OSHA 29 CFR 1910.147 — the Control of Hazardous Energy standard — governs how the unexpected energization, start-up or release of stored energy must be prevented during servicing and maintenance. This guide breaks the standard down into the parts that actually drive compliance: scope, the written energy control program, the procedure itself, verification, periodic inspection and training.
OSHA 1910.147 covers the servicing and maintenance of machines and equipment in which the unexpected energization or start-up, or the release of stored energy, could harm employees. It does not cover normal production operations, work on cord-and-plug equipment under the exclusive control of the worker, or hot-tap operations that meet specific conditions. Where minor tool changes or adjustments occur during normal production and are routine, repetitive and integral to production, they may fall under an alternative-measures exception only if effective protection is provided.
The cornerstone of the standard is a documented energy control program with three components: written energy control procedures, an employee training program, and periodic inspections. The program must identify every hazardous energy source — electrical, mechanical, hydraulic, pneumatic, chemical, thermal and gravitational — and define how each is isolated and controlled before work begins.
Each machine needs documented, equipment-specific steps unless it meets all eight conditions for a single, simple exception (for example, a single energy source that is readily identified and isolated). The procedure must state the scope, purpose, authorization, rules and techniques for controlling energy, and the means to enforce compliance. Generic, one-size-fits-all procedures are a frequent citation source because they fail to reflect the actual energy sources of the equipment.
A compliant shutdown follows a fixed sequence: (1) prepare for shutdown and notify affected employees; (2) shut down the machine using its normal stopping procedure; (3) isolate every energy source with an isolating device; (4) apply individually-assigned locks and tags; (5) release, restrain or dissipate all stored or residual energy; and (6) verify isolation by attempting to operate the equipment and confirming a zero-energy state before work starts.
Lockout — a physical lock on an energy-isolating device — is the required method whenever the device is capable of being locked out. Tagout alone is allowed only when the employer demonstrates that it provides protection equivalent to lockout, which in practice demands additional means such as removing an isolating circuit element, blocking a controlling switch or opening an extra disconnecting device.
The employer must inspect each energy control procedure at least annually, performed by an authorized employee who is not using the procedure under inspection, and must certify the inspection. Authorized employees who apply locks, affected employees whose machines are serviced, and other employees who work in the area each require training scaled to their role, with retraining triggered by job changes, procedure changes or observed deviations.
Year after year, 1910.147 ranks among OSHA most-cited general-industry standards. The recurring failures are no written, equipment-specific procedure; missing or skipped periodic inspections; inadequate employee training; and incomplete verification of a zero-energy state. A digital energy-control platform addresses each of these by enforcing the procedure, capturing the audit trail automatically and surfacing missed inspections before an inspector does.
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