to
operate or use a machine or equipment on which servicing or maintenance is being
performed under lockout or tagout, or whose job requires them to work in an area where
such servicing is being performed.
Question 7: What does "capable of being locked out" mean regarding an energy
isolating device?
A. The device can be locked without dismantling, rebuilding, or permanently altering it
B. The device has a built-in electronic lock
C. The device can only be locked by the equipment manufacturer
D. The device requires special tools to operate
CORRECT ANSWER: A. The device can be locked without dismantling, rebuilding, or
permanently altering it
Rationale:An energy isolating device is considered capable of being locked out if it is
designed with a hasp or attachment point for a lock, has a built-in locking mechanism,
or can be locked without dismantling, rebuilding, replacing, or permanently altering the
device.
Question 8: Which energy source is NOT explicitly covered under the scope of 29
CFR 1910.147?
A. Electrical energy
B. Hydraulic energy
C. Gravitational potential energy
D. Nuclear energy
CORRECT ANSWER: D. Nuclear energy
Rationale:OSHA 1910.147 covers mechanical, hydraulic, pneumatic, chemical,
thermal, electrical, and other energy sources. Nuclear energy is regulated under
separate federal regulations (e.g., NRC) and is not within the scope of this general
industry standard.
Question 9: What is a "hot tap" operation as referenced in the Lockout/Tagout
standard?
A. A procedure for testing lockout devices under high temperature
B. Welding on pressurized equipment to install connections without interrupting service
C. A method for rapidly applying tagout devices
D. A technique for removing stored thermal energy
CORRECT ANSWER: B. Welding on pressurized equipment to install connections
without interrupting service
Rationale:A hot tap is a procedure used in repair and maintenance that involves welding
on equipment under pressure to install connections, commonly used for pipelines
carrying gas, water, steam, or petroleum without interrupting service.
, Question 10: When does an affected employee become an authorized employee
under OSHA standards?
A. When they complete a general safety orientation
B. When their duties include performing servicing or maintenance covered by the
standard
C. When they witness a lockout procedure
D. When they are promoted to a supervisory role
CORRECT ANSWER: B. When their duties include performing servicing or
maintenance covered by the standard
Rationale:OSHA specifies that an affected employee becomes an authorized employee
when that employee's duties include performing servicing or maintenance covered
under the Lockout/Tagout standard, requiring additional training.
Question 11: Which of the following is a required characteristic of lockout devices
under 29 CFR 1910.147?
A. They must be transparent for visual inspection
B. They must be substantial enough to prevent removal without excessive force
C. They must be disposable after single use
D. They must be electronically monitored
CORRECT ANSWER: B. They must be substantial enough to prevent removal
without excessive force
Rationale:Lockout devices must be substantial enough to prevent removal without the
use of excessive force or unusual techniques such as bolt cutters or other metal cutting
tools, ensuring they cannot be easily bypassed.
Question 12: What is the minimum unlocking strength required for the attachment
means of a tagout device?
A. 25 pounds
B. 35 pounds
C. 50 pounds
D. 75 pounds
CORRECT ANSWER: C. 50 pounds
Rationale:Tagout device attachment means must be non-reusable, attachable by hand,
self-locking, non-releasable, and have a minimum unlocking strength of no less than 50
pounds, equivalent to a one-piece all-environment-tolerant nylon cable tie.
Question 13: Which legend is NOT an acceptable warning on a tagout device per
OSHA requirements?
A. Do Not Start
B. Do Not Operate
