The increased use of machinery running on high-voltage current magnifies the potential for an arc flash incident that could harm or kill workers. Here are five PPE tips to reduce your workers’ risk during an arc flash incident.

Arc flash exposure can kill given the extreme heat and blast force. Learn how to best use PPE to reduce the risk of harm for your workers.

The thing that will likely stand out about arc flash safety is that the Occupational Safety and Health Administration’s focus is not about prevention.

“We’re the only trade where OSHA is concerned about minimum injury and not preventing injury,” explains Bill Nolte, a master electrician who manages electrical safety services and training for Martin Technical.

Under OSHA’s requirements, “a second-degree burn is an acceptable injury,” Nolte says. But one in 20 workers exposed to an arc flash may suffer a worse or catastrophic burn, he adds.

“I don’t know a single electrician who has never been shocked,” Nolte says.

Once a safety team understands that, it can take steps to do a few things to help keep its workers safe and put the odds in its favor that an employee doesn’t become the one in that statistic.

What Is an Arc Flash Hazard?

At its most basic, an arc flash—which has the potential to achieve heat levels of roughly four times the surface of the sun (or 35,000 degrees Fahrenheit)—occurs when an unexpected electric discharge travels through the air between conductors or from a conductor to a ground. 

The potential harm comes from the extreme heat. It can vaporize metal and lead to a massively forceful blast of plasma and molten metal. 

But the distance—or impedance—from the energy source and the voltage of the device emitting the discharge play into the potential harm. The greater the current, the more damage possible; but, the greater the impedance, the less potential damage likely.

Clearly, on a metalworking shop floor, there’s potential for an arc flash incident to be exacerbated by induction furnaces, sharp objects and the thermal energy created as workers cut and form molten metal.

“There are so many energy sources in machinery that you can’t limit your thinking only to electrical,” Nolte says. “Missing one can get you hurt or possibly killed.”

Learn about the value of optimizing your lockout/tagout procedure for electrical design in “5 Arc Flash Protection Tips for a Better Fire Safety Plan.”

Arc Flash Calculations for PPE Selection: Incident Energy Method vs. Table Method

“Arc flash PPE selection is based solely on incident energy, as determined by arc flash risk assessment calculations or tables in NFPA 70E, Article 130,” Nolte says.

But electrical safety is complex, Nolte says. That’s why all arc flash PPE products carry labels based on the ability to protect at a specified level of exposure and all arc flash labels provide detailed information about its voltage and current levels.

Even so, it’s an area of expertise that many metalworking and manufacturing businesses need help with to do successfully, he says.

Although there are limitations to the table method, it was never intended that field personnel perform all of the steps to use the tables in NFPA 70E Article 130, Nolte says. And, performing arc flash risk assessments by the calculation method yields potentially less, or lower levels of PPE, though they are based on a plant’s specific risks, he says.

“I’m a firm believer in doing the arc flash study, but not a firm believer in following the recommendations on the labels dictated, because they’re going to protect to a minimum level and a second-degree burn,” he says.

Go deeper. Read “Standards Spotlight: The Most Crucial Changes in NFPA 70E 2018.”

What Are OSHA’s Regulations for Arc Flash Compliance?

There is no specific stand-alone OSHA standard dealing with arc flash protections. The federal agency includes its requirements for arc flash personal protection in 29 CFR 1910.335, under Subpart S Electrical. It also instructs companies to refer to the National Electrical Code, NFPA 70, and NFPA 70E, the Standard for Electrical Safety in the Workplace.

The National Fire Protection Association released a new version of the full code this year and is about to adjust 70E as well. But, Nolte points out, OSHA has not made any changes to its requirements to reflect these updates.

In addition to the 1910 specification and the NFPA regs, protecting workers from hazardous arc flash incidents comes under OSHA’s General Duty Clause, 5(a)(1). It essentially stipulates that all businesses must maintain a work environment that keeps their workers out of harm’s way so as to prevent injury or death. It applies to arc flash safety efforts specifically because there is no stand-alone standard.

It’s still important to understand that OSHA will issue a violation based on the NFPA standards and expects that businesses will implement appropriate PPE for employees who work on or manage electrical equipment.

The chief way to achieve compliance is through the use of the PPE and labeling. Nolte shares five ways to improve worker safety using arc flash PPE.

If you need arc flash PPE, here’s a safety selector to help you compare products.

5 Arc Flash Safety Tips Using the Best Practices in PPE

1. Double the incident energy level as expressed in cal/cm2.

Given the fact that the minimum specifications can result in a second-degree burn, whatever a label identifies as the use distance from the potential arc flash source, double it.

“That immediately helps protect you,” Nolte says.

2. Use light clothing in warmer climates.

There’s a tendency to use PPE that’s all dark in color. But if your business is south of the Mason-Dixon Line, you’ll want light-colored arc-rated clothing to reduce heat fatigue, Nolte advises. Your employees will be more likely to don and keep the PPE on.

The one exception: The rubber gloves should be black. “It’s not known why, but they protect better from arc flash than other colors,” he says.

3. If you rent your uniforms, be sure to check tags, glue and thread.

Uniforms should never have patches or tags that have been attached using hot glue or sewn on using nylon thread. Both immediately invalidate any arc rating because the glue and nylon thread will melt immediately upon exposure to an arc flash.

Many companies rent uniforms, which is completely acceptable, but you should not assume that the rental companies will know or follow PPE arc-rating requirements, Nolte says. What’s more, companies often glue name tags on uniforms right over the wearers’ hearts, he adds.

4. If you buy uniforms, launder them per the care instructions.

Manufacturers must attach a care label, Nolte says, that notes:

  • Never wash with other non-arc-rated garments, as a flammable layer of lint will be deposited on the garments.
  • Never use bleach, chlorine or oxygenating products, as they may damage the fabric’s chemical treatment.
  • Never use starch, as this will leave a flammable layer on the garment.
  • Never exceed the maximum water temperature, as this could damage the fabric’s chemical treatment.

​5. Provide training every year.

The OSHA rules specify that all qualified employees must have safety training every three years. Nolte recommends that training be two days in length and that refreshers be done annually.

“We all forget what we don’t use all the time,” he says.

How does your team evaluate its arc flash PPE needs: incident energy survey or table calculations?

Talk to Us!

Leave a reply

Your email address will not be published. Required fields are marked *


Signing into Better MRO is easy. Use your username / password, or register to create an account. We’ll bring you back here as soon as you’re done.

Redirecting you in 5 seconds