Lock Out Tag Out (LOTO)

Hazardous Energy

May 29

A lock and tag have been placed on an energy-isolating device.

Date Posted: 05/29/2024

The release of uncontrolled energy causes thousands of injuries each year. Each year, approximately 3,000 workers suffer lost-time injuries from being caught in dangerous parts of equipment or machinery during maintenance or cleaning, according to Bureau of Labor Statistics (BLS) data. Further, each year, there are approximately 60 fatalities from similar exposures.

What is LOTO?

A lockout tag-out (LOTO) is a set of safety procedures to prevent personal injury or property damage when working with, near, or on machines, tools, or equipment. Also called LOTO procedures, they involve manually adding locks and tags to parts of machines to make all employees aware of the maintenance work and prevent accidents. Employees involved in the lockout tag-out place locks on machines to prevent others from turning the machine on, and they place tags as warning signs of the current maintenance. LOTO aims to protect workers from accidental injury or death caused by unexpected equipment start-up or the release of stored energy. At the same time, maintenance or servicing is performed.

The procedure involves locking or tagging the equipment’s energy-isolating devices, such as switches or valves, and preventing the release of hazardous energy until the work is completed and the equipment is deemed safe to operate again.

What Sorts of Energy Should I be Concerned about in Construction?

According to the Occupational Safety and Health Administration (OSHA), Energy sources, including electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other sources in machines and equipment, can be hazardous to workers. During the servicing and maintenance of machines and equipment, the unexpected startup or release of stored energy can result in severe injury or death to workers. Kinetic and potential are two encompassing forms of energy prevalent in the construction industry.

Kinetic energy sources include:

Electrical
Thermal
Radiant
Sound

Potential energy sources include:

Chemical
Suspended
Pressurized
Magnetic
Mechanical

Due to the potentially catastrophic effects a release of stored energy, isolating devices that prevent the release of energy must be available and used on construction sites. Some examples of these isolating devices are:

Circuit breakers and disconnect switches.
Line valves, blocks, and other devices that can stop or isolate energy.

What is the Difference Between Lock Out and Tag Out?

Lockout and tagout are two distinct procedures used in combination to ensure the safety of workers during maintenance, servicing, or repair work on machinery or equipment. While both methods involve the control of hazardous energy sources, there are some critical differences between lockout and tagout:

Lockout: involves physically isolating the machinery or equipment from its energy source using a lock or other mechanism to secure the energy-isolating device, such as a switch or valve. The lock ensures that the energy source cannot be turned on until the lock is removed by the person who installed it, indicating that maintenance or servicing work is complete.

Tagout: involves using a tag or label to indicate that the machinery or equipment will not be operated until maintenance or servicing work is complete. The tag warns workers that the equipment is not to be used and may include information about the reason for the tagout and the expected completion time.

In general, the lockout is considered the more effective of the two procedures, as it physically prevents the activation of machinery or equipment. On the other hand, Tagout is regarded as a supplementary measure used with lockout to provide additional warning and communication to workers.

LOTO Steps

Prepare for Shutdown: An authorized employee must identify the type of energy, understand the hazards of the energy, and the methods to control the energy before using the LOTO procedure.

Notify Affected Workers: Notify all affected employees that energy will be shut down and locked out for service or maintenance.

Shut down the Tool or Equipment: Shut down the tool or equipment. Follow the details provided in the lockout/tagout procedure. Many tools or equipment have complex, multistep shutdown processes, so following the directions precisely as the procedure lists them is essential.

Disconnect or Isolate the Tool or Equipment: Completely isolate the machine or equipment from its energy sources by using the appropriate energy-isolating devices.

Apply Lock(s) and Tag(s) to the Energy Isolating Device(s): Apply unique lockout/tagout devices to the power sources.

Dissipate Stored Energy: Dissipate stored and residual energy, such as that in capacitors, springs, elevated machine members, rotating flywheels, hydraulic systems, and air, gas, steam, or water pressure.

Check for Stored Energy: Check the tool or equipment for stored or residual energy. Testing instruments, such as voltage detectors or pressure gauges, can be used to confirm energy isolation. These instruments should be calibrated, adequately maintained, and used according to manufacturer instructions.

Restoration: Restoration is the final step in the LOTO safety and procedures. It involves inspecting the work area for completion and safety, removing LOTO devices properly, informing affected employees of equipment status, and restarting. Before restoring equipment, the work area must be inspected for completion and safety. This may involve verifying that all tools and equipment have been removed from the equipment and that the work area is clean and debris-free.