What is an arc flash and what causes it?

An arc flash is a short circuit through air that flashes over from one exposed live conductor to another conductor or to ground.

Arc Flash There are many different ways an arc flash can occur, including:

  • Coming close to a high-amp source with a conductive object can cause the electricity to flash over
  • Dropping a tool or otherwise creating a spark can ignite an arc flash
  • Equipment failure due to use of substandard parts, improper installation, or even normal wear and tear
  • Breaks or gaps in insulation
  • Dust, corrosion, or other impurities on the surface of the conductor

OSHA Requirements and the NFPA 70E Standard

The National Fire Protection Association (NFPA) details how to comply with the Occupational Safety and Health Administration's (OSHA) regulation, 29 CFR 1910.333(a), through the NFPA 70E standard.

According to the NFPA 70E standard, there are six primary responsibilities that facilities must meet. These responsibilities include:
  • Training for employees
  • Written safety program in place that is actionable
  • Personal Protective Equipment (PPE) available for employees
  • Insulated tools
  • Arc flash hazard degree calculations
  • Properly labeled equipment
The NFPA 70E 2015 edition requires employers to conduct an arc flash risk assessment to determine the amount of thermal energy that could be generated from an arc flash incident. The information is then used to define a flash protection boundary around the potential source, and to determine the level of arc-rated apparel and other personal protection equipment required when employees cross the boundary while they work on or near explosive live parts.

The NFPA 70E Standard updates every three years. Learn about the changes between 2012 and 2015 here!
Arc Flash Symbol

Are you complying with the 2015 NFPA 70E Standard?

Our safety services experts have targeted and evaluated key areas of the 2015 NFPA 70E Standard. Take our Arc Flash Safety Check Up to see if your program is at risk.

Arc Flash Safety Checkup

Arc Flash Boundaries

Exposed Conductor, or Circuit
RESTRICTED Approach Boundary
(distance at which there is increased danger of shock)
LIMITED Approach Boundary
(distance at which employees could be exposed
to a shock hazard)
ARC FLASH Boundary
(furthest established boundary from the energy source where
heat generated could result in burns)

Arc Flash Risk Assessments 

Arc Flash Risk Assessment An arc flash risk assessment is done for many reasons, some of which are as follows:

  1. To prevent worker injury or death
  2. To minimize equipment damage
  3. To minimize system downtime
  4. To comply with codes and safety regulations
  5. To meet insurance requirements
  6. To avoid litigation expenses


If you're interested in seeing what a world class arc flash risk assessment includes, or if you'd like to see an example of the type of assessment Brady Safety Services can create for you, download our Risk Assessment Sample Report.

Arc Flash Printer

Arc Flash Labeling Requirements & Examples

Arc flash labeling is the responsibility of the employer, not the manufacturer or installer of the equipment. Labeling is required for any piece of electrical equipment that is likely to require examination, adjustment, service or maintenance while energized, creating the potential for an arc flash incident to occur.

View Arc Flash Label Requirements and Examples

Brady Safety and Software Services

Our Safety and Software Services team takes a proactive approach to Arc Flash Safety from NFPA requirements to best practices and beyond. To learn more about arc flash services visit our Safety and Software services website.

Arc Flash Label Printers

Arc Flash BBP30  Printer

Brady offers top-of-the-line label printers capable of taking care of arc flash label printing and many other industrial labeling applications. With built-in arc flash label applications and up-to-code label materials, you can simply make any arc flash label you may need, when you need it.

Shop Arc Flash Label Printers

Pre-Printed Arc Flash Labels

Arc Flash Warning Label

Looking for standard or stock arc flash safety messaging? Shop for pre-printed arc flash labels here. Write-on labels are also available so you can fill in your equipment specific information.

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