Hazardous Energy Control
/ Lock out Tag out (LOTO)
1
What is Hazardous Energy?
Hazardous energy is defined by the Canadian Standards Association (CSA) as: "any electrical,
mechanical, pneumatic, chemical, nuclear, thermal, gravitational, or other energy that can
harm people" (CSA Z460 "Control of Hazardous Energy - Lockout and Other Methods"). Some
energy sources are obvious, such as electricity, heat in a furnace, or something that
might
fall.
Others
may
be
hidden
hazards
such as
air
pressure
in
a system or
a tightly
wound
spring.
2
What are Types of Hazardous Energy?
Electrical energy is the most common form of energy used in workplaces. It can be available live
through power lines or it can also be stored, for example, in batteries or capacitors. Electricity can
harm people in one of three ways:
1.By
2.By
3.By
electrical shock.
secondary injury.
exposure to an electrical arc.
Hydraulic potential energy is the energy stored within a pressurized liquid. When under pressure,
the fluid can be used to move heavy objects, machinery, or equipment. Examples include: automotive car lifts, injection molding machines, power presses, and the braking system in cars. When hydraulic energy is released in an uncontrolled manner, individuals may be crushed or struck by moving machinery, equipment or other items
Pneumatic potential energy is the energy stored within pressurized air. Like hydraulic energy, when under pressure, air can be used to move heavy objects and power equipment. Examples include
spraying
devices,
power
washers, or machinery.
When
pneumatic
energy
is
released
in
an
uncontrolled manner, individuals may be crushed or struck by moving machinery, equipment or other
items.
3
What are Types of Hazardous Energy?
Chemical energy is the energy released when a substance undergoes a chemical reaction. The
energy is normally released as heat, but could be released in other forms, such as pressure. A
common result of a hazardous chemical reaction is fire or explosion.
Radiation energy is energy from electromagnetic sources. This energy covers all radiation from visible light, lasers, microwave, infra red, ultraviolet, and X-rays. Radiation energy can cause health effects ranging from skin and eye damage (lasers and UV light) to cancer (X-rays).
Gravitational potential energy is the energy related to the mass of an object and its distance from the earth (or ground). The heavier an object is, and the further it is from the ground, the greater its gravitational potential energy. For example, a 1 kilogram (kg) weight held 2 meters above the ground will have greater gravitational potential energy then a 1 kg held 1 meter above the ground.
Mechanical energy is the energy contained in an item under tension. For instance, a spring that is compressed or coiled will have stored energy which will be released in the form of movement when the spring expands. The release of mechanical energy may result in an individual being crushed or struck by the object.
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Example
It is important to understand that all of these energy types can be considered as either the primary
energy source, or as residual or stored energy (energy that can reside or remain in the system)
Primary energy source is the supply of power that is used to perform work.
Residual or stored energy is energy within the system that is not being used, but when released it can cause work to be done.
For example: when you close a valve on a pneumatic (air) or hydraulic (liquid) powered system, you have isolated the system from its primary energy source. However, there is still residual energy stored in any air or liquid that remains in the system. In this example, removing the residual energy would
include bleeding out the liquid, or venting out the air. Until this residual energy is removed from
system, work can occur, whether on purpose or inadvertently
Not properly assessing and dissipating stored energy is one of the most common causes workplace incidents that involve hazardous energy. Control of hazardous energy includes isolating system from its primary power source and residual energy.
the
for
the
5
Is Lockout and Hazardous Energy Control the
Same Thing?
The terms lockout and hazardous energy control are sometimes used interchangeably, but they are
NOT the same thing.
Hazardous energy control is a broad term describing the use of procedures, techniques, designs and methods to protect personnel from injury due to the inadvertent release of hazardous energy.
Lockout is the placement of a lock or tag on an energy-isolating device in accordance with an established procedure. It indicates that the energy-isolating device is not to be operated until removal
of
the lock
or
tag. Therefore, lockout
is
one
way
in
which
hazardous
energy
control
can be
achieved.
6
What is the purpose of a hazardous energy
control program?
In most cases, equipment or systems will have safety devices built in. These safety devices include
barrier guards and safeguarding devices to help protect workers during normal operations. However, during maintenance or repairs, these devices may have to be removed or by-passed. In these situations, a hazardous energy control program is needed.
A hazardous energy control program is used to maintain worker safety by preventing:
•Unintended
•Unintended
•Unintended
release of stored energy.
start-up.
motion.
•Contact
with
a hazard
when
guards
are removed
or
safety
devices
have been
by-passed
or
removed.
7
What must an energy-control procedure
include?
1.
A statement on how to use the procedures;
2.
Specific procedural steps to shut down, isolate, block, and secure machines;
3.
Specific steps designating the safe placement, removal, and transfer of lockout/tagout
devices and identifying who has responsibility for the lockout/tagout devices; and
4.
Specific requirements for testing machines to determine and verify
lockout devices, tagout devices, and other energy-control measures.
the
effectiveness
of
8
What must workers do before they begin
or maintenance activities?
service
1.
2.
3.
4.
5.
Prepare for shutdown;
Shut down the machine;
Disconnect or isolate the machine from the
Apply the lockout or tagout device(s) to the
energy source(s);
energy-isolating device(s);
Release, restrain, or otherwise render safe all potential hazardous stored or residual
energy. If a possibility exists for reaccumulation of hazardous
energy, regularly verify
during
the
service
and
maintenance
that
such
energy
has
not
reaccumulated
to
hazardous levels; and
Verify the isolation and deenergization of the machine.
6.
9
Lockout Process
•
•
•
•
De-energize machinery
Stop equipment using normal procedure
Isolate each source.
Each person must lockout each source of energy. The key(s) must be removed personal control.
Verify isolation of each energy source
and
secured
in
•
•
•
Return controls to “neutral”,
“stop” or
“off ”
positions
after
the verification.
Perform
the required
work.
10
What are the requirements for
devices?
lockout/tagout
Durable enough to withstand workplace conditions. Tagout
devices must not deteriorate or
become illegible even when used with corrosive components such as acid or alkali chemicals
or in wet environments.
Standardized according to color, shape, or size. Tagout devices also must be standardized
according to print and format. Tags must be legible and understandable by all employees.
They must warn employees about
employees clear instruction such as:
Not Energize,” or “Do Not Operate.”
the hazards if
“Do Not Start,”
the machine is
“Do Not Open,”
energized, and offer
“Do Not Close,” “Do
11
What are the requirements for lockout/tagout
devices?
Substantial enough
to
minimize
the
likelihood of
premature
or
accidental
removal.
Employees should be able to remove locks only by using excessive force with special tools
such as bolt cutters or other metal-cutting tools. Tag attachments must be non-reusable, self- locking, and non-releasable, with a minimum unlocking strength of 50 pounds. Tags must be
attachable by hand, and the device for attaching the tag should be a one-piece
tie or its equivalent so it can withstand all environments and conditions.
nylon
cable
Labeled to identify the specific employees authorized to apply and remove
them.
12
Electrical, pneumatic, hydraulic energy
13
14
Tag-out
Tag-out in lieu of Lockout
•
•
Securely attach “locked out” tag in addition to the lock.
If an energy-isolating device is not physically capable
of
being
locked
out,
use
tags
in
place
of
locks.
15
Release from Lockout/Tag-out
When work is complete, re-energize the machine:
Inspect the work area.
Remove locks.
Visually verify that all personnel are clear Re-energize the equipment.
Lock Removal
No one is authorized to remove another person’s lock. Procedures to remove the lock:
The employee’s supervisor verification
An attempt to contact the lock owner
If this attempt is unsuccessful, notify the lock owner.
Evaluate the equipment.
Carry out the ‘Release from Lockout/Tag-out’ procedures.
16
Lock out devices
17
Lock out devices
18
Examples of Tags
19
Any Questions
20