Arc flash is a short circuit through air caused by a flashover between exposed live conductors or to ground. Arc flash incidents are common, costly, and increasing in reported accidents. Arc flashes can be caused by proximity to high-amp sources, sparks from tools or equipment failures, breaks in insulation, or impurities on conductors. Most electrical burns come from arc flash, not shocks. Approximately 350 people are killed by electricity annually in the workplace, with around 50% related to arc flash. Proper training, risk analysis, and personal protective equipment are needed to understand and mitigate arc flash hazards.

1. What is Arc Flash?
Arc flash is a short circuit through air
that flashes over from one exposed live
conductor to another conductor or to
ground. Arc flash incidents are common
and costly, and the frequency of reported
accidents is increasing. This is why arc
flash has become a very hot topic within
MSHA & OSHA.

2. What Causes Arc Flash?
Arc flashes can be caused in a variety of ways:
• Just 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.

3. How Common Is Arc Flash?
• In the past, if someone suffered burns in an electrical
accident, people thought the burns were caused by the
electrical shock passing through the body. Electrical
shocks can cause burns. But what research has shown is
that most burns from electrical accidents actually come
from arc flash.
• The majority of hospital admissions due to electrical
accidents are from arc flash burns, not from electrical
shocks. Of the approximately 350 persons killed in the
work place by electricity last year, roughly 50% were
related to arc flash. A report by Capelli-Schellpfeffer, Inc.,
estimates that 5-10 arc flash explosions happen in the
USA every day, resulting in 1 to 2 deaths per day.
• That figure only in takes into account incidents where
victims were sent to special burn centers. The
number does not include cases sent to regular hospitals or
clinics, nor unreported cases or near misses.

4. Safety Facts
• Fact: Almost 8000 electrical contact accidents
occur in the U.S. each year.
• Fact: At least One worker dies each day from
electrical contact.
• Fact: Fatalities from electrical accidents with a
potential arc flash component have been
trending downward since recent mandatory safe
work practices have become “law.”

5. Training
• Do you and your employees know the risks?
Knowing the level of potential hazard is critical to
taking the proper level of precaution.
• Fact: Everyone at risk of arc flash needs a basic
understanding of:
 Risk Analysis
 Arc Energy Theory
 How to determine safe working distances
 Required PPE.

9. ARC FLASH EVENT
NFPA / NEC 70E ARC FLASH
PROTECTION

10. © ABB
2/07/2012 | Slide 10
5 KV 1200 Amp Breaker
Racking
Handle

11. © ABB
2/07/2012 | Slide 11
Residual
Damage
Behind
Where the
Person was
Standing

12. © ABB
2/07/2012 | Slide 12
Residual
Damage
Above the
Gear

13. 40
Cal/cm2
Arc
Flash
Suit
© ABB
2/07/2012 | Slide 13

14. © ABB
2/07/2012 | Slide 14
40
Cal/cm2
Flash
Hood