29 CFR 1910.333 is the federal OSHA standard governing safety-related work practices for employees working on or near exposed energized electrical parts in general industry. Its core requirement is simple: circuits must be de-energized before anyone works on them, unless the employer can show that shutting off power would create a greater hazard or is infeasible. Everything else in the standard, from lockout procedures to approach distances to the split between qualified and unqualified workers, flows from that default rule.
Who the Standard Covers
The regulation sorts every worker into one of two categories. A qualified person has been trained to recognize exposed live parts, determine the voltage of those parts, and understand the clearance distances required for the voltages involved. Everyone else is unqualified.1Occupational Safety and Health Administration. 29 CFR 1910.332 – Training
Only qualified persons may work on circuit parts or equipment that have not been de-energized. Unqualified workers can be in the general area, but they cannot perform tasks that put them in contact with exposed live components.2Occupational Safety and Health Administration. 29 CFR 1910.333 – Selection and Use of Work Practices
The standard applies broadly to premises wiring, wiring for connections to supply, connected equipment, and other outside conductors on the premises. If your facility has electrical infrastructure and employees who interact with it, 1910.333 applies.
Training Requirements
Before an employee can be treated as qualified, training must cover three specific skills: distinguishing exposed live parts from other equipment components, determining the voltage of exposed parts, and knowing the clearance distances required for the voltages the employee will work around.1Occupational Safety and Health Administration. 29 CFR 1910.332 – Training
Qualified workers who will make direct contact with energized parts, either with their body or through tools and materials, need additional training on the techniques and protective equipment required under 1910.333(c)(2). Training may be classroom, on-the-job, or a combination, and its depth should match the risk the employee will face.
Unqualified employees still need training on the electrical hazards relevant to their jobs, including the practices in 1910.331 through 1910.335 that apply to their assignments. Unqualified workers learn to recognize and avoid electrical hazards; qualified workers learn to manage them directly.
The Default Rule: De-Energize Before Working
Shut off the power before anyone works on or near exposed live parts. That is the default, not one option among several. An employer may deviate only in two narrow situations: when de-energizing would create a greater hazard, or when de-energization is infeasible due to equipment design or operational limitations.2Occupational Safety and Health Administration. 29 CFR 1910.333 – Selection and Use of Work Practices
The “greater hazard” exception is narrow. It covers things like shutting down life-support equipment, killing ventilation in a hazardous atmosphere, or disabling emergency alarms. Inconvenience or production slowdowns do not qualify, and the employer has to be able to demonstrate the justification.
Circuits operating below 50 volts to ground do not need to be de-energized if there is no increased risk of electrical burns or arc-flash explosions. That conditional matters: low-voltage circuits in certain configurations can still produce dangerous arcs, so the exemption is not automatic.2Occupational Safety and Health Administration. 29 CFR 1910.333 – Selection and Use of Work Practices
Lockout and Tagging Programs
Employers must maintain a written lockout and tagging program describing how energy sources will be isolated before work begins. It must be available for inspection by employees and by OSHA compliance officers.2Occupational Safety and Health Administration. 29 CFR 1910.333 – Selection and Use of Work Practices
Locks and tags must be dedicated to the safety program and not used for any other purpose. Tags must identify who applied them and warn others that the circuit is being serviced. The hardware has to be durable enough to withstand the worksite conditions.
Relationship to 1910.147
Lockout and tagging procedures that comply with 1910.147(c) through (f) are also considered compliant with 1910.333(b)(2), but only if they cover the specific electrical hazards in Subpart S and incorporate two additional elements: the rules about using tags without locks, and the verification testing that a qualified person must perform before work begins.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
Tags Used Without Locks
Locks are preferred because they physically prevent someone from operating a switch. When a tag is used without a lock, the employer must add at least one extra safety measure providing an equivalent level of protection: removing a circuit element, blocking a controlling switch so it cannot be operated, or opening an additional disconnect device. A tag alone is never sufficient because tags warn but do not physically stop re-energization.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
The De-Energization Sequence
The physical process follows a set sequence. The circuit is shut down through its disconnecting device. The authorized worker applies a lock and tag to the disconnect. Before any hands go near the equipment, a qualified person tests the circuit with proper test equipment to confirm it is de-energized.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
The tester must check not only for the expected voltage but also for any voltage that may have been induced by nearby circuits or fed back from connected equipment. For circuits rated above 600 volts, the test equipment itself must be checked for proper operation immediately before and immediately after the verification test.
Stored Energy
Flipping a breaker does not eliminate all electrical energy. Capacitors and other high-capacitance components can hold a dangerous charge after the supply is disconnected. Stored energy must be released, capacitors discharged, and high-capacitance elements short-circuited and grounded before work begins. Any capacitors or associated equipment that must be handled during the discharge process are treated as energized throughout.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
Restoring Power
Locks and tags come off only after the area has been cleared of tools and all employees are positioned safely away from the equipment. The authorized worker must notify everyone who could be affected before re-energizing the circuit.
Working on Energized Parts
When de-energization is genuinely not feasible and the employer has documented the justification, only qualified persons may perform the work. They must use safety practices that prevent contact with energized components, whether directly with the body or through conductive tools or materials.2Occupational Safety and Health Administration. 29 CFR 1910.333 – Selection and Use of Work Practices
Protective equipment requirements come primarily from 1910.335. Workers must be provided with, and must use, electrical protective equipment appropriate for the body parts at risk and the work being performed. That includes insulated gloves, eye and face protection against arcs and flying debris, and nonconductive head protection wherever there is a risk of shock or burns from contact with exposed parts.4Occupational Safety and Health Administration. 29 CFR 1910.335 – Safeguards for Personnel Protection
All tools and handling equipment that could contact energized conductors must be insulated. If the insulation could be damaged during use, an outer layer of protection must cover it, such as leather over rubber insulating material. Equipment must be inspected or tested periodically as required by 1910.137 and cannot be used in a condition that raises doubts about its integrity.
Approach Distances
The regulation sets minimum distances that workers must maintain from exposed energized parts, keyed to voltage and worker qualification.
Qualified Persons
Minimum approach distances from Table S-5, based on the alternating-current phase-to-phase voltage:
- 300 volts and below: avoid contact
- Over 300V to 750V: 1 foot
- Over 750V to 2kV: 1 foot 6 inches
- Over 2kV to 15kV: 2 feet
- Over 15kV to 37kV: 3 feet
- Over 37kV to 87.5kV: 3 feet 6 inches
- Over 87.5kV to 121kV: 4 feet
- Over 121kV to 140kV: 4 feet 6 inches
A qualified person may cross the approach boundary only when properly insulated or when the energized parts are properly insulated from them.5eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices – Table S-5
Unqualified Persons
For overhead lines rated 50kV or below, unqualified workers must stay at least 10 feet away. They also cannot bring any conductive object closer than 10 feet to unguarded overhead lines.6UpCodes. 29 CFR 1910.333 – Selection and Use of Work Practices
Overhead Lines and Vehicular Equipment
Vehicles and mechanical equipment with elevating parts, such as cranes, boom trucks, and aerial lifts, must maintain a 10-foot clearance from overhead lines rated at 50kV or below. For higher voltages, add 4 inches of clearance for every 10kV above 50kV.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
A few situations allow reduced clearance:
- Vehicles in transit with the structure lowered may pass at 4 feet of clearance, with the same 4-inch-per-10kV addition above 50kV.
- If standalone insulating barriers rated for the line voltage are installed between the equipment and the lines, clearance may be reduced to the barrier’s working dimensions.
- When a qualified person uses an aerial lift insulated for the voltage involved, the clearance between the uninsulated portion of the lift and the line may be reduced to the Table S-5 distances for qualified persons.
Each reduction has conditions that must be met before the shorter distance applies.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
Illumination, Confined Spaces, and Conductive Materials
Workers cannot enter a space containing exposed energized parts unless there is enough light to perform the work safely. Employees may not reach blindly into any area that might contain energized parts.3eCFR. 29 CFR 1910.333 – Selection and Use of Work Practices
In confined and enclosed work spaces such as manholes or electrical vaults containing exposed energized parts, the employer must provide protective shields, barriers, or insulating materials to prevent accidental contact. Doors, hinged panels, and similar components must be secured so they cannot swing into a worker and push them into live equipment.
Metal ladders, steel measuring tapes, and similar conductive tools are prohibited near exposed energized components. Portable ladders used where they could contact energized parts must have nonconductive siderails. Conductive jewelry and clothing must be removed or covered where they could contact exposed parts or create a path for current.
Host Employer and Contractor Coordination
When outside contractors perform electrical work at a host facility, both parties share safety responsibilities. Before work starts, the host and contractor must exchange information about site hazards, control measures, and emergency procedures, and repeat the exchange when conditions change.7Occupational Safety and Health Administration. Safety Management – Communication and Coordination for Host Employers, Contractors, and Staffing Agencies
The host must provide enough information for the contractor to assess the hazards its workers will face, including access for site visits and injury records. The contractor must inform the host about any hazards its own work creates and report injuries or safety concerns. Building safety specifications into the contract itself is a practical way to formalize these obligations.
Penalties for Violations
OSHA violations of 1910.333 carry significant financial consequences. For 2026, the maximum penalty amounts remain at their 2025 levels because OSHA did not issue an inflation adjustment:
- Serious violations: up to $16,550 per violation
- Other-than-serious violations: up to $16,550 per violation
- Failure to abate: up to $16,550 per day beyond the abatement deadline
- Willful or repeated violations: up to $165,514 per violation
The failure-to-abate penalty compounds daily. An employer cited for missing lockout/tagout procedures who delays correction can accumulate tens of thousands of dollars in fines on top of the original penalty. State OSHA plans must adopt maximum penalties at least as high as the federal levels.8Occupational Safety and Health Administration. OSHA Penalties
A willful classification means OSHA determined the employer knowingly ignored the standard or showed plain indifference to it. Allowing unqualified workers to perform energized electrical work without PPE is the kind of fact pattern that triggers a willful finding. At $165,514 per violation, a single inspection covering multiple workers or multiple pieces of equipment can produce a six-figure penalty quickly.8Occupational Safety and Health Administration. OSHA Penalties