Understanding the Rules, Risks, and Safer Compliance Methods

Lockout/Tagout (LOTO) is more than a regulatory requirement; it’s a life-saving practice that keeps workers safe from hazardous energy. OSHA estimates that proper LOTO procedures prevent 120 fatalities and 50,000 injuries every year. Despite this, LOTO violations remain in OSHA’s Top 10 most frequently cited standards (1910.147) year after year, with over 2,500 citations in 2024 alone.

So, when exactly is LOTO required, and just as importantly, when is it not?

OSHA’s Rule: Control Hazardous Energy Before Work Begins

The OSHA standard 29 CFR 1910.147, “The Control of Hazardous Energy,” applies whenever employees are performing servicing or maintenance on machines or equipment where the unexpected energization, startup, or release of stored energy could cause injury.

In simple terms:

• If a worker could be harmed by the machine suddenly starting up, LOTO is required.
• If stored energy (electrical, mechanical, hydraulic, pneumatic, chemical, or thermal) could be released unexpectedly, LOTO is required.

Common examples include:

• Repairing or replacing electrical components inside a panel
• Clearing jams in moving equipment
• Servicing pumps, motors, or conveyors
• Performing maintenance on powered industrial machinery

What LOTO Involves

At its core, LOTO requires physically isolating the energy source and applying a lock and a tag to prevent re-energization until work is complete. For electrical work, NFPA 70E Article 120.6 defines seven required steps to establish and verify an electrically safe work condition (plus grounding where applicable).

The steps are:

1. Identify All Energy Sources – Determine all possible sources of electrical supply to the equipment. Review up-to-date drawings, diagrams, and identification tags.
2. Interrupt Load Current and Open Disconnecting Devices – Properly interrupt the load, then open the disconnecting device(s) for each energy source.
3. Visually Verify the Disconnect – Wherever possible, visually confirm that disconnect blades are fully open or that drawout-type circuit breakers are in the fully disconnected position.
4. Release Stored Electrical Energy – Discharge all capacitors and short-circuit high-capacitance elements to ground.
   1. Devices like GracePESDs Voltage Indicators provide visual LED confirmation if voltage is still present when it’s believed to have been released. The LEDs will remain illuminated until all residual energy has fully dissipated, giving workers a clear, touch-safe visual cue before proceeding.
5. Release or Block Stored Mechanical or Other Non-Electrical Energy – Depressurize pneumatic/hydraulic systems, release springs, and restrain or block moving parts.
6. Apply Lockout/Tagout Devices – Use LOTO locks and tags in accordance with your documented procedure. This includes loto locks for securing energy-isolating devices and loto tags to warn against operation.
7. Verify the Absence of Voltage – Use an adequately rated test instrument to confirm the circuit is de-energized, testing phase-to-phase and phase-to-ground. Verify the tester on a known voltage source before and after use.
   1. This step is critical, where PESDs like ChekVolt can make this process safer and faster by allowing verification without opening the enclosure.
8. Optional Step 8 (Where Required) – If there is a possibility of induced voltages or stored energy, apply temporary protective grounding equipment before touching conductors.

When LOTO is Required

LOTO isn’t just a best practice, it’s a regulatory requirement under OSHA 29 CFR 1910.147 and NFPA 70E Article 120 whenever there’s a potential for workers to be exposed to hazardous energy.

You must apply LOTO procedures in situations such as:

• Before any servicing or maintenance is performed on a machine, circuit, or system that could unexpectedly start or energize, ensure that all necessary precautions are taken. This includes both scheduled work and emergency repairs.
• When bypassing, removing, or disabling machine guards that protect against moving parts or electrical contact.
• When working inside electrical enclosures where live parts could be contacted, whether intentionally or accidentally.
• When stored energy could be released unexpectedly, including tensioned springs, compressed air, hydraulic pressure, or charged capacitors.
• During tasks involving both AC and DC systems, including renewable energy applications such as solar, battery storage, and electric vehicle charging systems.

OSHA considers 50 volts or more (AC or DC) hazardous. In fact, OSHA’s interpretation of 29 CFR 1910.303(g)(2)(i) explicitly applies guarding and safe work practices to all live parts operating at 50V or above, regardless of whether the source is alternating or direct current.

NFPA 70E goes further, requiring that voltage be verified before work begins. That means you can’t just rely on a breaker being “off” or a disconnect being open; you must establish and verify an electrically safe work condition following the 7-step process in Article 120.6.

When LOTO is Not Required

There are some limited situations where LOTO is not required, such as certain minor servicing tasks or when equipment is unplugged and under the exclusive control of the worker. But the rules are strict, and exceptions must be applied cautiously.

For a detailed breakdown of situations where LOTO may not be required, see Rockwell Automation’s guide here: When Are Lockout/Tagout Procedures Not Required.

PESDs: Making LOTO Safer and Easier

One of the most critical LOTO steps is Step 7 in NFPA 70E 120.6: “Test for absence of voltage.” Traditionally, this means opening an enclosure and using a handheld meter, exposing the worker to potential arc flash and shock hazards.

PESDs allow voltage presence verification and absence of voltage testing without opening the enclosure:

• Voltage Indicators – Provide continuous LED visual confirmation of voltage presence.
• Safe-Test Point – Thru-door test points for safe meter testing.
• ChekVolt – Combines both a voltage indicator and test points for faster, safer absence of voltage verification.

By integrating PESDs into your panels, you can:

• Reduce exposure to live parts
• Minimize human error in verification
• Improve productivity by reducing procedure times by 45 minutes
• Make compliance with NFPA 70E and OSHA standards the easiest choice

Bottom Line

If there’s a chance a machine or piece of equipment could start up or release stored energy unexpectedly, LOTO is required, and it’s your responsibility to make sure the procedure is followed every time.

With OSHA citing thousands of violations annually, it’s clear that LOTO compliance is still a major challenge for many facilities. But with the right tools, like PESDs, you can make verification faster, safer, and more consistent—without cutting corners.

Want to make your LOTO program safer and more efficient? Download our free eBook: Electrical Safety by Design: Save Lives. Increase Productivity.