Overview
29 CFR 1910.147, "The Control of Hazardous Energy (Lockout/Tagout)," is the OSHA standard that governs how employers must protect workers from hazardous energy during equipment servicing and maintenance. The standard applies to general industry and covers the servicing and maintenance of machines and equipment where unexpected energization, start-up, or release of stored energy could cause injury.
The standard is organized into six sections: scope and application (a), definitions (b), general requirements (c), application of control (d), release from lockout/tagout (e), and additional requirements (f).
Section (a): Scope and Application
The standard applies to the servicing and maintenance of machines and equipment where workers may be exposed to hazardous energy. It requires employers to establish a program and utilize procedures for controlling hazardous energy with lockout or tagout devices.
What's Covered
Any servicing or maintenance activity where a worker could be exposed to unexpected energization or release of stored energy. This includes constructing, installing, setting up, adjusting, inspecting, modifying, maintaining, and servicing equipment. It also covers lubrication, cleaning, unjamming, and tool changes where exposure exists.
Key Exceptions
- Normal production operations: Routine use of a machine for its intended production function is excluded, unless the worker must remove or bypass a guard or place any part of their body into a danger zone.
- Cord-and-plug equipment: Exempt when unplugging the equipment controls the hazard and the plug remains under the exclusive control of the servicing employee.
- Hot tap operations: Welding on pressurized equipment to install connections is exempt when documented procedures and special equipment provide proven effective protection.
Section (c): General Requirements
This is the largest and most prescriptive section of the standard. It establishes requirements for the entire energy control program.
Energy Control Program (c)(1)
Employers must establish a program consisting of energy control procedures, employee training, and periodic inspections. This is not optional. Every covered employer needs all three components.
Lockout vs. Tagout Selection (c)(2)-(3)
If an energy isolating device is capable of being locked out, the employer must use lockout. Tagout alone is permitted only when the device physically cannot accept a lock, or when the employer demonstrates that tagout provides full equivalent protection. Demonstrating equivalence requires additional safety measures beyond the tag itself.
Energy Control Procedures (c)(4)
Procedures must be developed, documented, and utilized for each piece of equipment. Each procedure must include:
- A specific statement of intended use
- Specific steps for shutting down, isolating, blocking, and securing the machine
- Specific steps for placement, removal, and transfer of lockout/tagout devices
- Requirements for testing and verifying the effectiveness of energy controls
There is one narrow exception: a documented procedure is not required when all eight conditions in (c)(4)(i) are met simultaneously (single energy source, no stored energy, single lock achieves full isolation, exclusive control, no hazard to others, and no accident history). In practice, documenting every procedure is the safer approach.
Protective Hardware (c)(5)
The employer must provide locks, tags, and other hardware. Devices must be singularly identified, used only for energy control, standardized by color/shape/size, durable enough for the work environment, and clearly identifying the employee who applied them.
Periodic Inspections (c)(6)
Every energy control procedure must be inspected at least annually. The inspection must be performed by an authorized employee who is not the one routinely using the procedure. Certifications must record the machine or equipment, inspection date, employees included, and the person performing the inspection.
Training (c)(7)
Training must be role-specific:
- Authorized employees: Recognition of hazardous energy sources, type and magnitude of energy, and methods for isolation and control
- Affected employees: Purpose and use of the energy control procedure
- Other employees: Awareness of the procedure and prohibition on restarting equipment
When tagout is used, all employees must be trained on tag limitations: tags are warnings only (no physical restraint), tags must not be removed without authorization, and tags may create a false sense of security. Retraining is required when job assignments change, when equipment or procedures change, or when inspections reveal knowledge deficiencies. All training must be certified with employee name and dates.
Section (d): Application of Control
This section prescribes the specific sequence for applying lockout/tagout. The steps must be followed in order: preparation (know the energy sources), shutdown (orderly stop), isolation (operate all energy isolating devices), lock/tag application (affix devices), stored energy (relieve and restrain), and verification (confirm zero energy state). See our complete LOTO guide for detailed coverage of each step.
Section (e): Release from Lockout/Tagout
Before removing locks and tags and restoring energy:
- Inspect the work area to ensure nonessential items are removed and components are operationally intact
- Verify all employees are safely positioned or removed from the area
- Notify affected employees that devices are being removed
- Each device must be removed by the employee who applied it
There is one exception to the removal rule: when the applying employee is unavailable, another person may remove the device if the employer has developed specific procedures for this situation, verified the employee is not at the facility, made reasonable efforts to contact them, and ensured the employee knows the device was removed before they resume work.
Section (f): Additional Requirements
Testing and Positioning (f)(1)
If locks must be temporarily removed to test or position equipment, a specific sequence applies: clear the area, remove employees, remove devices, energize and test, then deenergize and reapply controls before resuming work.
Outside Personnel (f)(2)
When contractors perform servicing, the on-site and outside employers must inform each other of their respective LOTO procedures. The on-site employer must ensure its employees understand and comply with the contractor's program.
Group Lockout (f)(3)
When multiple workers service the same equipment, a group lockout procedure must provide equivalent protection to individual LOTO. Primary responsibility vests in one authorized employee, and each worker must affix their own personal device to a group lockbox.
Shift Changes (f)(4)
Specific procedures must ensure continuity of protection during shift and personnel changes, including orderly transfer of LOTO responsibility between off-going and oncoming employees.
Penalties for Non-Compliance
LOTO violations carry significant penalties. Serious violations can exceed $15,000 per instance, and willful or repeated violations can reach $156,000 or more. Beyond fines, OSHA can issue citations that require immediate corrective action, and criminal penalties apply when a willful violation results in a worker death.
