NFPA 70E and NEC Hazard Label Requirements

Published on September 8, 2026 by Staff Writer

A heavy-duty electrical safety switch is mounted on an exterior wall, with labels indicating utility power, the off position, and generator receptacle.

Required information on arc flash labels helps you recognize hazards before equipment examination, adjustment, service, or maintenance while energized. The National Fire Protection Association (NFPA) addresses arc flash labeling requirements in NFPA 70E, Standard for Electrical Safety in the Workplace, Section 130.5(H) of the 2027 edition. This required arc flash safety data helps you select personal protective equipment (PPE) and plan safe work.

Required Label Information for Arc Flashes

Arc flash labels must contain specific information to help you assess the hazards. First, they must list the nominal system voltage. This helps you understand the electrical potential you are dealing with. Next, the label must identify the arc flash boundary. This is the distance from an arc source where incident energy equals 1.2 cal/cm², the threshold associated with the onset of a second-degree burn. You use this boundary to determine where arc flash protective measures are needed.

Additionally, arc flash labeling requirements include at least one of the following:

Calculated incident energy with its corresponding working distance, or an arc flash PPE category from the applicable NFPA 70E tables, but not both.
The minimum arc rating required for clothing.
The site-specific PPE level.

Adding equipment identification helps you match the label to your assessment records. It is a best practice, rather than a minimum label field under Section 130.5(H). Assessment dates are also outside that section’s minimum fields, although the NEC has separate date requirements, as described below.

Clear, accurate labels help you apply NFPA 70E standards and select appropriate protection before work begins.

Label Visibility and Durability

Keeping labels visible and durable helps you read hazard information before approaching the equipment.

Verify that each label matches the equipment and its supporting assessment.
Make markings permanent and clearly visible to qualified persons under the applicable NEC 110.16 requirements. Follow NEC 110.21(B) for durability in the installation environment.
Consider eye-level placement or the front of equipment for easy visibility. These are practical placement recommendations.
Use materials resistant to moisture, chemicals, and UV exposure where those conditions are present.
Review the arc flash risk assessment and supporting label data at least every five years. Update the assessment when system changes could affect its results, and update labels when the information becomes inaccurate.
Standardize label formats across your facility to enhance recognition and understanding.
Ensure labels are easy to read; complex presentation can hinder their effectiveness.

Pro-Tip: Every time you change your electrical system, review the affected arc flash labels. Even small changes can affect incident energy levels and boundaries.
Keep a log of all modifications, no matter how minor. Schedule regular audits to compare your system drawings with what is installed. Use software to track label versions and update dates. Assign one person to oversee label accuracy and compliance. This helps prevent outdated labels from putting you and your team at risk. Train staff to report any changes that could affect arc flash calculations. Make label updates part of your change management process.

Facility and Equipment Considerations

Different facilities and equipment types present different arc flash hazards. Your labeling needs depend on the equipment’s voltage, location, and potential incident energy.

You also need to consider each standard’s scope when planning electrical safety.

NEC and OSHA Requirements

The National Electrical Code (NEC) addresses equipment markings. Check which edition your jurisdiction has adopted, because its requirements differ.

The following comparison distinguishes workplace labeling requirements from installation code requirements.

Requirement Source	Equipment Covered	Labeling Requirements
NFPA 70E, 2027 edition, Section 130.5(H)	Equipment outside dwelling units likely to require energized examination, adjustment, servicing, or maintenance	Provide the hazard information described above.
NEC, 2023 edition, Section 110.16(A)	Covered equipment outside dwelling units likely to require energized examination, adjustment, servicing, or maintenance	Provide an arc flash hazard warning marking.
NEC, 2023 edition, Section 110.16(B)	Service and feeder-supplied equipment rated 1,000 amperes or more, outside dwelling units	Provide an arc flash label following applicable industry practice and include the date the label was applied.
NEC, 2026 edition, Section 110.16	Covered service and feeder-supplied equipment outside dwelling units requiring energized examination, adjustment, servicing, or maintenance	Include voltage, the arc flash boundary, incident energy or the minimum required PPE level, and the assessment completion date. The 1,000-ampere threshold no longer applies.

The 2026 NEC requires the assessment completion date, replacing the label application date specified in the 2023 provision.

The Occupational Safety and Health Administration (OSHA) has separate requirements. Its November 14, 2006 interpretation letter explains that Subpart S does not specifically require arc flash equipment marking. However, 29 CFR 1910.335(b)(1) requires safety signs, symbols, or accident prevention tags where necessary to warn you about electrical hazards. The letter explains OSHA’s position; it does not establish current NFPA 70E label contents.

Installations under exclusive utility control for power generation, transmission, or distribution fall outside NFPA 70E’s scope. For work covered by 29 CFR 1910.269, consult OSHA’s Electric Power Generation, Transmission, and Distribution eTool.

Incident Energy and PPE Selection

Incident energy levels and PPE requirements guide your choice of protection. When your label uses the incident energy analysis method, read the energy value together with the specified working distance. That value describes exposure at that distance; it should not be assumed to describe a task performed closer to the arc source.

For example, when you use the incident energy analysis method, select an arc-rated clothing system whose rating meets or exceeds the calculated exposure at the working distance. Use the assessment to determine the remaining PPE and protective measures for the task.

Clear and accurate labeling helps you understand the potential hazards associated with electrical equipment and select protection for the work you plan to perform.