Work involving electricity is high-risk, and with every fault, there is a danger of arc flashes. This is why it is important that electrical technicians wear arc flash suits. In this buying guide we outline everything you need to choose the best arc flash suit, and why each step is critically important.
An arc flash is a kind of electrical explosion that results in a rapid and deadly release of heat, light, pressure, and sound energy.
When an arc flash occurs it generates:
- Pressures from 100 to over 1,000 lb/ft
- Sound over 160 dB. (Any sound at or above 85 dB can damage your ear drums)
- Temperatures exceeding 30,000 degree Fahrenheit. That’s over 3 times more than the temperature of the sun’s surface and can vaporize copper wires.
- Flying molten metal and debris at speeds of 700-plus mph
In short, arc flashes can be deadly in the workplace if you are not wearing the proper safety gear.
The Importance of Arc Flash Suits
Since the early 1990s, arc flash suits have evolved thanks to the Occupational Safety and Health Administration (OSHA) and the National Fire Protection Association (NFPA), which regularly update their safety guidelines.
Due to the highly dangerous consequences of arc flashes, rigorous methods are needed to protect electrical workers. Even if these suits do not fully protect you from harm, they can substantially mitigate the effects of electrical arc flashes.
Selection Methods for Arc Flash Suits
Although most people involved in the electrical industry know they need to wear an arc flash suit to be safe, the question remains “how to properly select the kind of suit you need?”
Before you select an arc flash suit, there are some specific preparation steps you need to do, including:
- An arc flash risk assessment
- Calculation of incident energy
- Determining arc flash boundaries
- Appropriately labeling equipment
After doing all of these steps, you can then select the corresponding arc flash suit PPE protection level.
To determine the level of protection required, two methods are commonly used:
- Flash PPE Category Method (Tables Method)
- Incident Energy Analysis Method
Both of the above methods use the same electrical data like the available short-circuit current and fault-clearing type to determine the intensity of the arc flash. You can use whichever method you want, but remember that both of them have a few shortcomings.
Flash PPE Category Method (Tables Method)
A lot of electrical workers prefer this method, since it is pretty straightforward. The Flash PPE Category Method is based on three tables:
- The Task Table
- The Equipment-based Table, and
- The Protective Clothing and PPE table
The Task Table contains a list of various AC and DC tasks which require PPE and the condition of the equipment.
If the task has a flash hazard, you will consult the Equipment-based Table, which is a list of equipment with designated parameters. Here, you will find the arc flash boundary and the appropriate arc flash PPE category.
The last table will list down which PPE or arc flash suit is appropriate for the job.
However, the Category Method has certain flaws. If the equipment is not listed in the Task Table or even a single parameter is exceeded, this table will not offer you any data on what PPE you should use. Also, you will need a thorough knowledge of all the equipment, including the maximum fault clearing time, impedance, and the fault current supplied.
If this information is not available, you should not use the Flash PPE Category Method to choose an arc flash suit.
Incident Energy Analysis Method
The Incident Energy Analysis Method for choosing an arc flash suit is much more complex and time consuming than the previous method. But sometimes it is the only way to make an accurate determination of what arc flash suit you need.
The challenge with this method is that you will have to do a lot of complicated calculations. This means you either have to invest in sophisticated software or hire a professional who can do it for you.
In the end, you will have an arc flash label printed with the incident energy value for all of your equipment.
Once you have the numbers, you only need to pick an arc flash suit that has an arc thermal performance value (ATPV) greater than the incident energy value of that equipment. ATPV is the ability of a fabric to protect the wearer from the hazards of an arc flash.
The arc flash PPE chart below gives the NFPA 703® PPE required based on calculations.
|Category||Minimum ATPV Rating (Cal/cm2)||Protective Clothing and PPE Table|
|1||4||Long-sleeved shirts and pants or overalls; flash suit hood or faceshield; hearing protection; hard hat; leather gloves and shoes; safety googles|
|2||8||Long-sleeved shirts and pants or overalls; flash suit hood or faceshield; hearing protection; hard hat; leather gloves and shoes; safety googles|
|3||25||Long-sleeved shirts and pants or overalls; flash suit hood or faceshield; hearing protection; 25 cal flash suit jacket, pants, and hoods; hard hat; leather gloves and shoes; safety googles|
|4||40||Long-sleeved shirts and pants or overalls; flash suit hood or faceshield; hearing protection; 40 cal flash suit jacket, pants, and hoods; hard hat; leather gloves and shoes; safety googles|
What to Inspect on Your Arc Flash Suit
To ensure your arc flash PPE provides you the most protection, you should inspect it thoroughly each time you put it on.
Faceshield and Hard Hat
Faceshield: ASTM F2178 compatible
Hard hat: CAN/CSA-Z94.1
Make sure your hard hat or faceshield is not cracked, warped, or has broken adapters. Make sure you can clearly see through the visor of your faceshield to ensure it is not very scratched as this doesn’t just reduce visibility, it will also weaken the protection.
Also make sure you wear protective goggles under your faceshield.
Balaclava or Arc Flash Hood
Arc flash hood: ASTM F1506 compatible
There are many cases of people who suffer from 2nd or 3rd degree burns to the head or face due to arc flashes. Make sure your balaclava is ATPV-rated and does not have any rips or holes in it. It should also be rated with an ATPV greater than the incident energy level.
Make sure you also wear ear canal inserts beneath your balaclava as well to protect your ear drums from loud sounds.
Clothing: ASTM F1506
If 70 percent of your body is burned, your chances of survival are greatly reduced. An arc-rated shirt and pants covering over 70 percent of your body is extremely vital.
Make sure your shirt, trousers, jacket, and overalls do not have any cuts, holes, or rips. Also look at the elbow and knee areas as they can get thin and worn down over time. If that is the case, you need to get a new set that is rated for the appropriate hazard level.
Never unbutton your shirt or roll up your sleeves as that will leave your body exposed.
Arc-rated gloves work very well to prevent injury from arc flashes. The best types of gloves are rubber insulating gloves as they not just protect you from arc flashes but electrical shocks as well.
These are rated according to the voltage. The ASTM classes for voltage-rated gloves are:
- Class 00 glove for <= 500V
- Class 0 glove for <= 1000V
- Class 1 glove for <= 7.5KV
- Class 2 glove for <= 17KV
- Class 3 glove for <= 26.5KV
- Class 4 glove for <= 36KV
Once you have decided on the appropriate rubber glove, you should also invest in a good leather protector that will protect your rubber glove from damage.
Shoes: ATSM F2413, CAN/CSA Z 195, or ASTM F1117 compatible
Normal shoes do not have shock protection abilities. Additionally, you don’t want to wear anything that melts in the face of intense heat.
ATSM F2413 and CAN/CSA Z 195 ratings are only for the soles of the shoes.
The ASTM F1117 rating is for dielectric shoes and can provide protection from electrical shocks as well. These type of shoes are rigorously tested by the manufacturer from the tip of the toes down to the heel.
Companies should issue shoes to their workers that do not ignite over 40 cal/cm2 arcs.
Benefits of Wearing the Right Arc Flash Suit
Arc flash suits offer a lot of protection to the wearer. This includes protection from:
An arc flash can generate a massive amount of heat — this should not be confused with a fireball, we will discuss that later.
Your arc flash clothing should be able to absorb the worst of the heat energy. This can be in excess of 30,000 degrees Fahrenheit. To ensure this, the material of your suit should have an ATPV that can withstand an arc flash exposure substantially greater than you think.
To be on the safe side, you should look for an APTV of at least 8, even if the work carries small risks.
An arc flash produces blinding light levels. Workers who have been caught off-guard have experienced short-term or long-lasting blindness (if not permanent). A flash face shield is used to protect your eyes from the highly intense and harmful light and heat from the flash.
That’s why face shields are tinted. Thanks to advanced technology, you can now choose one in grey, orange, or green tint as well as other shades.
Arc-rated suits do not just absorb the heat from the flash; they are also made of fire-resistant material in case an explosion causes a fireball. Fire protection includes not just the shirt and trousers, but also your protective face and head gear. After all, you don’t want your hair to catch on fire.
Sound at or above 85 decibels can render you deaf. An arc flash can result in sound as loud as 160 decibels. Ear canal inserts will protect you from excessively loud sounds. They easily fit under your balaclava or arc flash hood.
When an arc flash occurs, it has the potential to melt copper wire. As a result, you may be bombarded with shrapnel of molten copper. That’s why you wear your face shield.
However, in extreme circumstances, even your face shield can crack and debris can fly into your eyes. For this reason, it is important that you add another layer of protection in the form of high-impact goggles or safety glasses. These extra eyewear are designed to handle flying debris.
Arc Flash Suits – Frequently Asked Questions
If you have further questions about arc flash suits and how to choose the right one, read through these FAQ posts below. We probably have an answer for you.
- What is an arc flash suit?
- How are arc flash suits rated for protection?
- When are arc flash suits required?
- How does an arc flash suit work?
- How to use an arc flash suit?
- How to choose an arc flash suit?
- How to clean an arc flash suit?
- How to inspect an arc flash suit?
- How to prevent arc flashes?
Bottom Line – Choose Your Arc Flash Suit Wisely!
According to Industrial Safety and Hygiene News, there are about 30,000 arc flashes incidents every year, which result in 7,000 burns and 400 fatalities. These statistics are shocking, even more so because 80 percent of deaths occur due to burns rather than electric shocks.
Remember that just wearing any arc-rated suit cannot guarantee your safety — it needs to be an arc flash suit that has an ATPV greater than the incident energy value. It is extremely vital that electrical workers wear the appropriate arc flash suits to protect themselves from this very real hazard.
Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree in Economics from U.C. Davis, is an active outdoorsman and spent years ensuring the safety of special needs children. Nick researches and tests workplace, industrial and safety products and provides advice on their safe use.