The document outlines the minor servicing exception to the lockout/tagout (LOTO) standard, which permits certain minor servicing activities during normal production operations without de-energizing machines, provided three specific criteria are met. These criteria include conducting the activity during regular operations, ensuring the activity is routine and integral, and implementing effective alternative protective measures against hazardous energy. Examples, such as milling and blow mold machines, illustrate how operators can safely perform minor tasks while maintaining control over safety measures.

1. Lockout/Tagout:
Minor Servicing Exception

2. Minor Servicing Exception
• Minor tool changes and adjustments, and
other minor servicing activities that take place
during normal production operations, are not
covered by the Lockout/Tagout standard.
• Three specific criteria can be used to
determine if the minor servicing exception
would apply to a particular activity.
• ALL THREE criteria must be met; otherwise
the Lockout/Tagout standard is applicable and
the machine or equipment must be
deenergized and all potentially hazardous
energy rendered safe.

3. Criteria #1
The activity must be conducted
during normal production
operations, i.e., while the machine
or equipment is actually performing
its intended production function.

4. Criteria #2
The activity must be:
• Routine: The activity must be a
regular course of procedure and be
in accordance with established
practices.
• Repetitive: The activity must be
regularly repeated as part of the
production process.
• Integral: The activity must be
essential to the production process.

5. Criteria #3
Employer must use alternative measures
to provide effective protection from the
hazardous energy, such as:
• specially designed tools,
• remote devices,
• interlocked barrier guards,
• local disconnects,
• or control switches which are under
the exclusive control of the employee
performing the minor servicing.
Using an extension tool to
prevent employee injury.

7. Effectiveness of Alternative Measures
• Alternative measures must be evaluated
to ensure they provide effective
protection from hazardous energy.
• EXAMPLE: In order for the clearing of a
conveyor package jam to meet the
criteria for the “minor servicing”
exception, an employer must adopt
alternative measures that provide
effective protection in order to avoid
the LOTO requirements for machine
maintenance.

8. Effectiveness of Alternative Measures
• A CSHO should consider all of the steps taken
by an employer to provide alternative,
effective protection (e.g., training,
disciplinary provisions, engineering controls,
start-up alarms/delays, administrative
provisions, near miss and related-injury data,
etc.) in order to ascertain whether the
alternative, including all of its steps, reliably
prevents an employee from being injured by
hazardous energy when performing servicing
and maintenance activities under the “minor
servicing” exception.

9. Example: Milling Machine
• Vertical and horizontal milling machine operators
perform minor tool changes and minor adjustments
(e.g., minor belt drive adjustments; moving the coolant
hose assembly close to the point of operation) that are
integral to the production process by pushing the
machine's stop button (without disconnecting the power
supply to the machine) and perform the task in the close
proximity of the start button.
• All that is required to restart the machine is to push a
guarded start button; however, an operator has
exclusive control of this shutoff control circuit because
he could easily see another person approaching the
control panel and prevent her from operating the
control.

10. Example: Milling Machine
• In this scenario, milling machine
operators who shut off the machine and
exercise exclusive control over this
control circuit would NOT need to
implement LOTO.
• However, the minor servicing would be
covered by the LOTO standard if the
alternative work method becomes
ineffective (i.e., there is no alternative
employee protection) and exposes
employees to machine hazards.

11. Example: Blow Mold Machine
• Blow mold machine operators perform
minor un-jamming tasks, during normal
production operations, at the machine’s
trimmer unit on a routine and repetitive
basis to remove stuck plastic containers.
• This operator shuts the machines off
with the control circuit switch (stop
button) and she opens an interlocked
plexiglass barrier guard to gain access to
the trimmer’s point-of-operation area.

12. Example: Blow Mold Machine
• The employer utilizes a guard system, designed
by the manufacturer in accordance with
recognized and generally accepted good
engineering practices, that causes the
mechanical interlock switch to break the electric
circuit when the guard is moved for employee
access purposes and shuts down the machine.
• Within the context of the minor servicing
exception, the described and properly applied
interlocked plexiglass guard system, together
with the operator’s exclusive control of the
control circuit devices, constitute alternative
measures which constitute effective protection.

13. Example: Monitored Power System
• The automotive industry designs some processes
with Monitored Power System (MPS) control
systems meeting the control reliability and
control component failure protection
requirements of the American National Standards
for machine tools (ANSI B11.19-1990) and
manufacturing systems/cells (ANSI B11.20-1991).
• Although control circuits are not energy-isolating
devices, as defined by the standard, the use of
MPS which meet the above referenced ANSI
standards would provide effective safeguarding
alternative methods, which constitute effective
alternative protection.

14. Example: Monitored Power System
• Thus, such an MPS may be used to
protect employees who are
performing minor tool changes and
adjustments, and other minor
servicing activities, which take place
during normal production
operations, provided that other
remaining elements of
§1910.147(a)(2)(ii) exception are
met.