Lockout/Tagout Procedures 141

"Lockout/Tagout Procedures" details the OSHA requirements and best practices for preventing accidental startup during maintenance and repair. It addresses electrical power and the many other forms of energy that a machine or device may use. All forms of energy must be successfully restrained or dissipated in order for safe maintenance. "Lockout/Tagout Procedures" describes using a lockout device that prevents unauthorized access of the energy-isolating mechanism. OSHA has strict requirements for lockout and tagout devices, which must be standardized, easily recognized warning signs. Users will learn OSHA's specific steps for all parts of the control of hazardous energy, from shutdown to startup, including defining authorized vs. affected employees.

Following proper lockout/tagout procedures is essential to preventing employee injuries and fatalities. All employees must be familiar with lockout/tagout in order to prevent the dangers of accidental machine startup.

Class Details

Class Name:
Lockout/Tagout Procedures 141
Number of Lessons:

Class Outline

  • What Is Lockout/Tagout?
  • Forms of Energy
  • Lockout Devices
  • Energy Review
  • Tagout Devices
  • Requirements for Lockout/Tagout Devices
  • Determining Devices for Lockout
  • Knowing When the Standard Applies
  • Blocking Devices and Methods
  • Lockout/Tagout Standards Review
  • Energy Control Program
  • Affected and Authorized Employees
  • Typical Minimal Lockout Procedure
  • Steps in the Typical Minimal Lockout Procedure
  • Typical Minimal Lockout Procedure: Restoring Power
  • Reviewing Lockout/Tagout Procedures
  • Training
  • Preventing Accidents
  • Final Review


  • Define lockout/tagout.
  • Describe the forms of energy that may be found in a manufacturing environment.
  • Define lockout device.
  • Describe tagout devices.
  • List OSHA requirements for lockout/tagout devices.
  • Describe lockout capability requirements for machinery.
  • Describe when the lockout/tagout standard applies.
  • Identify methods of blocking.
  • Describe the basic requirements of an energy control program.
  • Distinguish between affected and authorized employees.
  • Describe OSHA's typical minimal lockout procedure.
  • List the steps in the lockout sequence for a typical minimal lockout procedure.
  • List the sequence of steps for restoring equipment to service after lockout.
  • Describe lockout/tagout training requirements for different types of employees.
  • Explain the importance of continuity during the lockout/tagout procedure.

Job Roles


  • CMfgA
  • CNC Lathe Operations
  • CNC Milling Operations
  • CNC Milling Programming, Setup, & Operation
  • CNC Milling: Operations-FastTrack
  • CNC Milling: Programming, Setup, and Operations-FastTrack
  • CNC Turning Programming, Setup, & Operation
  • CNC Turning: Operations-FastTrack
  • CNC Turning: Programming, Setup, and Operations-FastTrack
  • Drill Press I
  • Drill Press Skills-FastTrack
  • Grinding I
  • Grinding Skills-FastTrack
  • Job Planning, Benchwork, & Layout I
  • Job Planning, Benchwork, and Layout-FastTrack
  • Manual Milling Skills-FastTrack
  • Measurement, Materials, & Safety I
  • Measurement, Materials, and Safety-FastTrack
  • Milling I
  • Turning Operations: Turning Between Centers-FastTrack
  • Turning Operations: Turning Chucking Skills
  • Turning Operations: Turning Chucking Skills-FastTrack
  • MSSC Fast Track Safety


Vocabulary Term Definition
affected employee An employee who normally works on or near a machine that must be locked out for maintenance. Affected employees include any employee in a manufacturing environment.
assembly The process by which multiple objects are joined together. Assembly includes using fasteners or adhesives to attach parts to one another.
authorized employees An employee who is qualified to lock out machinery and perform maintenance. All maintenance or service personnel are considered authorized employees.
bleeding The process of safely removing liquid or gas from a closed system. Bleeding can remove potential energy and prevent accidental machine movements.
blocking The use of physical or mechanical barriers or restraints to prevent accidental machine startup or release of energy. Blocking is a safety measure used along with lockout/tagout during machine maintenance.
cable tie A long, thin plastic or nylon fastening device that locks when the point on one end is threaded through the loop on the other. Cable ties are also be known as zip ties.
caustic Capable of burning or destroying living tissue through chemical processes. Many common workplace chemicals are caustic.
chemical energy Power created by the reaction between two or more substances. Chemical energy is used to power batteries.
circuit breaker locks A device that can be locked in place over a specific circuit breaker within a breaker box. Circuit breaker locks prevent electricity from accidentally being supplied to a specific area, machine, or device.
Control of Hazardous Energy The official title of the OSHA lockout/tagout safety standard. The standard protects employees by requiring preventive steps against accidental machine startup during maintenance.
electrical energy Power created by the movement of electrons. Electrical energy, or electricity, can cause injury through electric shock.
energy control program A written procedure that explains how to control hazardous energy in a specific workplace. Energy control programs are required by OSHA and developed by individual employers to cover their workplaces.
energy isolating mechanism A mechanical device that physically controls the transmission or release of energy. Energy isolating mechanisms include on/off switches, circuit breakers, and valves.
energy isolation mechanisms A mechanical device that physically controls the transmission or release of energy. Energy isolation mechanisms include on/off switches, circuit breakers, and valves.
fastener A device that holds objects together or locates them in relation to one another. Common fasteners include bolts, screws, pins, and rivets.
gravity The force which draws and holds things to the surface of the earth. Gravity can pull machine components downward even when the machine is shut off.
grounding Directing stray electrical current to a safe, neutral source. Grounding generally uses a wire to connect a conductive object to a rod driven into the ground.
hasp A locking mechanism consisting of a hinged closure with a slot that closes over a loop, which is then secured with a lock. Hasps support padlocks, combination locks, and other locking devices.
hydraulic energy Power created by the compressive force or movement of a liquid in a confined area. Machines that lift objects often use hydraulic energy.
kinetic energy Power caused by movement. Kinetic energy is produced by moving components such as gears and springs.
levers A bar or linear device that pivots on a fixed point to transfer force and motion. Levers use kinetic energy.
lockable electric disconnect switch A power switch that can be shut off and then locked in the off position. Lockable electric disconnect switches often control the entire power supply for a room or device.
lockable valve covers A device that closes over a valve and can be locked shut. Lockable valve covers prevent valves from being accidentally opened or turned to the on position.
lockout device A device that holds an energy-isolating mechanism in a safe position using a lock or other locking object. Lockout devices prevent equipment or machinery from being energized.
lockout/tagout A method of protecting employees by preventing accidental machine startup through proper locking and labeling of machines during maintenance. Lockout/tagout is the common term for OSHA's Control of Hazardous Energy Standard.
machine guards A shield or cover over hazardous areas on a machine. Machine guards prevent accidental contact with body parts or prevent debris, such as chips, from exiting the machine.
maintenance The necessary and basic support and repair of machines. Maintenance includes tasks such as lubricating, adjusting, and replacing parts.
mechanical energy A combination of kinetic and potential energy. Mechanical energy results from the force of gravity or the movement or release of a machine component, such as a spring, clamp, or wheel.
Occupational Safety and Health Administration OSHA. A government agency under the U.S. Dept. of Labor that sets the standards for working conditions in the United States. OSHA ensures that employees work in safe and healthy environments.
pneumatic energy Power created by the compressive force or movement of air or gas in a confined area. Assembly tools often use pneumatic energy.
potential energy Stored energy resulting from an object's position or internal pressure. Potential energy often exists in machines that have been turned off.
print format The appearance of letters on an object or device, including style, color, and size. Tagout devices have a standardized print format.
springs A flexible device used to apply force, control motion, and store energy. Springs are generally composed of coiled metal wire.
tagout devices A prominent visual warning device that can be securely attached to an energy-isolating mechanism during machine repair or maintenance. Tagout devices alert employees that equipment must not be operated until the tag is removed.
tension A force that attempts to pull, stretch, or elongate an object. Belt drives and springs use tension.
thermal energy Power created by or in the form of heat. Thermal energy can be retained in machine parts and cause burns.
typical minimal lockout procedure The essential steps required to lock out a specific machine. Typical minimal lockout procedures are required by OSHA as part of an energy control program.
welding A joining process that uses heat, pressure, or chemicals to permanently fuse materials together. Welding generally involves high heat and sparks.
zip tie A long, thin plastic or nylon fastening device that locks when the point on one end is threaded through the loop on the other. Zip ties are also known as cable ties.