6.3 Lockout/Tagout (LOTO) Energy Control (29 CFR 1910.147)

Lockout/Tagout (LOTO) Energy Control (29 CFR 1910.147)

The Control of Hazardous Energy standard, commonly referred to as Lockout/Tagout (LOTO) and regulated under 29 CFR 1910.147, is designed to prevent injuries caused by the unexpected startup, energization, or release of stored energy during the servicing and maintenance of machines and equipment. Servicing activities include tasks such as installing, constructing, adjusting, inspecting, modifying, and maintaining machinery, as well as clearing jams or changing tools where an employee must place their hands or body into a machine's point of operation or hazard zone.

Scope of the LOTO Standard and Types of Energy

The LOTO standard applies to any source of energy that could cause injury to workers. It is a common misconception that LOTO only applies to electrical energy. The standard covers all hazardous energy sources, which include:

• Electrical: Active electrical current from power lines, generators, or batteries.
• Mechanical: Moving parts, gears, belts, or rollers.
• Hydraulic: Pressurized fluid systems (such as jacks or fluid lines).
• Pneumatic: Pressurized air systems (such as cylinders or lines).
• Chemical: Chemical reactions, acids, or toxic gases within piping.
• Thermal: High temperatures from steam, hot water, or furnace elements.
• Kinetic (Motion): Moving parts of a machine that have not come to a complete stop.
• Potential (Stored): Energy stored in elevated heavy parts (gravity), compressed springs, or electrical capacitors.

The standard does not apply to normal production operations unless an employee is required to bypass a guard or other safety device, or place any part of their body into a zone of operation where a hazard exists. Additionally, cord-and-plug connected electrical equipment is exempt from the standard if the plug is completely disconnected from the energy source and remains under the exclusive control of the employee performing the servicing.

The Written Energy Control Program

Employers must establish a written Energy Control Program that consists of three main components:

1. Energy Control Procedures: Documented, machine-specific instructions detailing the exact steps to shut down, isolate, block, and secure each piece of equipment to control hazardous energy.
2. Employee Training: Employers must train workers based on their level of exposure and responsibility. The standard defines three categories of employees:
   • Authorized Employees: These are the workers who perform the servicing or maintenance and are trained to recognize hazardous energy sources, understand the type and magnitude of energy, and execute the steps to isolate and lock out the equipment. Only authorized employees are permitted to apply and remove LOTO devices.
   • Affected Employees: These are workers whose job requires them to operate or use the machine being serviced, or who work in the immediate area where servicing is occurring. They must notify their supervisor or safety officer of any machine issues and understand the purpose of LOTO, but they are never allowed to restart or operate locked-out equipment. They must be notified before LOTO is applied and after it is removed.
   • Other Employees: These are workers whose duties may take them through the area where LOTO procedures are utilized. They must be instructed on the prohibition of restarting or tampering with any lockout or tagout devices.
3. Periodic Inspections: Employers must inspect their energy control procedures at least annually to ensure they are being followed correctly. The inspection must:
   • Be performed by an authorized employee other than the one utilizing the energy control procedure being inspected.
   • Review each authorized employee's responsibilities under the procedure.
   • Identify and correct any deviations or inadequacies in the procedure.
   • Be certified with documentation showing the date, the machine, the employees inspected, and the inspector's name.

The Six Steps of Lockout/Tagout (LOTO)

To safely isolate a machine, the authorized employee must execute the following six steps in the exact sequence specified by the standard:

Step 1: Preparation and Notification

Before shutting down the machine, the authorized employee must locate and identify all sources of hazardous energy, their magnitudes, and the methods required to control them. The authorized employee must also notify all affected employees that the machine is going to be shut down and locked out.

Step 2: Machine Shutdown

Turn off the machine using its normal operating controls (e.g., pressing a stop button, turning a selector switch, or throwing a control lever).

Step 3: Machine Isolation

Operate all energy isolating devices to physically disconnect the machine from its energy sources. This includes flipping electrical disconnect switches, pulling circuit breakers, closing line valves, or blanking off pipes. Note: Push buttons, emergency stop buttons, selector switches, and safety interlocks are control circuit devices, not energy isolating devices, and cannot be used as the primary means of energy isolation.

Step 4: Application of Lockout/Tagout Devices

Attach the lockout and tagout devices to the energy isolating devices.

• A lockout device (typically a padlock) physically holds the energy isolating device in the "safe" or "off" position, preventing anyone from turning it on.
• A tagout device is a prominent warning tag securely fastened to the isolating device, indicating who applied it, when, and warning other workers not to operate the machine.
• Each lock must be key-operated and unique to the authorized employee. No two locks should share the same key, and master keys are prohibited.
• If a device cannot be locked out, the employer may use a tagout-only system, provided they implement additional safety measures that achieve a level of safety equivalent to a lockout (e.g., removing a circuit element, blocking a control switch, or disconnecting a drive shaft).

Step 5: Control/Release of Stored Energy

All stored, residual, or potential energy must be dissipated, relieved, or restrained. The authorized employee must:

• Bleed air pressure from pneumatic lines.
• Drain hydraulic fluid from cylinders.
• Discharge electrical capacitors.
• Release tension on compressed springs.
• Apply mechanical blocks or pins to support elevated parts that could fall due to gravity.
• Vent and flush piping systems carrying steam, hot water, or chemicals.

Step 6: Verification of Isolation (The "Test" Step)

This is the most critical safety step. The authorized employee must verify that the machine is in a zero energy state before starting work. This is done by checking that no personnel are in danger zones, then attempting to restart the machine using the normal operating controls (e.g., pressing the start button). If the machine does not cycle or start, isolation is confirmed.

[!IMPORTANT] CRITICAL RE-OFF STEP: Immediately after testing the controls, the authorized employee must return the operating controls to the "off" or "neutral" position. If they fail to do this, the machine will immediately start up when energy is restored, posing an extreme hazard during the de-isolation phase.

Restoring Equipment to Service (LOTO Release)

When servicing is complete and the machine is ready to be re-energized, the authorized employee must follow these four steps in order:

1. Inspect the Machine and Area: Verify that all tools and non-essential items have been removed, all machine guards are properly reinstalled, and the machine is fully assembled.
2. Check Employee Positions: Ensure that all workers are safely positioned away from the machine's hazard zones.
3. Remove LOTO Devices: Each lockout and tagout device must be removed only by the authorized employee who applied it.
4. Notify Affected Employees: Notify all affected employees that the LOTO devices have been removed and the machine is being re-energized before the power is turned back on.

Special LOTO Procedures

• Group Lockout/Tagout: When multiple workers service the same equipment, they must use a group lockout device (such as a HASP or group lockbox). Each authorized employee must apply their own personal lock to the group device. The equipment cannot be re-energized until the last worker finishes their work and removes their personal lock.
• Shift and Personnel Changes: Written procedures must govern LOTO transfers during shift changes. Typically, the incoming authorized employee applies their lock to the isolating device before the outgoing employee removes theirs, ensuring continuous protection.
• Emergency Lock Removal: If an employee leaves their lock on and departs the facility, only the employer can remove it. This requires a strict, written protocol: verifying the employee is not on site, making all reasonable efforts to contact them, and ensuring they are notified of the removal immediately upon returning to work.