OSHA 1926.404(b)(1) GFCI Rules for Construction Sites

Check the protection method before writing a GFCI notice

Which protection method does the employer use?

Confirm GFCIs under 1926.404(b)(1)(ii) or an assured equipment grounding conductor program under (iii). No visible plug-in GFCI alone does not establish a violation.

Does the outlet fall within the GFCI provision?

Check voltage, phase, amperage, employee use and whether it is temporary rather than permanent building wiring. Check the specific generator exception in the official text below.

Is there an assured grounding program?

Check the written program, designated competent person, inspections and test records. A missing color sticker alone is not conclusive: records can use logs or other effective means.

These checks explain the federal provisions quoted below. Review state-plan differences for the project’s jurisdiction.

Official text

29 CFR 1926.404(b)(1)(i) Wiring design and protection

(b)(1)(i) General. The employer shall use either ground fault circuit interrupters as specified in paragraph (b)(1)(ii) of this section or an assured equipment grounding conductor program as specified in paragraph (b)(1)(iii) of this section to protect employees on construction sites. These requirements are in addition to any other requirements for equipment grounding conductors.

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29 CFR 1926.404(b)(1)(ii) Wiring design and protection

(b)(1)(ii) Ground-fault circuit interrupters. All 120-volt, single-phase, 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, shall have approved ground-fault circuit interrupters for personnel protection. Receptacles on a two-wire, single-phase portable or vehicle-mounted generator rated not more than 5kW, where the circuit conductors of the generator are insulated from the generator frame and all other grounded surfaces, need not be protected with ground-fault circuit interrupters.

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29 CFR 1926.404(b)(1)(iii) Wiring design and protection

(b)(1)(iii) Assured equipment grounding conductor program. The employer shall establish and implement an assured equipment grounding conductor program on construction sites covering all cord sets, receptacles which are not a part of the building or structure, and equipment connected by cord and plug which are available for use or used by employees. This program shall comply with the following minimum requirements: (A) A written description of the program, including the specific procedures adopted by the employer, shall be available at the jobsite for inspection and copying by the Assistant Secretary and any affected employee. (B) The employer shall designate one or more competent persons (as defined in § 1926.32(f)) to implement the program. (C) Each cord set, attachment cap, plug and receptacle of cord sets, and any equipment connected by cord and plug, except cord sets and receptacles which are fixed and not exposed to damage, shall be visually inspected before each day's use for external defects, such as deformed or missing pins or insulation damage, and for indications of possible internal damage. Equipment found damaged or defective shall not be used until repaired. (D) The following tests shall be performed on all cord sets, receptacles which are not a part of the permanent wiring of the building or structure, and cord- and plug-connected equipment required to be grounded: (1) All equipment grounding conductors shall be tested for continuity and shall be electrically continuous. (2) Each receptacle and attachment cap or plug shall be tested for correct attachment of the equipment grounding conductor. The equipment grounding conductor shall be connected to its proper terminal. (E) All required tests shall be performed: (1) Before first use; (2) Before equipment is returned to service following any repairs; (3) Before equipment is used after any incident which can be reasonably suspected to have caused damage (for example, when a cord set is run over); and (4) At intervals not to exceed 3 months, except that cord sets and receptacles which are fixed and not exposed to damage shall be tested at intervals not exceeding 6 months. (F) The employer shall not make available or permit the use by employees of any equipment which has not met the requirements of this paragraph (b)(1)(iii) of this section. (G) Tests performed as required in this paragraph shall be recorded. This test record shall identify each receptacle, cord set, and cord- and plug-connected equipment that passed the test and shall indicate the last date it was tested or the interval for which it was tested. This record shall be kept by means of logs, color coding, or other effective means and shall be maintained until replaced by a more current record. The record shall be made available on the jobsite for inspection by the Assistant Secretary and any affected employee.

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What it requires, in plain English

Where the employer uses the GFCI option, approved personnel-protection GFCIs cover the temporary 120-volt, single-phase, 15- and 20-ampere receptacle outlets in employee use, subject to the specific generator exception below.
Receptacles on a two-wire, single-phase portable or vehicle-mounted generator rated not more than 5kW, with circuit conductors insulated from the frame and all other grounded surfaces, don’t need GFCIs.
An assured equipment grounding conductor program needs a written description at the jobsite, one or more designated competent persons, and a visual inspection of cord sets and cord-and-plug equipment before each day’s use.
Program tests are done before first use, after repairs, after suspected damage, and at intervals not over 3 months (6 months for cord sets and receptacles that are fixed and not exposed to damage), and are recorded.

Where it shows up on site

Extension cords run from a building outlet with no GFCI in line
A temporary power spider box with a damaged or missing GFCI
Cord sets with no current color code or tag on a site that runs an assured grounding program

Verify on site before you call it

A photo rarely shows every fact a standard depends on. Confirm these in person before treating the condition as a violation:

Is the outlet part of the permanent building wiring, or temporary construction power?
Is the circuit 120-volt, single-phase, 15 or 20 amperes?
Is the power from a two-wire, single-phase generator rated not more than 5kW with conductors insulated from the frame, which is exempt?
Does the site rely on GFCIs or on a written assured equipment grounding conductor program, and who is the designated competent person?
When were the cord set and tool last tested, and does the log or color code show it?

Typical corrective actions

Take the cord set or tool out of use until it is on GFCI-protected power or verified under the assured grounding program.
Install a GFCI at the receptacle, in the panel or as a portable in-line device, and test it before use.
Inspect cord sets and cord-and-plug equipment for external defects and keep damaged items out of service until repaired.
Where the site uses an assured grounding program, confirm the written program is at the jobsite and test records are current.

A worked corrective action notice

Illustrative wording for a fictional site. Adapt it to verified conditions; it is not a completed inspection or an OSHA citation.

Observed condition: A cord-connected tool is supplied from a temporary distribution box. No GFCI device is visible in the photograph.
Verify before issuing: The photograph does not establish upstream protection, circuit ratings or whether an assured equipment grounding conductor program is in use.
Requested correction: Have the responsible electrical contractor verify and document the applicable protection method before the equipment is used. Keep damaged or defective equipment out of use pending correction.
Recipient’s reply: Identify the outlet and equipment, describe the protection verified or correction made, and attach the relevant test record and an after-photo. “GFCI installed” alone does not identify what was checked.
Closeout check: Verify the actual supply and the documented protection method on site. A photograph of a device cannot prove that it operates correctly.

Use the free fillable notice and reply template to record the condition, responsible company and due date. See a complete notice-to-closeout example or how a subcontractor replies.

Common questions

Which outlets need GFCI protection on a construction site?

Under 1926.404(b)(1)(ii), all 120-volt, single-phase, 15- and 20-ampere receptacle outlets that aren’t part of the permanent wiring of the building or structure and are in use by employees. The employer may instead use an assured equipment grounding conductor program under (b)(1)(iii).

How often are cords tested under an assured equipment grounding conductor program?

Before first use, before return to service after repairs, after any incident that could have caused damage, such as a cord set being run over, and at intervals not over 3 months. Cord sets and receptacles that are fixed and not exposed to damage may go up to 6 months. Each cord set is also visually inspected before each day’s use.

Related standards

This guide summarizes federal OSHA construction standards for general information. It is not legal advice. States with their own OSHA-approved plans may set different or additional requirements; see federal and state coverage.