OSHA 1910.334 is the federal workplace safety rule that tells employees how to use electrical equipment safely on the job — inspecting cords before each shift, keeping grounding pins intact, staying out of wet conditions with unapproved gear, not resetting a tripped breaker without investigating, and pulling damaged equipment out of service. It sits in Subpart S of OSHA’s general industry regulations and focuses on day-to-day equipment use rather than how wiring is designed or installed.1Occupational Safety and Health Administration. 29 CFR 1910 Subpart S – Electrical
Who Has to Follow It
The rule reaches every employee who works on, near, or with electrical installations in a general industry workplace. OSHA splits those workers into two groups. A qualified person has training and demonstrated skill in the construction and operation of electrical equipment and understands the hazards. An unqualified person has little or no such training.2Occupational Safety and Health Administration. Qualified Employee Requirements for the Servicing and Maintenance of Electrical Equipment
The distinction runs through the whole standard. Testing live circuits is reserved for qualified persons. The basics — inspecting cords, avoiding wet conditions, taking damaged equipment out of service — apply to everyone.
Portable Electric Equipment and Cords
Most of 1910.334 deals with cord-and-plug equipment and extension cords, because those are what employees touch most often and where most electrical injuries in ordinary workplaces come from.
Inspecting Before Each Shift
Every portable cord-and-plug device and every extension cord must be visually inspected before use on each shift. The inspection looks for external defects — loose parts, deformed or missing pins, damage to the outer jacket or insulation — and for signs of internal damage such as a pinched or crushed cord.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
There is one exception. Equipment and extension cords that remain plugged in after their initial placement and are not exposed to damage don’t need to be re-inspected until they are moved.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment A desktop computer under a desk fits. A portable grinder that travels between job sites does not.
Handling and Grounding
Flexible cords cannot be used to hoist or lower equipment. The weight and motion can pull conductors loose inside the cord and create a fault that isn’t visible from the outside. Cords also cannot be fastened with staples or hung in ways that damage the jacket or insulation.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Equipment that uses a grounding-type plug must have a flexible cord with an equipment grounding conductor. Altering a plug or receptacle in any way that breaks the continuity of the grounding path is prohibited. The classic violation is snapping the third prong off a plug to fit a two-slot outlet. That defeats the grounding system and turns a routine equipment failure into a possible electrocution.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Wet and Conductive Locations
Water and electricity together lower the threshold for a fatal shock. Under 1910.334(a)(4), portable electric equipment and flexible cords used in highly conductive locations — areas flooded with water or other conductive liquids — must be approved for those conditions. “Approved” means listed or labeled by a nationally recognized testing laboratory for use in that environment.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Employees may not plug or unplug cords with wet hands when energized equipment is involved. And if an energized plug or receptacle connection is itself wet — a cord connector that has been submerged, for example — it can only be handled with insulating protective equipment.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Opening Circuits and Resetting Tripped Breakers
When a circuit is carrying current, it can only be opened, closed, or reversed with load-rated switches, circuit breakers, or other devices specifically designed as disconnecting means. Cable connectors that aren’t rated for load-break, fuses, terminal lugs, and cable splice connections may not be used to switch load, except in an emergency.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
When a breaker trips or a fuse blows, the standard prohibits simply flipping it back on or replacing the fuse until someone has determined the circuit and equipment can be safely re-energized. Repeatedly resetting a tripped breaker or replacing blown fuses without investigating the cause is specifically forbidden.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
There is a practical exception. If the circuit design and the overcurrent device make clear that the trip was caused by a temporary overload rather than a fault, the circuit can be re-energized without a full examination.
Test Instruments
Only qualified persons may perform testing work on electrical circuits or equipment. Before use, every test instrument and its associated leads, cables, power cords, probes, and connectors must be visually inspected for external defects and damage. Anything compromised gets pulled from service.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Test instruments and their accessories must also be rated for the circuits they will be connected to and designed for the environment where they will be used. Putting a multimeter rated for 600 volts on a 4,160-volt system, or using an instrument not rated for a wet industrial setting, violates this provision.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment
Removing Damaged Equipment From Service
Whenever an inspection or use reveals a defect or damage that could expose an employee to injury, the item must come out of service immediately. No employee may use it until repairs and tests have been completed to make it safe.3Occupational Safety and Health Administration. 1910.334 – Use of Equipment The regulation doesn’t prescribe a specific tag or label; the requirement is that the item is pulled and stays out of anyone’s hands until it’s fixed and verified.
Penalties and Common Citations
OSHA enforces 1910.334 through workplace inspections, complaint investigations, and follow-up visits. Violations are graded by severity, and fines are adjusted annually for inflation. As of 2025, the maximum penalty for a serious violation is $16,550 per instance. Willful or repeated violations carry a maximum of $165,514 per violation.4Occupational Safety and Health Administration. 2025 Annual Adjustments to OSHA Civil Penalties
Common citations include failure to inspect cords before each shift, use of equipment with missing grounding pins, and operating unapproved equipment in wet locations. These are typically classified as serious because the hazard is immediate: a single defective cord or missing ground pin can deliver a lethal shock. Employers who ignore the standard after a first citation face repeat-violation penalties that reach six figures quickly.