Skip to main content

Arc Flash Incidents (What They Are, Causes, Injury Costs, & How to Avoid Them)

What is an Arc Flash?

An arc flash is an electrical explosion. Think of each piece of energized electrical equipment as bombs with the varying potential of severity if it were to blow.

An arc flash occurs when the insulating medium, like an electrical insulator, no longer offers sufficient resistance to the flow of electric current. If enough electrical energy is present, this arc will ionize the air surrounding it, causing a traumatic and explosive event. 

The temperature of arc flash incidents is what makes them so deadly. They can reach 20,000 °C, which is over 3 and a half times hotter than the surface of the sun!

The size of the arc flash will depend on what overcurrent protection there is. And when there’s not enough energy to result in a huge explosion, “small” arc flash incidents happen, which can still cause fires, burn injuries from molten metal, blindness, and hearing damage. 

To give you an idea of what an arc flash looks like, take a look at the image below to see the blast. 

What Causes an Arc Flash?

An arc flash can be caused by either equipment or human-related factors (or both). 

Below are some of the main instigators of an arc flash:

  1. Human error (e.g., dropping metal tools into the circuit or panel enclosures)
  2. Equipment failure (e.g., a failed contactor)
  3. Inadequately rated electrical test instruments (e.g., a “Wiggy” or an inexpensive digital meter with inadequate fusing)
  4. Poor craftsmanship (e.g., loose wire nuts or incorrect terminations)
  5. Pest control issues (e.g., spider webs or rodents crossing phase conductors)

The Electricity Forum suggests arc flash incidents happen all the time in the United States. Somewhere between 5-10 arc flash explosions occur each day, although there could be many more. Most go unreported. 

Worried about an arc flash? Hire an arc flash expert, like Herzig Engineering, to complete an arc flash analysis

Analyses can be conducted for facilities across the nation and all types of industries: food processing, manufacturing, hospitals and healthcare, and more. 

Request a quote for your own arc flash analysis. Or call (816) 734-8300

Is an Arc Flash Fatal?

Yes, an arc flash can be fatal. Around 400 fatalities occur as a result of arc flash incidents per year. But not all incidents kill. 

The report went on to estimate that those incidents resulted in an average annual total of 7,000 burn injuries and 2,000 hospitalizations. So while not every incident is fatal, there can still be damage to human life. 

Non-Fatal Arc Flash Incidents

Non-life threatening arc flash injuries can include, but are not limited to:

  • Severe burns to the skin – An arc flash’s temperatures can be more than three times hotter than the sun. The intense heat can cause significant burns to an employee’s body, even when they are several meters away from the incident. 
  • Internal burns after inhalation of hot vapor – The heat can also create gasses that can cause burns in the mouth, throat, and lungs if inhaled. Molten metal can lodge onto the person’s skin or cause serious internal damage if ingested. 
  • Hearing damage – Noise levels from the blast can measure up to 160 decibels, which is more than enough to rupture a person’s eardrums.
  • Eye damage, including blindness – The ultraviolet light that is emitted when the flash occurs can cause what is known as flash blindness. This is similar to a sunburn on the eye.
  • Bodily damage due to the ejection of materials and hazard of shrapnel – Which is anything that didn’t melt but the blast pressure wave would fling out at us. Also, clothing can melt on their skin or be set on fire, which is why it’s so important to purchase the necessary PPE to minimize the risk of harm.

How Much Could an Arc Flash Incident Cost a Business? 

Arc flash incidents and hospitalization costs can easily cost a business anywhere between $200,000 to $750,000. And at worst, some direct AND indirect costs can surpass $15.75M.

A business is typically liable for:

  1. All hospital costs
  2. Legal fines
  3. Emotional distress fines
  4. Disability 

That’s if your business is found to be at fault.

A metal smelting company faced fines of $278,456 in penalties in June 2019 after three workers faced severe burns because of an arc flash incident. 

There are also indirect costs to consider with arc flash incidents. These include:

  • Increased insurance premiums
  • Repair costs
  • The cost of replacement workers
  • Court costs
  • New equipment costs

Your business might also suffer losses because of a dent in your reputation and a loss of business opportunities if clients steer clear from your business because of the incident. 

Avoid arc flash incidents and expensive fines by hiring an expert! Request a quote for your own arc flash analysis. Or call (816) 734-8300.

How Do You Prevent an Arc Flash?

The most effective method to prevent an arc flash is to call an electrical safety engineer to conduct an arc flash study. The state of your electrical systems will then be assessed, and you will be alerted to any issues that need attention. 

This is just one step you can take towards arc flash mitigation, but there is more you can do.

Further steps include:

  • Train employees. It is necessary to train your employees in safe work practices in relation to those that are listed in OSHA guidelines and the instructions provided by the NFPA. The more trained they are, the better, as this will reduce the chances of negligence and mistakes when working with your high-powered machinery. 
  • Ensure equipment is properly installed. Make sure any equipment is installed in accordance with applicable industry codes and standards and the manufacturer’s recommendations.
  • Perform a risk analysis (No evidence of impending failure). Where could electrical hazards occur? Consider this within your workplace, then check for faulty equipment, arcing, overheating, loose wiring, visible damage, deterioration, and other aspects of your business where there could be the risk of an arc flash.
  • Use signage and labeling. Labeling is part of the arc flash study, but you can also provide labeling and signage to indicate where risks may exist. Labels and signage should be included on power panels, power lines, high-voltage machinery, and any other dangerous electrical components that are within the workplace. 
  • De-energize equipment. You should establish an ESWC in order to de-energize equipment operating at 50V or greater before maintenance work begins on any of your electrical systems.
  • Properly maintained equipment. The equipment has been maintained in accordance with the manufacturer’s recommendations and applicable industry codes and standards. An appropriate electrical preventative maintenance (EPM) program is key to reducing the risk of equipment failure that could have the potential of blowing out and harming anyone unfortunate enough to be in the area. 
  • Familiarize yourself with regulations: These include OSHA, NFPA 70, NFPA 70E, and IEEE 1584
  • Install arc fault detection devices. These can provide some protection from arc faults. Speak to an electrical engineer for more guidance on these. 
  • Personal Protect Equipment. PPE won’t prevent an arc flash, but it will protect your employees who may be at risk of injury. You should provide PPE for any employee that could be at risk within the roles they carry out for your business. When it comes to electrical tasks, PPE should include face shields, arc-rated clothing, arc flash gloves, arc flash hoods, and arc suppression blankets. 

Are You Electrical Safety Compliant? 

Are you reducing your risk and creating a safer, more efficient workplace? Download our free electrical safety checklist. Self-assess your electrical safety program to see how much you’re at risk.


Another equally important thing is to implement an electrically safe work condition or ESWC.

To establish an ESWC, the worker must complete 8 steps:

  1. Determine sources
  2. Open disconnects 
  3. Visually verify
  4. Release stored electrical energy
  5. Release or block stored mechanical energy
  6. Apply lockout/tagout (LOTO)
  7. Verify the absence of voltage phase to phase and phase to ground with “triple test.” 
  8. Apply temporary protective grounding equipment as needed.

Establishing an ESWC before performing electrical tasks is the best way to prevent injuries, fatalities, and equipment loss from an arc flash.

What Should You Do After an Arc Flash?

Here are the steps we recommend when helping someone after an arc flash occurs:

  1. Call 911 immediately! 
  2. If the person is still in contact with the electrical source, do not touch them!
  3. Turn off the electricity (if you can’t do that, use non-conductive materials and try to remove the victim from the electrical source).
  4. If there are burns, run cool (but not cold water) over the affected area and then cover with a dry, clean cloth after the skin has cooled. Never apply ice or any type of ointment.
  5. If they are on fire, smother or douse the flames with a fire extinguisher. Don’t attempt to remove any melted clothing from the person, as this is likely to cause further damage.
  6. If they are unconscious, perform CPR if they aren’t breathing or if they don’t have a pulse.
  7. If the person is conscious, be aware that they may have spine or neck injuries. For this reason, do not ask them to move.

No matter how the person is after the incident, if there are apparent injuries or not, we’d recommend calling 911. 

Summary

You might think the chance of an electrical arc flash is low, especially if you haven’t detected faults within your electrical equipment.

However, don’t take the risk. Arc flash incidents happen more than you think. And of those incidents, around 10% end in a fatality. 

The severity of an arc flash is major. They can kill or injure your employees, and your business could face great financial losses. 

Act now and do what you can to protect your business and the people that work within it. Provide training, do regular risk assessments, find ways to protect both your electrical equipment and your employees, and if you haven’t yet done so, book an arc flash study. 

At Herzig Engineering, we provide electrical safety consulting, training, and system studies to reduce risk and create a safer, more efficient workplace.

By completing an arc flash study with us, you’ll avoid expensive fines & fees, reduce risk & increase output, and keep employees safe & happy. 

Request an electrical safety quote today, so you stay compliant!