Arc Flash FAQ

What is an arc flash?

An arc flash is a killer electrical explosion caused when an electrical current leaves its intended path and travels through the air from one conductor to another or to the ground.

The explosion arcing fault rapidly heats air molecules, ionizes and vaporizes conductive metal materials and generates the explosion. An arc flash can occur anywhere in an electrical system.

What’s the difference between an arc flash and a flashover?

An arc flash is a flashover. The two terms are interchangeable. Some people also refer to arc flashes as arc blasts.

How dangerous is an arc flash blast?

s1-arcflashOne to two people die from arc flash while another five to ten more are injured, oftentimes critically injured, EVERY DAY.

Other statistics show that:

  • Arc flashes kill within a distance of 10 feet from the blast.
  • Over 2,000 workers go to burn centers each year with electrical-related burn injuries.
  • S. emergency rooms report about 8,000 electrical contact injuries annually.
  • 80% of all electrical injuries are burns from arc flashes igniting flammable clothing.
  • One person, each working day, is electrocuted in the workplace.
  • Approximately 30,000 nonfatal shock accidents occur every year.

How does an arc flash injure people?

People die or are injured by the power of the blast and from the tremendous heat radiated from the explosion. An arc flash, which is four times hotter than the sun, sprays debris in a wide arc, melts clothing, and vaporizes a copper bus.

What type of injuries do people sustain from an arc flash blast?

An arc flash causes horrendous burns, broken bones, hearing loss, brain damage and even death. The severity of the injuries depends on how close a victim is to the blast’s center and on the type of clothing the victim is wearing.

What causes an arc flash?

The four main causes of an arc flash are –

  1. Human error and mistakes, such as mishandling a wire or tool
  2. Unsafe working conditions
  3. Faulty electrical system design or legacy equipment
  4. Negligent preventive maintenance

Besides possible injuries or even death, what other consequences can an arc flash have?

When a company experiences an arc flash, especially if it’s serious or deadly, the company faces Occupational Safety & Health Administration (OSHA) citations, heavy fines, lawsuits, increased insurance rates, a damaged reputation, and business interruption.

Who sets the standards for arc flash prevention?

In 2007, OSHA mandated that businesses implement arc flash standards.  The National Fire Protection Association (NFPA) sets the guidelines for implementing arc flash prevention through its NFPA 70E training manual.

What can an organization do to prevent an arc flash?

Preventing an arc flash involves a number of steps and processes. Assessing risk, conducting an incident energy study, setting an electrical maintenance program in place and proper training (including NPFA 70E training), Should all be part of any preventive maintenance process.