Lockout/Tagout (LOTO): What OSHA 29 CFR 1910.147 Actually Requires

# What the Standard Covers 29 CFR 1910.147, "The Control of Hazardous Energy (Lockout/Tagout)," applies when employees service or maintain machines and unexpected energization, startup, or release of stored energy could cause injury. OSHA links many citations to procedural gaps rather than equipment defects. The agency estimates proper compliance prevents roughly 120 fatalities and 50,000 injuries a year.

# Required Two narrow exceptions exist. First, cord-and-plug-connected equipment that is deenergized simply by unplugging it, where the plug remains under the exclusive control of the servicing employee. Second, minor tool changes and adjustments during normal production operations—only when the work is routine, repetitive, integral to the production process, and effective alternative protections are used. Treating routine maintenance as "minor servicing" is a common misapplication.

# Written, Machine-Specific Energy Control Procedures OSHA requires written procedures for each machine or piece of equipment outside the narrow exceptions. A generic facility-wide policy is insufficient. Each machine-specific procedure must cover:

• How to shut down the machine and notify affected employees before servicing begins.
• Identification and isolation of every energy source present: electrical, mechanical, hydraulic, pneumatic, chemical, thermal, and gravitational.
• Application of lockout or tagout devices to each energy-isolating device.
• Methods to relieve, restrain, or render safe any residual or stored energy.
• Verification that isolation is effective, typically by attempting to start the machine through its normal controls before work begins.

# Lockout vs. Tagout

# Training Requirements and Employee Categories The standard defines three employee categories with distinct training needs:

• Authorized employees: Those who perform lockout or tagout. They need detailed training to recognize hazardous energy, understand the type and magnitude of energy sources present, and know the specific isolation methods for each machine.
• Affected employees: Those who operate or work near the equipment being serviced but do not perform the lockout. They need to understand the purpose and use of the procedure, not how to execute it.
• Other employees: Those who may be in areas where LOTO is in use. They must know never to start or re-energize equipment that is locked or tagged out.

Employers must certify that training occurred and keep records listing each employee and the training date. Employees who only perform normal production work and encounter servicing under normal machine guarding are trained as affected employees, even if the facility uses tagout elsewhere.

# Periodic Inspections OSHA requires a periodic inspection of each energy control procedure at least once per year. Inspections must be done procedure-by-procedure, not as a single facility-wide review. An authorized employee who is not one of the employees currently using the procedure being inspected must perform the inspection, providing an independent check.

# Practical Focus The standard's enforcement reflects predictable failure modes: missing or incomplete procedures, inadequate training, skipped verification steps, and insufficient inspections. Address those procedural elements directly: document machine-specific steps, prefer lockout where possible, segregate training by role, keep dated training records, and schedule annual inspections for each procedure.