Today you’re going to learn everything you need to know about Arc Flash PPE.
In fact, these are the exact topics that I teach during our qualified electrical worker course.
The best part is that you will be able to apply all these tips and strategies right away.
So, if you want to learn:
How to select your arc flash PPE;
How to inspect your arc flash PPE; and
How to maintain your arc flash PPE.
then you are in the right place!
Let’s get started.
#1: THE BASICS
There’s more than one arc flash hazard
Arc flash is scary because you have to deal with more than one hazard at the same time.
Just take a quick look at this image… you can see that there are a lot of things you need to consider.
Dealing with the heat.
The heat will impact your entire body and everything you need to wear so let’s take a look a this first.
You need to make sure you’ve got yourself covered with something that will protect you from the heat energy… don’t get this confused with the fire ball, that will come later.
You need something that can absorb the heat and protect your skin from the worst sun burn you would have ever gotten… this “sunburn” would be to the tune of 20,000 degrees Celsius.
The material used for heat protection has to have an Arc Thermal Performance Value (ATPV) or a Breakopen Threshold Energy (EBT) that is suitable for the arc flash exposure… more on this later.
Most times I’m looking for an ATPV of at least 8.
Seems easy...what's the trick?
The trick is that you have to know what the potential incident energy of the equipment you are working on is.
One way to find out is by performing arc flash hazard calculations… this is by far the best way to understand just how much heat energy you are up against.
The heat energy is measured in calories per centimeter squared or cal/cm^2.
Essentially if you are wearing something with an ATPV rating that is a higher number than the cal/cm^2 then you will be fine.
#2: HEAD PROTECTION
If there is one part of my body I want to protect from severe burns, which would alter the way I look for the rest of my life, it’s my face.
Too many arc flash incidents lead to people having 2nd and 3rd degree burns to their face, ears and head.
Not to mention, they are at risk of going blind from the extremely bright light generated from the arc flash as well as deaf from the loud sound produced which usually hovers around the 160 dB mark (that’s like standing next to fighter jet on the runway… with no hearing protection).
So firsts let’s make sure we understand all the hazards our face, neck, eyes, ears and head have to deal with.
We already mentioned the heat
Like I said earlier… make sure all your head protection (faceshield, balaclava, or arc flash hood) have an ATPV that is suitable for the arc flash hazard.
You’ve got a couple options to choose from.
Your two choices to protect from the heat will be either an arc flash face shield with balaclava or an arc flash hood (which really does it all).
Arc Rated Faceshield & Balaclava
Arc Flash Hood
Dealing with the light.
During the arc flash there is an insane amount of light produced and if you ever talk to an arc flash survivor they will almost always tell you they were temporarily blinded (if not permanently)… which is never a good thing when you are on fire.
To make sure you have adequate protection for your eyes you’ll need to wear an arc flash faceshield.
The technology in the faceshield is designed to protect your eyes from the intense and harmful light emitted from the arc flash (not to mention the heat energy).
This is why the faceshields are tinted.. what’s really cool is that you no longer have to struggle with dark orange and green tinted faceshields as the technology has gotten that much better.
Find one with a grey tint that looks similar to the one in this picture.
What about the fireball?
Arc rated protective equipment not only needs to absorb the heat energy from the arc flash but it also needs to have the Flame-Resistant (FR) properties similar to what you would wear in case of flash fire.
Basically, if you are in an arc flash, you don’t want your head (or anything you are wearing on your head) to catch on fire.
If the arc flash faceshield & balaclava or arc flash hood have an ATPV rating then it will also have the flame-resistant properties you need.
What?! I can’t hear you…
The sound produced during an arc flash is very loud.
In order to combat that you’ll need to wear hearing protection.
There are different types of hearing protection on the market but ear canal inserts are really the most practical.
You need to wear these underneath your balaclava or arc flash hood so having the big earmuffs on is not going to work.
But what if they melt?
Great question… and here is the answer provided by this fantastic image from e-hazard.
Flying pieces of molten copper
The last thing we need to make sure we’ve covered is all these flying pieces of molten copper.
When an arc flash happens it’s like a grenade going off.
Just take a look at this video from Westex… pause it right at the 24 second mark to see what I mean.
Now… you would think that your arc flash faceshield would do the trick but right now there is no way for the manufacturers to prove it… there is no standard they can test to (as far as I know).
So you still need to wear your standard safety glasses along with the arc flash faceshield and underneath the arc flash hood.
Safety glasses are designed to handle ballistics… arc flash face shields are not.
#3: HAND PROTECTION
Hand protection for arc flash is actually quite simple because you can use your rubber insulated gloves that you would use for shock hazard.
This quite fortunate because most times you are exposed to an arc flash hazard you are also exposed to a shock hazard.
What about arc flash gloves?
Arc flash gloves will work fine… but as I stated above they will only work in situations where there is only an arc flash hazard.
One example would be racking a breaker on a dead-front motor control center.
Little to no risk of getting a shock… extreme arc flash risk.
If I was going to spend money on something it would be my rubber insulated gloves because they are going to get much more use and cover both hazards… but the arc flash gloves do have their place.
How do I choose a rubber glove?
Even when it comes to protection from arc flash you still need to choose your gloves based on the shock hazard.
This makes sense for a couple of reasons.
There are way more shock incidents than arc flash incidents; and
If you have the wrong rubber insulated gloves for the voltage level you are working on you won’t really need to worry about the arc flash… because you will likely have already gotten shocked.
ASTM Glove Chart
Probably the most well known and used chart to determine the correct rubber insulated glove is this ASTM chart.
Basically, you figure out what voltage you are working on and then choose the gloves that are rated higher than what you need.
So 600 volts AC would require Class 0 Color Red.
Don’t forget the leather protectors!
Once you’ve got the appropriate rubber insulated glove selected you need to make sure you have selected the a properly sized leather protector.
The nice thing about leather is that it not only protects the rubber insulation from being damaged but it offers additional arc flash protection as leather is a great protector from heat energy.
The combo will look like this.
#4: BODY PROTECTION
This is what everybody came for… right?
And by rights… it should be.
When you are strictly talking survival (versus still looking good after a bad burn)… if you have burns to more than 70% of your body then your chances of living are greatly reduced.
By wearing an arc rated (AR) shirt and pants alone you have covered more than 70% of your body… so we can’t ignore that fact.
Clothing is super important.
But don’t get me wrong… you need to cover everything (head, face, neck, hands, feet)!
What are my options?
Today it seems the options are endless… shirts, pants, high-visibility, waterproof… you name it.
There are a ton of great brands on the market making all kinds of unique and interesting arc flash clothing.
Just make sure you check a couple of things before you make your choice…
That the clothing meets ASTMF1506 - 18;
That it covers your entire body (don’t roll up sleeves or unbutton the shirt);
That it looks good… just kidding;
That it’s comfortable… you don’t want to give yourself any excuse not to wear it.
What about cotton? Electricians always wore cotton…
Ahh… watch this…
That’s a resounding NO for those of you who didn’t watch.
What about layering?
So you want to wear you arc flash jacket over your arc flash coveralls?
There is never a case when doing this will reduce your protection.
But I thought you were not supposed to do that?… you say.
Well, the thing is in order to know exactly what the ATPV of the layered system would be you technically need to test it… so rumor was that you couldn’t just simply add the two ATPV together to come up with a new rating.
But here is a little secret.
It will always be higher… every test that I’ve ever seen done came back higher than the two added together. Probably due to the air gap between the clothing.
Does some heat still get through?
Technically a shirt rated 8 ATPV when exposed to an arc flash of 8 cal/cm^2 has potential to allow through enough heat energy to cause the onset of a second degree burn… go figure?
But here is a couple things that will make you feel better about this.
It will only happen 50% of the time;
At any one time there is less than 30% of your body actually in contact with your clothing… so most of it is protected by air;
Arc flash calculations are slightly conservative (although this might be changing)… so you should be fine.
The easy solution…
Always wear a bit more than what’s on the label.
#5: FOOT PROTECTION
Foot protection is pretty straightforward for arc flash.
Wear leather boots… not ones that will melt.
That’s about all you need to know.
#6: SELECTION METHODS
We’ve already touched on this a bit here… but for the most part you have two ways to determine what arc flash PPE you need for the job.
The incident energy method; and
The category method.
Each method has there flaws… but we will go over them here and you can decide how you want to proceed.
The incident energy method
From an ease-of-use and simplicity standpoint for selecting your clothing this is the way to go.
The problem… is figuring out what the numbers are in the first place.
Once you get it figured out though it’s fantastically easy.
Here is what you end up with... an arc flash label on all of your equipment.
OK Great… but how do i choose my PPE?
Well.. remember when we talked about arc thermal performance value (ATPV)?
All you need to do is make sure you are covered head to toe in an ATPV that is greater than the incident energy value printed on the label.
In this case it’s 0.4 cal/cm^2… which is ridiculously low… so it should be easy to protect against that!
The category method
I’ll come right our and say it.
I don’t like this method… reason being is this little tidbit of information that often get’s overlooked.
You need to be able to determine the available fault current and maximum fault clearing time in order to properly use this method.
Which means in order to do it properly you will be half way (or maybe more than half way) to a full blown incident energy study.
Most people that try this method end up like this…
#7: INSPECTION METHODS
Here are the most important things to check for each item of PPE you need.
Hard hat & faceshield
Look for any damage to the shield, cracks, breaks, or or broken adapters.
Make sure it fits properly and you can see through the visor (not excessively scratched).
Hard hat meets CAN/CSA-Z94.1
Faceshield meets ASTM F2178
Check for any cuts or holes.
Make sure it’s rated for the hazard level (ATPV > cal/cm^2).
Meets ASTM F1506
Check for any cuts or holes.
Also look at the knees and elbows to see if it’s getting thin… if so, then get a new set!
Make sure it’s rated for the hazard level (ATPV > cal/cm^2).
Meets ASTM F1506
Rubber insulated gloves with leather protectors
From an arc flash standpoint just make sure they are free of debris and do not have any cuts, holes or other signs of damage.
From a shock hazard perspective watch this video.
Cleaning arc flash clothing has been one of the most heavily debated primarily because the original arc flash clothing was “treated”.
Now you can get what’s called inherent FR…
Here’s a quote from a great article I found on the differences between inherent FR and treated FR.
Inherent FR fabrics are made of fibers in which the FR properties are naturally part of the polymer backbone and can never be worn away or washed out. The actual structure of the fiber itself is non-flammable; therefore, the flame trait is permanent.
The first thing you want to do is check what type of clothing you have.
If it’s treated then you are going to need to take special care of how it’s washed.
Might sound like a cop-out but you’ll need to follow the specifications from your clothing manufacturer if you want to get it right.
As for inherent FR, in my opinion, it’s not as critical but you’ll still want to stay away from cleaning supplies which could damage the arc rating capabilities of the clothing.
You can also pick up a copy of ASTM F1449 (Standard Guide for Industrial Laundering of Flame, Thermal, and Arc Resistant Clothing) for more information.
#9: ARC FLASH PPE CHART
For your copy of the arc flash PPE chart you can head over to this article and grab one.
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.