Free Guide to Arc Flash Labeling - NFPA 70E Compliance & Electrical Safety | LabelMax

This free Arc Flash Guide explains how to properly label energized equipment to comply with NFPA 70E and OSHA standards. Learn the basics of arc flash boundaries, PPE categories, and labeling requirements to keep workers safe and facilities compliant. Perfect for electricians, safety managers, and anyone responsible for electrical safety programs.

1. Understanding
Arc Flash
An overview of arc flash and how to
properly label energized equipment
under NFPA 70E (2018 revision).

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Table of Contents
LabelMax
17475 SW 63rd Ave, Lake Oswego, OR 97035
1-855-484-7266
1Introduction 3
2Keeping Employees Safe 4
3NFPA 70E Timeline 5
4Label Requirements 9
5Arc Flash Labeling Explained 10
6Sample Arc Flash Label 11
7Arc Flash & Shock Boundaries 14
8Creating Arc Flash Labels 15
9IEEE 1584 – Arc Flash Calculation Standard 17
10Summary 19
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Introduction
What is an Arc Flash?
An arc flash is a dangerous electrical
event that occurs when electricity
travels through the air between two
conductors—or from a conductor to a
grounded surface—creating a high-energy
explosion. It’s typically the result of a fault
in an electrical system, such as damaged
equipment, loose connections, or
accidental contact with live components.
During an arc flash, intense heat (up to
35,000°F), bright light, and a powerful
pressure wave (known as an arc blast) are
released in a fraction of a second. This
can cause catastrophic injuries, including
severe burns, hearing damage, lung
trauma, and even death.
Arc flashes often happen when electrical
work is performed on energized (live)
equipment, especially if proper safety
precautions aren’t followed. Common
triggers include removing circuit breakers,
installing fuses, or dropping conductive
tools inside an open panel. Environmental
conditions like dust, moisture, or corrosion
can also increase the risk.
Because of its explosive nature and
extreme danger, arc flash is a major
workplace safety concern—particularly
in industrial, manufacturing, and utility
settings. That’s why safety standards like
NFPA 70E exist: to help employers assess
risks, implement protection strategies,
and ensure equipment is properly labeled
to alert workers to potential arc flash
hazards.

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Keeping Employees
Safe
Preventing arc flash incidents starts with a robust electrical safety program that prioritizes
employee training, the use of appropriate personal protective equipment (PPE), and clear
labeling that identifies the level of arc flash risk.
Comprehensive guidance on these safety measures is available in the NFPA 70E: Standard
for Electrical Safety in the Workplace®, published by the National Fire Protection Association.
Originally developed at the request of OSHA, NFPA 70E serves as a key resource for organizations
seeking to improve electrical safety and reduce the risk of arc flash.
Although OSHA does not explicitly require compliance with NFPA 70E, employers can still be
cited for failing to follow its recommendations. That’s because NFPA 70E is recognized as
an industry consensus standard—outlining the most widely accepted methods for managing
known electrical hazards.
Since arc flash is considered a recognized hazard, employers are legally responsible for
taking reasonable steps to minimize the risk. One of those steps includes applying arc flash
warning labels to inform workers of the potential dangers and help ensure safe decision-
making in the field.
Buy NFPA 70E: Standard for Electrical Safety
in the Workplace
http://catalog.nfpa.org/2015-NFPA-70E-Standard-
for-Electrical-Safety-in-the-Workplace-P1197.
aspx?icid=B484

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1979
First edition of NFPA 70E is published.
1981-1988
Several updated editions of the standard are published, focusing on electric
shock hazards. Sections pertaining to safety-related work practices and safety-
related maintenance requirements are added.
1995
The NFPA 70E standard incorporates arc flash hazards for the first time.
2000
Revisions focus on expanding information about arc flash boundaries and PPE.
2004
The standard’s name changes to its current name, NFPA 70E: Standard for
Electrical Safety in the Workplace
®
.
2009
Annexes are added to the standard that contain information about performing
arc flash incident energy calculations.
2012
The updated standard includes new tables for PPE selection and information
about shock protection boundaries.
2015
Contains a number of important updates pertinent to arc flash.
2018
See next page...
NFPA 70E Timeline

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2015
NFPA 70E Key Updates
The 2015 edition of NFPA 70E, effective August
2014, introduced major changes to improve arc
flash and electrical safety:
JSA Required:
A qualified person must perform a Job Safety
Analysis before maintenance (Article 110.1).
Human Error Added:
Job planning must now consider human error,
per Annex Q.
PPE Management:
Updated guidelines for verifying PPE compliance
(Article 130.7).
Incident Review: Safety programs must include
procedures for investigating electrical incidents.
Terminology Changes:
“Hazard Risk Category” is now “PPE Category.”
Category 0 has been removed.
“Hazard analysis” is replaced with “risk
assessment.”
Boundary Removed: The Prohibited Approach
Boundary has been eliminated.
These revisions promote better risk assessment
and safer work practices across electrical
environments.
6Arc Flash Guide

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2018 NFPA 70E Update
The 2018 edition of NFPA 70E emphasizes human factors in electrical safety—
focusing on reducing risk and improving hazard awareness. Key updates include:
Job Safety Analysis (JSA):
A qualified person must perform a JSA before any maintenance (Article 110.1).
Human Error Consideration:
Planning must account for the possibility of human error, as outlined in Annex Q.
PPE Management:
Enhanced requirements for verifying PPE compliance (Article 130.7).
Incident Investigation:
Safety programs must now include procedures for investigating electrical accidents
These changes reflect a shift toward proactive risk reduction and behavior-based
safety practices.
7Arc Flash Guide

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NFPA 70E – 2024 Edition Highlights
PPE & Labeling:
Arc flash tables and signage guidance revised for clarity and accuracy.
Clearer Structure:
Each article now starts with a scope; definitions centralized in Article 100.
Terminology Tweaks:
“Electric shock” used consistently; “leather protectors” removed to allow newer
PPE materials.
Maintenance Focus:
New Annex S helps assess equipment condition per NFPA 70B.
Improved Job Planning:
JSAs must now include emergency response planning and assess equipment
condition.
PPE & Labeling:
Arc flash tables and signage guidance revised for clarity and accuracy.
ESWC Emphasis:
Stronger requirements for lockout/tagout, voltage testing, and boundary tables
updated for high altitudes.
Program Auditing:
Electrical safety programs must be reviewed every 3 years

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Label Requirements
Arc flash warning labels are required on any electrical equipment that might be serviced
while still energized. This includes gear like panelboards, switchboards, and meter
enclosures.
Every arc flash label must include three key details:
1. System voltage (nominal)
2. Arc flash boundary
3. One of the following:
The available incident energy and the working distance
The minimum arc rating of required clothing
PPE requirements specific to the site

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The main purpose of an arc flash label is
to warn workers about the hazard and help
them choose the right PPE to stay safe on
the job.
The arc flash boundary is the minimum
safe distance from electrical equipment
where a worker could suffer second-degree
burns if an arc flash occurs. This boundary
is based on where the incident energy
reaches 1.2 cal/cm².
Incident energy is the amount of heat
energy released during an arc flash. It
depends on factors like:
System voltage
Available short-circuit current
Arc current
How long it takes protective devices
(like breakers) to shut off the power
To determine the right PPE (personal
protective equipment) for a task, safety
professionals calculate the incident energy
at the typical working distance (usually 18
inches). This information is required on arc
flash labels.
To meet labeling requirements, your label
must include either:
The incident energy at the work location,
or
The PPE Category, along with:
The minimum arc rating of clothing
(shown as ATPV on gear tags)
A list of site-specific PPE required for
the task
Arc Flash Labeling
Explained

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Sample Arc Flash Label
Arc flash labels should follow the ANSI Z535.4 standard for product safety signs. This
includes using a signal word, color, symbol, and text that match the level of hazard.
Use the word “WARNING” (with an orange background) for most arc flash situations to
indicate a serious risk.
Use “DANGER” (with a red background) only when the situation is life-threatening, such
as when incident energy exceeds 40 cal/cm².
The sample label format below is one recommended way to show arc flash information
using ANSI guidelines, but it’s not the only one. Many companies also include shock
hazard details on their arc flash labels to address all electrical risks in one place.
This example includes relevant shock information for a more complete safety notice.








Appropriate PPE Required
Arc Flash Boundary: ………..89 inch
Incident Energy at 18° (cal/cm²): 16.4 Glove Class: ……00
Require PPE: Cotton Underwear + AR Shirt & Pants + AR Coverall + Hearing Protection
ARC FLASH PROTECTION BOUNDARY AND REQUIRED PPE
SHOCK HAZARD PROTECTION BOUNDARIES
Shock Hazard: 480 VAC
Limited Approach: 42 inch Restricted Approach: 12 inch
Equipment ID: Bus C-H Prot: MCB C-H Assessment Date: 8/1/2024

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Label Requirements (2024 NFPA 70E)
Arc Flash Boundary
The minimum distance where someone could receive second-degree burns from an arc
flash. Based on incident energy of 1.2 cal/cm².
Incident Energy & Work Distance
Shows how much heat energy (in cal/cm²) a worker would be exposed to at a standard
distance (usually 18 inches). Helps determine PPE.
Required PPE
Lists the arc-rated gear workers must wear, like gloves, face shields, and flame-resistant
clothing.
OR: PPE Category
Instead of listing incident energy, you can use a PPE Category (1 to 4), based on Table
130.7 of NFPA 70E. Only one method is allowed per label—use either incident energy or
PPE category, not both.
Shock Hazard / System Voltage
Displays the system’s operating voltage (in volts AC) and indicates electric shock risk
from energized parts.
Glove Class (Optional)
Gloves are rated by voltage protection. Class 00 offers the least, and Class 4 offers the
most. Optional but useful.
The following fields reflect the latest 2024 NFPA 70E requirements:

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Label Requirements (2024 NFPA 70E)
Limited Approach Boundary
The distance where electric shock becomes a risk. Only qualified workers—or unqualified
workers under direct supervision—may enter.
Restricted Approach Boundary
A closer distance with higher shock risk. Only qualified personnel using proper PPE and
protection methods may enter this space.
Assessment Date
Arc flash assessments must be reviewed every 5 years or when major changes are
made. Including a date helps track compliance.
Label Guidelines (2024 NFPA 70E)
Labels must be durable and legible for the environment they’re in.
Required on any equipment that may be serviced while energized (e.g., panels,
MCCs, switchboards).
Labels must follow ANSI Z535.4 format, using WARNING (orange) or DANGER
(red) as appropriate.
Label content must use either incident energy or PPE category—not both.
Labels must be reviewed and updated at least every 5 years.

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The Limited Approach and Restricted Approach boundaries are related to electric shock
hazards, not arc flash. However, it’s still useful to understand where they fall in relation to
the Arc Flash Boundary.
Depending on the equipment and conditions, the arc flash boundary may be located
inside or outside the limited approach boundary.
Any worker entering these boundaries must be properly trained and wear the required
PPE based on the type of hazard—shock or arc flash.
Arc Flash & Shock
Boundaries
Arc Flash
Boundary
Limited
Approach
Boundary
Restricted
Approach
Boundary
Prohibited
Approach
Boundary
Exposed
energized
conductor or
circuit part
Restricted
Space
Limited
Space
Prohibited
Space

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Creating Arc Flash Labels
There are several acceptable ways to determine what information goes on an arc flash
label. Employers can:
Use software to calculate incident energy
Refer to calculation methods in NFPA 70E appendices
Follow the IEEE 1584-2018 arc flash calculation guide
Hire an electrical engineering firm to perform a study
Regardless of the method used, it’s the employer’s responsibility to ensure labels are
created accurately and placed on the correct equipment.
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Common Ways to Get Arc Flash Labels
1. Order Pre-Made Labels
Pros: No equipment needed
Cons: Expensive per label, long lead times, not ideal for frequent use
This option works for low-volume needs. Some suppliers offer custom printing, while
others sell generic labels with blank fields for manual entry.
2. Print Labels on Paper (Inkjet/Laser)
Pros: Low cost, easy to use with existing office printers, on-demand printing
Cons: Not durable; requires lamination or protective covers
Useful for temporary labeling or internal documentation, but not suitable for harsh
environments or long-term use.
3. Print with a Thermal Transfer Printer (Recommended)
Pros: Durable, chemical- and water-resistant, ideal for high-volume and permanent
labeling
Cons: Requires a thermal printer and compatible label supplies
This is the most reliable method for compliant, long-lasting arc flash labels in industrial
settings.

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IEEE 1584
Arc Flash Calculation Standard
IEEE 1584 is the industry standard for calculating arc flash hazards. It provides formulas
to determine how much incident energy could be released during an arc flash and what
PPE is needed to protect workers. First published in 2002, it has helped prevent serious
injuries and equipment damage across many industries.
2018 Updates - Key Enhancements
After more than a decade of additional testing—including nearly 2,000 arc flash
experiments—the IEEE released an updated version of the standard in 2018. This version
provides more accurate and flexible models for real-world conditions.
What Stayed the Same
Applies to 3-phase systems from 208 V to 15,000 V
What’s New or Improved
Short-Circuit Current Range
208–600 V: 500 A to 106,000 A
601–15,000 V: 200 A to 65,000 A
Conductor Gap
208–600 V: 0.25 to 3 inches
601–15,000 V: 0.75 to 10 inches
Working Distance
Calculations require a minimum of 12 inches

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2018 Updates - Key Enhancements
Electrode Orientation Matters
In the 2002 version, only vertically arranged electrodes were tested. The 2018 update
found that electrode position significantly affects arc behavior:
Horizontal electrodes: Arc plasma moves outward, away from the equipment
Vertical electrodes: Arc plasma hits barriers and may concentrate toward the enclosure
opening
The 2018 update includes multiple electrode configurations to better reflect actual
equipment layouts and improve accuracy in energy calculations.
Expanded Voltage Modeling
The updated model uses specific test points (600 V, 2700 V, and 14,300 V) and applies
interpolation to calculate values for in-between voltages with greater precision.
Grounding Differences Removed
Earlier versions separated results for grounded vs. ungrounded systems. The 2018 model
uses a more stable arc simulation, so there’s no longer a need to differentiate. Calculations
now apply uniformly, regardless of grounding configuration.

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Summary
IEEE 1584 (2018) remains the most accurate and widely used method for
arc flash hazard calculations. It is fully supported under 2024 NFPA 70E, and
its improved modeling ensures better protection for workers through more
precise incident energy estimates and PPE guidance.

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