What Is Lockout/Tagout and When Is It Needed?

Companion reading

Verify control of every hazardous energy source

A stopped machine can still contain dangerous energy. Electrical supplies, pressure, elevated parts, springs, heat and other stored energy may remain after an operator presses Stop. Begin with the equipment-specific procedure and the actual servicing task, including nearby systems that can feed energy into the work area.

For covered general-industry servicing, 29 CFR 1910.147 requires an energy-control program with procedures, training and periodic inspections. Authorized employees perform isolation and apply the required controls. Potentially hazardous stored energy must be rendered safe, and isolation and deenergization must be verified before servicing begins. Conditions that permit hazardous energy to build again need continued verification.

An affected employee needs to understand the purpose of the controls and the prohibition on restarting locked or tagged equipment. An authorized employee needs the knowledge and skills for the particular isolation. A tag warns; it is not a physical restraint. Tagout has specific conditions and cannot be selected simply because it is quicker. Electrical work, construction and other sectors also require their applicable rules and employer procedures.

Before the task

• Identify all sources and possible stored-energy release.
• Use the actual equipment procedure and authorized roles.
• Resolve changed conditions, group protection and shift handoffs before proceeding.

Sources and further reading

• 29 CFR 1910.147: Control of hazardous energy ↗

Original companion notes and fictional examples · Updated October 27, 2026. These notes support study; apply the actual workplace procedures and requirements. Government sources retain their own status and do not endorse this material.