Electrical Safety

Don’t Let Arc Flash Cost You

A maintenance supervisor at a Wisconsin iron foundry was severely burned by an electrical arc flash in June 2013. The supervisor was injured while servicing a 480-volt circuit breaker without proper electrical protective equipment. The Occupational Safety and Health Administration (OSHA) cited the employer for a willful violation of electrical standards, alleging that the employer failed to ensure protective equipment was used while the circuit breaker was being operated with the cover removed.

OSHA also cited the employer for seven other serious electrical safety violations, including failing to implement safety-related work practices and use protective shields, barriers, and insulating materials to protect employees performing energized tasks; failing to conduct inspections and tests of machinery and insulating rubber gloves; reenergizing circuits before determining that conditions were safe to do so; and a lack of training in safety-related electrical work practices.

Following electrical safety practices could have prevented this worker’s injury. Read more to learn how to avoid a similar incident at your workplace.

What is Arc Flash?

Arc flash occurs as a result of an electrical arcing fault. The current flows through ionized air, which causes energy to dissipate, producing intense heat and light. Arc flashes often result in an arc blast, which occurs when the surrounding air is heated. The temperature rises dramatically and an explosion results.  While arc flashes and arc blasts are distinct, arc blasts can only occur because of an arc flash (a useful analogy would be the relationship between lightning and thunder).


Join us on Tuesday, September 1, for our in-depth webinar, OSHA Citations: When and How to Contest Them to Maximize the Benefit to Your Company


What Damage Results from Arc Flash?

Every day in the United States, between 5 and 10 arc flash explosions occur. Arc flash incidents can damage equipment and cause fatalities and severe injuries, including burns, hearing loss, nerve damage, and cardiac arrest. More than 2,000 people a year are treated in burn centers for related injuries. An arc flash incident can result in 6 to 8 months of lost work time. More serious injuries can end a worker’s career or even cost a life.

Then there’s the cost. According to one expert, the average medical expense for an employee who survives an arc flash is $1.5 million. The price of litigation and settlement in arc flash cases is between $5 million and $10 million.


It can be a paralyzing moment when an OSHA inspector knocks at your door. How should you react? Should you welcome the inspector in or lock the door and get your lawyer on the phone? Click here to learn more!


What Causes Arc Flash?

Causes of arc flash incidents include:

  • Inadvertent contact, as when workers drop tools on conductors, circuit breakers, or other energized parts;
  • Improper work procedures, such as working on energized equipment when it should have been de-energized or locked out;
  • Loose connections;
  • Insulation failure;
  • Buildup of dust, impurities, and corrosion on insulating surfaces;
  • Short surges in voltage;
  • Malfunction of circuit interruptions, which causes the fuse or breaker to explode; and
  • Animals, such as squirrels and snakes, which enter electrical equipment seeking warmth.

Tomorrow, we’ll discuss how to prevent arc flash.