Key Terms

The following definitions apply to this course.

Affected employee: An employee whose job includes operating or using a machine on which maintenance is being performed under lockout or tagout, or whose job requires working in an area where such maintenance is being performed.

Authorized employee: A person who locks out or tags out a machine in order to service or maintain that machine. An affected employee becomes an authorized employee when that employee's duties include relevant service or maintenance.

Capable of being locked out: An energy-isolating device is capable of being locked out if it has a hasp or other means of attachment to which, or through which, a lock can be affixed, or it has a locking mechanism built into it. Other energy-isolating devices are capable of being locked out, if lockout can be achieved without the need to dismantle, rebuild, or replace the energy-isolating device or permanently alter its energy control capability.

Energized: Connected to an energy source, or containing residual or stored energy.

Energy-isolating device: A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following:

• A manually operated electrical circuit breaker
• A disconnect switch
• A manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently
• A line valve
• A block
• Any similar device used to block or isolate energy

Please note that push buttons, selector switches, and other control circuit type devices are not energy-isolating devices.

Energy source: Any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other energy.

Hot tap: A procedure that involves welding on a piece of equipment (pipelines, vessels, or tanks) under pressure in order to install connections or appurtenances. A hot tap is commonly used to replace or add sections of pipeline without the interruption of service for air, gas, water, steam, and petrochemical distribution systems.

Lockout: The placement of a lockout device on an energy-isolating device, in accordance with an established procedure, ensuring that the energy-isolating device and the equipment being controlled cannot be operated until the lockout device is removed. When used as a verb, it is two words: We must lock out the machine. When used as a noun, it is one word: The lockout may seem inconvenient, but it is for your safety.

Lockout device: A device that uses a positive means such as a lock (either key or combination type) to hold an energy-isolating device in the safe position and prevent the energizing of a machine. Lockout devices include blank flanges and bolted slip blinds.

Lockout/tagout (LOTO): A safety procedure used to ensure that dangerous machines are properly de-energized (shut off) and not able to be started up again until after the completion of maintenance or repair work.

Normal production operations: Machines functioning as intended.

Servicing or maintenance: Workplace activities such as constructing, installing, setting up, adjusting, inspecting, modifying, maintaining, and servicing machines. These activities include lubrication, cleaning, unjamming, adjusting, or tool changing, where the employee may be exposed to the unexpected energization or startup of the equipment or a release of hazardous energy.

Setting up: Work performed to prepare a machine to perform its normal production operation.

Tagout: The placement of a tagout device on an energy-isolating device, in accordance with an established procedure, to indicate that the energy-isolating device and the equipment being controlled may not be operated until the tagout device is removed. This term is one word when used as a noun; two words when used as a verb.

Tagout device: A prominent warning device, such as a tag and a means of attachment, which can be securely fastened to an energy-isolating device in accordance with an established procedure to indicate that the energy-isolating device and the equipment being controlled may not be operated until the tagout device is removed.

To learn more about Lockout/Tagout visit our Lockout/Tagout Online Training web page.