Arc Flash PPE: The Definitive Guide


blog author iconJon Travis
date icon2021 / 11 / 30
blog views icon5244
Arc Flash PPE: The Definitive Guide

This is the ultimate guide to arc flash PPE.

So, if you’re looking for:

  • What makes up a PPE Kit
  • Understanding the category levels
  • How the ratings work
  • How to select the proper PPE for the job
  • Steps to properly inspect before use
  • How to care for and maintain your PPE
  • A helpful buyer’s guide
  • and more.
  • Then you are in the right place!

Let’s get started.

 

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What is Arc Flash PPE?

Arc flash personal protective equipment (PPE) is a combination of clothing and safety equipment worn for protection from arc flash and shock hazards by a person performing electrical work.

Primarily, arc flash PPE is divided into the following subgroups:

  • Head, face, neck and chin protection
  • Eye protection
  • Hearing protection
  • Body protection
  • Hand and arm protection
  • Foot and leg protection

All arc flash apparel and equipment must be given a specific arc rating to ensure that it meets or exceeds the hazard levels present where the work is to be performed.

Using PPE to Protect Yourself from an Arc Flash.

There are many ways to protect yourself from an arc flash, but quite often your only option will be to use electrical arc flash PPE.

Ensuring you are covered head to toe with equipment that is properly rated is paramount to your safety.

In order to understand the arc rating, you first need to understand what it is correlated to…

The incident energy value.

Incident energy is the amount of heat energy produced by the arc flash explosion.

Typically, it’s measured in calories per square centimeter (cal/cm2).

So let’s say you are standing in front of 30 amp disconnect (600 volts) and an arc flash occurs.

You would be exposed to a certain amount of heat energy.

Let’s just say we worked it out and it was 3.7 cal/cm2.

As long as your arc flash gear had a arc rating higher than 3.7 cal/cm2 then you will be protected from the arc flash.

But how do you determine the arc rating?

Keep reading to find out.

How to Determine the Arc Flash Rating

In order to determine the arc rating of a given material, you have to send it for laboratory testing.

Basically, they blow up the clothing or equipment in a lab and see if it passes the test.

What’s the test?

This depends on the type of personal protective equipment you are trying to get rated.

Each type of protection has its own standard (or standards) for testing that it must meet.

Here are the main ones:

  • ASTM F1506 (arc rated apparel)
  • ASTM F2178/F2178M (arc rated face shields)
  • ASTM F2675/F2675M (arc rated gloves)
  • ASTM F1891 (arc rated rain gear)

During the testing, there are two things that can happen that determine the results of the test and therefore determine the arc rating.

At certain incident energy, you will either reach the material’s Arc Thermal Performance Value or its Breakopen Threshold Energy.

Whichever one comes first dictates the number that goes on the equipment’s tag. 

Usually, it’s the arc thermal performance value or ATPV Rating.

What is ATPV Rating?

When you are performance testing arc flash apparel you expose the material to a certain amount of heat energy.

We call that the arc flash incident energy.

The arc thermal performance value (ATPV) is the material’s ability to withstand the incident energy.

How do you determine the atpv rating?

The value is determined by the amount of incident energy required to transfer enough heat through the material to create a 50% probability that the person wearing the ppe will experience the onset of a second degree burn.

What?

Yup, sounds crazy but this is how it works.

So… let’s say you are in an arc flash that is has an incident energy of 8 cal/cm2.

And you are wearing clothing that is rated 8 cal/cm2 (because the ATPV was 8).

Now what?

Well… now there is a 50% chance that you will experience the onset of a second-degree burn.

This means the skin under your clothing is exposed to about 1.2 cal/cm2.

What is EBT Rating?

Another factor in performance testing your arc flash gear is determining when it will break open.

Break open is defined as a hole that’s either has an area of 16 mm2 or an opening of 25 mm in length.

The breakopen threshold energy (EBT) is similar to the ATPV…

It’s the amount of incident energy that would result in a 50% chance that breakopen occurs.

What’s the Difference Between AR & FR?

AR stands for arc rated.

FR stands for flame resistant.

All arc rated garments are flame-resistant, in fact, that’s the barrier to entry.

In order to even send a material to be tested for an arc rating, it must first meet the requirements of FR clothing standard (ASTM D-6413).

Then once it passes that test it can be sent to see if it passes the AR tests (from ASTMF 1506).

Not every garment will pass both so remember this one thing.

All arc rated clothing is flame resistant; but not all flame resistant clothing is arc rated.

When is Arc Flash PPE Required?

Trying to figure out when arc flash PPE should be worn is not as straight forward as you might think.

But I’ve got a nice way you can approach it.

There a 4 steps to a basic risk assessment:

  1. Identify the hazards
  2. Estimate the severity
  3. Estimate the likelihood of occurrence
  4. Determine your mitigation technique

Step 3 is by far the most important step!

Here’s why.

Step 1 and 2 almost always have the same answers for any electrical work.

The hazards are arc flash and shock and the severity is high (or high enough that we don’t want it to happen to us without PPE).

So really it boils down to estimating the likelihood of occurrence.

Luckily in both CSAZ462 and NFPA70E they have a table that estimates the likelihood of occurrence for you.

Simply go to that table, find the job you are doing, and if the likelihood is a “yes” then you’ll need to wear arc flash PPE.

Voila!

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How to Select Your Arc Flash PPE

Once you’ve completed your arc flash risk assessment and you know the likelihood of occurrence is high enough to warrant PPE you’ll need to select something suitable for the hazard.

There are two methods you can use to select the proper PPE for the job.

  1. The incident energy analysis method
  2. The arc flash PPE category method

The first method is always preferred as it takes the guesswork out of it for the electrical worker.

But, in reality, there is much more equipment out there that is not labelled so that’s why you will also need to understand the second method.

I’ll go through each one in detail so you can understand more about them and what you have to consider before making your choice.

The Incident Energy Analysis Method

The incident energy analysis method requires an arc flash study to be done on the equipment in order to determine the hazard levels.

Once you have the arc flash study completed you will have labels on each piece of equipment.

On those arc flash labels will be all kinds of information required to perform the task safely but most importantly will be the incident energy.

Getting to this point will require time and resources but it will be well worth it!

At this point, determining the PPE required is easy.

Simply look at the arc flash label, find the incident energy and then make sure all of your arc flash gear is rated higher than the incident energy shown on the label.

That’s it!

Easy.

The Arc Flash PPE Category Method

The arc flash PPE category method uses tables that can be found in CSAZ462 and NFPA70E.

They use different numbering systems so I will refer to them by their titles.

First, you will need to reference the table titled “arc-flash ppe categories for ac systems” (or dc systems). 

Choose the equipment type and voltage you are working on.

Equipment types to choose from  are:

  • panelboards
  • motor control centers
  • switchgear (metal-clad and arc-resistant)
  • switchboards
  • motor starters
  • other equipment

Available voltages to choose from are from 240 V up to 15 kV.

Here’s the catch (and why this method is a little more difficult).

You then need to look at the parameters for the equipment type you chose and make sure your system falls within this criteria.

Parameters:

  • available fault current
  • maximum fault clearing time
  • minimum working distance

If the system you are working on does not fall within the parameters described in the table then you must use the incident energy analysis method.

If it does, then simply look beside the equipment and it will tell you the category number (1 through 5).

At this point, you can go to the next table titled “personal protective equipment (PPE)”.

Each category corresponds with a minimum arc rating for the PPE.

These are the different arc flash levels of protection:

  • Category 1 (4 cal/cm2)
  • Category 2 (8cal/cm2)
  • Category 3 (25 cal/cm2)
  • Category 4 (40 cal/cm2)
  • Category 5 (75 cal/cm2)

At this point, things are pretty much the same as the incident energy analysis.

The table will list out all the possibilities of apparel to wear but as long as you have your entire body covered in the appropriate PPE then you will be fine.

Just make sure that once you hit category 3 you realize that you can no longer wear the arc flash face shield… you need to go to the hood.

What is Contained in an Arc Flash Suit Kit?

Now it’s time to build your arc flash kit!

But what are all the components you’ll need?

You’re going to want to try to simplify as much as possible so one thing I recommend is going to a two-part simplified approach.

This will give you an “every-day” kit rated 12 cal/cm2 and a “once-in-a-while” kit rated 40 to 100 cal/cm2 (depending on how high the arc flash levels get at your workplace).

Let’s start with the 12 cal kit.

This will be more important because you will be using it 90% of the time.

The 12 cal arc flash kit includes:

  • arc rated face shield
  • arc rated balaclava
  • arc rated long-sleeve shirt and pants (or coveralls)
  • rubber insulating gloves with leather protectors
  • class E hard hat
  • safety glasses
  • ear canal insert hearing protection
  • leather footwear

Next, you’ll need to choose your “once-in-a-while” 40 or 100 cal suit kit.

The 40 cal arc flash suit kit includes (or 100 cal):

  • arc rated suit hood
  • arc rated suit jacket
  • arc rated suit pants
  • rubber insulating gloves with leather protectors
  • class E hard hat
  • safety glasses
  • ear canal insert hearing protection
  • leather footwear

And that’s it!

Now we will go through all the different types of arc flash ppe and go over all the things you need to know about each one.

What is Arc Rated Clothing?

Arc rated clothing consists of the apparel used to cover your torso, arms, and legs.

The clothing has been tested against the ASTM F1506 standard and is given either an ATPV or EBT value (whichever is lesser)…

This is the arc rating (in cal/cm2).

Arc rated clothing is by far the most important part of an electrician’s arc flash gear.

The survival rate from burn injuries drops significantly as the percentage of your body burned goes up.

This clothing covers the majority of your body, so that means, less of you gets burned and your chances of survival is much higher.

What is Arc Flash Clothing Made Of?

Arc flash clothing is made of either a fabric that has inherently FR fibers (such as modacrylic fibers or aramid fibers) or a non-FR fabric (such as cotton or cotton-nylon blend) which has been chemically treated to provide FR properties.

The advantage to using inherently FR fibers is that the FR properties are part of the fibers natural design and cannot be washed away or worn out.

How to Wash Arc Flash Clothing?

To wash arc flash clothing at home follow these tips:

  1. Wash clothing at least once per week as dirt, oil and other contaminants can effect the FR properties of the clothing. 
  2. Ensure all hooks and fasteners are closed on the clothing (if washing an arc flash hood, remove the faceshield and inner-helmet first).
  3. Select warm water temperature as this is best for colored garments that are heavily soiled (do not use hot water).
  4. Use a mild detergent (most general commercial detergents for colored clothing are fine).
  5. Select “Delicate or Hand Wash” cycle in order to reduce wear-and-tear on the clothing and an extra rinse cycle as well.
  6. Tumble dry at low temperatures or line dry (but keep not in direct sunlight).

Do not use bleaching agents or products that contain bleaching agents.

Do not wring the clothing out.

Do not use an iron on the arc flash clothing.

Arc Flash Shirts

Arc flash shirts come in a variety of styles and colors but ultimately need to perform one task.

This task is to protect a person’s torso and arms (down to the wrists) from an arc flash.

Most arc rated shirts will have an arc rating around 8 cal/cm2.

Here are some worth taking a look at:

mwg arc rated shirt

mwg comfort weave 9.0 cal

skanwear arc flash shirt

strata arc corporate 8.5 cal

pmmi arc rated t shirt

pmmi c54 long sleeve 8.0 cal

Arc Flash Pants

Arc flash pants are designed to protect the worker's legs.

Typically, they will have a higher arc rating than the matching shirt (usually around 12 cal/cm2)

Here are some we recommend:

 

mwg arc rated pants

mwg flexguard 8.5 cal

 

strata arc flash pants

strata hi-viz 9.9 cal

 

mwg arc flash pants

mwg duck canvas 18 cal

Arc Flash Coveralls

Because arc flash coveralls protect the body from the wrists, to the neck, and then down to the ankles they are a better option than the shirt and pants combination.

Arc rated coveralls are typically rated higher than the shirt and pant combo but can range from 8 cal/cm2 up to 25 cal/cm2.

When shopping for arc flash coveralls keep an eye out for these brands:

oberon arc flash coveralls

oberon inherent fr 12 cal

pmmi arc flash coveralls

steel grip coveralls 20 cal

skanwear arc flash coveralls

strata arc global 10 cal

Arc Flash Rain Gear

Sometimes electrical work is performed outside and the weather is not always favorable. 

This is where arc flash rain gear comes in handy.

Arc rated rain gear testing is very similar to arc flash clothing but must also meet the requirements of the ASTM F1891 specification which calls for the material to be exposed to twice the arc rating to ensure no melting or dripping will occur.

Arc flash rain gear is designed to protect you from the elements as well as the arc flash hazard.

pmmi arc flash rain gear

pmmi arc extreme 9.2 cal

mwg arc flash rain gear

mwg stormshield 10 cal

strata arc flash rain gear

strata hi-viz waterproof 24 cal

Arc Flash & Cotton Underwear

A question that comes up a lot is “what do I wear for underwear with my arc flash clothes?”.

The most practical answer is cotton (with a small amount of elastic material).

When exposed to a direct flame, 100% cotton will burn, but the key factor is that it will not melt.

Underneath your arc flash protection, the cotton underwear will stay safe from the flames and will not catch fire and the small amount of elastic material in the waistband is considered negligible by most experts.

Some companies do have arc flash underwear available and would be considered an upgrade to cotton underwear.

pmmi arc flash cotton underwear

pmmi control bottoms 4.0 cal

skanwear arc flash cotton underwear

skanwear arc boxers 6.3 cal

mwg arc flash cotton underwear

mwg flexsafe 4.3 cal

Head, Face, Neck & Chin Protection

Once you have your arc flash clothing figured out it’s time to protect your most important asset…

Your head.

You’ve really got two options:

  1. Arc rated faceshield with balaclava
  2. Arc flash hood

Let’s look at each piece.

Arc Flash Face Shield

The arc flash face shield is designed to protect your face from the radiant heat energy of an arc flash as well as your eyes from the blinding light produced during the incident.

It’s not designed to protect you from projectiles (although most times it will)…

So you’ll have to keep wearing your safety glasses underneath.

Arc rated face shields will need to be worn with a class E hard-hat and an arc rated balaclava to protect the rest of your head.

As far as I know these are the two most trusted brands of face-shield on the market…

Paulson and Oberon.

paulson arc flash face shield

paulson

oberon arc flash face shield

oberon

Arc Flash Balaclava

The arc rated balaclava goes with the face shield and is responsible for protecting the rest of your head from the arc flash (the part that the shield doesn’t protect).

The balaclava is usually designed with a similar fabric to the clothing and is essentially an arc rated ski-mask.

Typically, the balaclava is rated 12 cal/cm2 but I’m sure you can find higher.

Trouble is, if you are following the industry standards then the option to wear the AR faceshield and balaclava is only available up to 12 cal/cm2…

After that you need to go to the hood.

arc rated balaclava

oberon balaclava 12 cal

arc flash balaclava

skanwear balaclava 6.5 cal

AR balaclava

pmmi balaclava 12 cal

Arc Flash Hood

The arc flash hood is essentially the same technology as the face shield and balaclava but with one key difference.

Instead of being pressed against your skin, the arc flash hood is draped over the hard-hat.

This provides a significant advantage to the faceshield-balaclava combo as it gives you an air gap being the hood and your head (which improves the protection against heat).

Most hoods now come equipped with an arc flash ventilation system (so it’s not so hot).

Also, as the arc rating increases the newer face shield designs will not continue to get darker and darker (earlier models were impossible to see through at higher arc ratings).

oberon arc flash hood

oberon arc flash hood 40 cal

oberon arc flash ventilation system

af hood ventilation system

pmmi arc flash hood

pmmi arc flash hood

Hearing Protection

Something that may get overlooked is hearing protection.

During normal working conditions, noise may not be an issue, but in an arc flash event, the sound is extremely high and can cause damage.

If there is a chance for exposure to an arc flash then you need to have a pair of ear insert plugs to protect your hearing.

These are safe to wear under your balaclava or arc flash hood, and while some brands may melt when exposed directly to extreme heat they will not melt when underneath the protective equipment (well… if they do melt you have other issues anyway).

Hand Protection

When it comes to protecting the hands of electrical workers you need to shift your focus more toward shock hazards.

Rubber insulated gloves with leather protectors become the primary source of protection from electrical hazards (these protect from both shock and arc flash).

In some cases, you may only require protection from arc flash so you can use arc rated gloves for these scenarios.

rubber insulated glove

rubber insulated glove

electricians glove

leather protector

arc flash glove

bdg arc flash glove

Insulated Rubber Gloves with Leather Protectors

Electrical insulated gloves must meet the requirements of ASTM D120 in order to be used for the protection against shock hazard.

Leather protectors must be worn over the rubber (to protect the integrity of the rubber) and these gloves need to meet ASTM F696.

The leather protectors do offer sufficient protection from the arc flash hazard.

Here is a snippet from the standards:

“If rubber insulating gloves with leather protectors are used, additional leather or arc-rated gloves shall not be required. The combination of rubber insulating gloves with leather protectors satisfies the arc flash protection requirement.”

Primarily the rubber gloves protect you from the shock hazard and there are a number of different “glove classes” to choose from.

Each glove class has a voltage range that it is used for.

Most electricians working on 480 or 600 volts will use a class 0 glove (which is good up to 1000 volts).

For other voltage levels you can refer to this table to determine what glove class is required.

shock hazard glove table

How Do You Inspect Rubber Insulated Gloves?

Insulating equipment shall be inspected for damage before each day’s use using the following method:

  1. Remove leather protector from the rubber insulating glove.
  2. Inspect the leather protector for holes, rips or tears, cracks, and signs of chemical deterioration (note: if any deficiencies are found remove the leather protector from service).
  3. Turn the rubber insulating glove inside out.
  4. Trap air into the glove by spinning the glove from the bead (rolled part at the cuff).
  5. “Pop” the fingers out and visually inspect the fingers, palm, wrist and cuff for holes, rips or tears, cracks, and signs of chemical deterioration (note: if any deficiencies are found remove the rubber insulating glove from service).
  6. Turn the rubber insulating glove right side out and repeat steps 4 and 5.

Testing of your rubber insulated gloves must be done before the first issue and every 6 months thereafter (following the guidelines of ASTM F495).

Foot Protection

There are two things to consider when selecting footwear for electrical workers.

First, will they stand up to an arc flash?

And secondly, do they provide any dielectric protection? Which means… will they help protect you from getting a shock?

While you can never treat you boots as your primary source of protection from shock hazard, a good pair of dielectric boots (or shoes) can provide some additional protection.

(Your rubber gloves are number one)

In the case of an arc flash there is really nothing better than leather boots.

Leather is a great protector from heat energy and most times your feet are far enough away from the source of energy that they are not exposed to the full brunt of the arc flash.

Dielectrically rated leather boots are perfect for an electrical worker.

Now it’s your turn! Please leave a comment

Let me know… 

  • what section has helped you the most; 
  • if you see any ways I could improve this article; or
  • if you have any questions.

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