Arc Flash Standards

Frequently Asked Questions

Arc Flash Standards

An Arc Flash is a violent electrical explosion or discharge. It is caused by an Arc fault and produces extreme heat with up to 35,000 degrees Fahrenheit. This event causes grave danger to anyone standing close to such an Arc Flash. Personal Protective Equipment (PPE) effectively shields the worker from the extreme radiation and heat of the arc flash. It is estimated there is an average 30,000 Arc Flash incidents every year. These incidents results in average annual totals of 7000 burn injuries, 2000 hospitalizations, and 400 fatalities.

What are common causes?

  • Unintentional contact between an energized conductor with another grounded element.
  • Equipment failure or using incorrectly specified instruments.
  • Dropping of un-insulated tools or metal parts that make contact.
  • Live work on damaged equipment like cables or test instruments.
  • Loose connection and exposed live parts.
  • Lack of awareness and training.

How do I select the appropriate Arc Flash PPE according to NFPA 70E or CSA Z462?

According to NFPA 70E Standards for Electrical Safety in the Workplace there are two potential methods for determining arc flash PPE.

  1. The incident energy analysis method in accordance with table 130.5(G)
  2. The arc flash PPE category method in accordance with table 130.7(C)(15)

Depending on which method is used the tables in NFPA 70E can help you identify what arc flash PPE is required.  Table 130.7(C)(15) has been recreated by Oberon and can be used to assist you in identifying what arc flash PPE you should select when using the arc flash PPE category method.

If you are using the incident energy method to select your arc flash PPE the recreated NFPA 70E Table 130.5(G) listed below can be used as a reference.  Please reference NFPA 70E Standards for Electrical Safety in the Workplace directly for any specific questions on the guidelines listed in this FAQ.

Incident energy exposures equal to 1.2 cal/cm2 up to 12 cal/cm2

  • Arc-rated clothing with an arc rating equal to or greater than the estimated incident energy level.
  • Long-sleeve shirt and pants or coverall or arc flash suit
  • Arc-rated face shield and arc-rated balaclava or arc flash suit
  • Arc-rated outerwear (e.g. jacket, parka, rainwear, hard hat liner)
  • Heavy-duty leather gloves, arc-rated gloves, or rubber insulating gloves with leather protectors
  • Hard hat
  • Safety Glasses or safety goggles
  • Hearing protection
  • Leather footwear

Incident energy exposures greater than 12 cal/cm2

  • Arc-rated clothing with an arc rating equal to or greater than the estimated incident energy level.
  • Long-sleeve shirt and pants or coverall or arc flash suit
  • Arc-rated arc flash suit hood
  • Arc-rated outerwear (e.g. jacket, parka, rainwear, hard hat liner)
  • Arc-rated gloves or rubber insulating gloves and leather protectors
  • Hard hat
  • Safety Glasses or safety goggles
  • Hearing protection
  • Leather footwear

If NFPA 70E and CSA Z462 require a hood be worn when the incident energy level is above 12 cal/cm2 why does Oberon Company sell a 25 cal/cm2 hard cap and shield combo with a balaclava?


There are many standards involved when dealing with electrical safety in the workplace.  NFPA 70E and CSA Z462 both help to lay the groundwork for companies to create electrical safety programs that protect the welfare and safety of their workers.  While these standards are a great reference for companies to review, they can not cover all situations or environments.  In Article 90 of the NFPA 70E standards certain industries are excluded and are listed below.

  1. Installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.
  2. Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communications purposes.
  3. Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations.
  4. Installations under the exclusive control of an electric utility.
These exclusions create some confusion on what to reference should electrical work need to be on installations of this nature.  The National Electric Safety Code or NESC attempts to solve this issue by providing ground rules for safeguarding of persons during the installation, operation, or maintenance of power, telephone, cable TV,, and railroad signal systems.  This is of particular importance when discussing Arc Flash PPE.  Since the installations listed above are not covered by NFPA 70E standards, they will refer to NESC guidelines when selecting Arc Flash PPE.
In Part 4, Section I of the NESC guidelines it states the following.
  • I. Clothing
    1. Employees shall wear clothing suitable for the assigned task and the work environment.
    2. When employees will be exposed to an electric arc, clothing or clothing system shall be worn in accordance with Rule 410A3.
    3. When working in the vicinity of energized lines or equipment, employee should avoid wearing exposed metal articles.
If we then look at Rule 410A3 it states that if an assessment determines a potential employee exposure greater then 2cal/cm2 exists that the installation should, “Require employees to cover the entire body with an arc rated clothing and equipment having an effective arc rating not less than the anticipated level of arc energy.”   This requirement does not stipulate the specific type of Arc Flash PPE to be used, just that it is appropriately rated and covers the entire body.  As a result, workers such as Powerline Technician may have a need for a 20+ cal/cm2 ensemble that allows for maximum flexibility while working.  Oberon Company created an arc flash kit for just such occasions.  It is consists of a coverall, hard cap and shield, balaclava, and kitbag.  All of the components of this kit are rated to protect the worker up to exposure levels of 25 cal/cm2.  We call this kit the TCG25-CKE-NB Series.

What are the OSHA requirements for a glove inspection?

OSHA requires that “protective equipment be maintained in a safe, reliable condition.” Gloves should be inspected for tears, holes, ozone cuts and other defects before each use. For more information, refer to the ASTM F1236-16 standard guide for the visual inspection of electrical protective rubber products.  Also, gloves should be inspected for any swelling, which is generally caused by chemical contamination (specifically petroleum products). Even the slightest swelling can be an issue.  If the electrical gloves show any signs of the defects discussed above upon inspection, they should be taken out of service for cleaning and retesting (even if it hasn’t met the six month “in-service” rule or the 12-month shelf life rule discussed in the date stamp section of this article) per ASTM D120-14a requirements.

Why do rubber electrical gloves have a date stamp on them?

According to the Occupational Safety and Health Administration (OSHA) in 29 Code of Federal Regulations (CFR) 1910.137(c)(2)(viii), all electrical gloves must be tested periodically and prior to being placed into service. All glove manufacturers incorporate some form of production code or date coding to indicate the date of initial testing. Rubber insulating gloves must be tested before first issue and every six months thereafter or upon indication that the insulating value is suspect; after repair; and after use without protectors. Also, if the insulating glove has been electrically tested but not issued for service, the insulating glove may not be placed into service unless it has been electrically tested within the previous 12 months. For additional information on in-service care of electrical gloves reference ASTM F496-20. 

These testing requirements can sometimes be a little confusing to interpret. Here’s an example: You’re considering using your electrical gloves for the first time on January 1, 2017, and notice the date stamp is November 1, 2016. Would you need to get the gloves retested before use? No, because you will be putting the gloves into service within the allowable 12 month window.


How do I select the right arc flash PPE based on voltage?

Selecting appropriate arc flash PPE knowing only the voltage is impossible.  You must have the fault clearing time and the available fault current as well as the voltage.  If the equipment is in normal operating condition, you may be able to utilize the NFPA 70E 130.7 tables to select appropriate arc rated PPE.

I have been told that most electrical work I do falls within Arc Flash PPE Category 2, is that accurate?

No, it is impossible to know what protection is necessary without first completing an arc flash risk assessment. While it is true that the majority of energized work does fall within Arc Flash PPE Category 2 or have thermal incident exposure values below 8 cal/cm2, you can’t assume anything. You must use either the Incident Energy Analysis Method or Arc Flash PPE Category Method as part of your arc flash risk assessment to determine what protection is necessary.

If we don’t do any high voltage work, what type of PPE do we need?

Voltage does not determine the arc flash hazard. Knowing the voltage is only one piece of determining Arc Flash PPE. The electrode orientation, available fault current (amps), the working distance between the worker and the equipment, the clearing time of the circuit protection device, the spacing between conductors or from a conductor to ground, the number of phases, whether the conductors are in an enclosure, and the equipment configuration must all be considered when determining the potential severity of an arc flash hazard.

NFPA 70E provides two methods for the selection of arc flash PPE as part of an overarching requirement to complete an arc flash risk assessment. The two selection methods are:

  • Incident energy analysis method. Often referred to as an “arc flash study”, requires engineering calculations to determine the potential thermal incident energy in the event of an arc flash. Arc flash PPE is then selected so the arc rating (protection) matches or exceeds the calculated incident energy. Both the thermal incident energy and protective arc ratings are calculated as calories per square centimeter (cal/cm2).
  • Arc flash PPE category method. Otherwise known as the “table method”, involves a simplified approach using the tables from within the Standard to determine a category number from 1-4 and corresponding arc flash PPE minimum requirements. The table method requires validation of the parameters used in the creation of the categories, otherwise the user is forced into using the incident energy analysis method. Refer to Oberon’s catalog on page #5 for arc flash PPE category product information.

Either, but not both, arc flash PPE selection methods can be used on the same piece of equipment. The engineering calculations used in the incident energy analysis method cannot be used to specify an arc flash PPE category. Keep both methods separate and document your decision making processes within your company’s Electrical Safety Program.

The bottom line is that you can’t rely on voltage alone to figure out what arc flash PPE you need. NFPA 70E requires the employer to complete an arc flash risk assessment. If additional protective measures are required, arc flash PPE can be applied as a control to mitigate the risk of an arc flash. Refer to the latest edition of the NFPA 70E Standard to learn more about the requirements for an arc flash risk assessment.

What is ASTM F2178 – Standard for Arc Rated Eye or Face Protective Products?

ASTM (American Society of Testing and Materials) developed this F2178 standard in order to evaluate the arc protective value of face and head protective devices. Prior to the issue of this standard in August 2002, there was no standard that addressed the evaluation of a finished product, just the component fabric of a garment (ASTM F1506).

Every manufacturer of hoods and faceshields should conduct testing on the hoods and faceshields they sell. Oberon has conducted complete F2178, testing on its TCG™ Series, LAN™ Series and CAT™ Series, and ARC140™ Series hoods, as well as on its arc flash faceshields.

The importance of this standard is neither the product manufacturer nor the enduser know how the product will perform unless it is actually tested under arc conditions. While the fabric used to construct the hood may be arc-rated and flame resistant, other components may not be.

We have seen competitors’ arc flash hoods burst into flames when tested and require a fire extinguisher to put out the flames even though it was labeled “Meets ASTM F1506.” Furthermore, this testing evaluates the design of the product to ensure it works as well in the real world as it seems to in the theoretical world.

An arc flash personal protective equipment manufacturer is required to provide a report on the F2178 evaluation of its product, if asked by a consumer.

Current standards for arc flash thermal protective products are manufactured to comply with a variety of ASTM and ANSI standards. The standards dictate how products should be tested.  They do not require any retesting of the garments after manufacturing as the current tests are destructive in nature and would render the PPE unusable after testing.

It is advisable for the user, before and after every use of an arc flash PPE product, whether it be a coat, pants, hood face shield, or accessory, to inspect the product for damages, including rips and tears, as well as any soiling, especially oil or other combustible material, which could adversely impact the arc thermal protective characteristics of the product. If any damage or soiling occurs, the user should not use that product until cleaning or repairs are made in accordance with the instructions of the manufacturer.

Additionally, it is important to not reuse an arc flash protective product after an exposure to an arc incident.
Your arc flash protection, when properly selected and worn, can save your life, protecting you against the thermal energy of an arc incident, preventing the onset of a second-degree burn. Proper care and respect should be taken in the handling and care of your protection.

What version of NFPA 70E is OSHA using as the standard for citation determination?

NFPA 70E has not been adopted by OSHA as a regulation. NFPA 70E is generally referenced, in the event of an incident, under the General Duty Clause since it is an industry recognized best practice standard.

Can I use your electrical arc flash products in the food industry?

Within the food industry, consideration must be provided for Hazard Analysis and Critical Control Points, or HACCP. This is a systematic preventive approach to food safety from biological, chemical, and physical hazards in production processes that can cause the finished product to be unsafe and designs measures to reduce these risks to a safe level.

Arc flash PPE can contain materials that would be unsafe within the food production processes that can cause the finished product to be unsafe. An example would be the use of non-metal components such as buttons and ear canal inserts. Metal detectors are often used as part of the employer’s preventative approach to food safety, but would not catch these hazardous arc flash PPE components.

Oberon can customize any arc flash garment to use only hook & loop closures, i.e. Velcro. Contact Oberon for assistance with your arc flash PPE selection when using the products within a food processing environment.

Our equipment labels are 3 years old. Do we need to re-print our labels with the new Standard requirements?

The process of creating equipment labels is often a result of completing an arc flash incident energy analysis. The NFPA 70E Standard states that an incident energy analysis shall be updated when changes occur in your electrical distribution system that could affect the data on your labels. So the answer is if nothing has changed in your electrical distribution system, then the labels are still valid.

You will however need to address your equipment labels when the incident energy analysis needs be reviewed for accuracy at intervals not to exceed 5 years.

An equipment label exception identified by the Standard is that unless changes in the electrical distribution system(s) render the label inaccurate, labels applied prior to the effective date of the latest edition of the Standard shall be acceptable if they complied with the requirements for equipment labeling in the Standard in effect at the time the labels were applied.

Does the Economy Series face shields from Oberon meet any standard?

The Economy series face shield complies with ANSI Z87.1 for protection. This shield offers a truly low price for everyday shop, industrial and laboratory eye and face protection. Comfortable headgear allows for extended use without tight pinch points, unlike other low cost shields. Headgear is available in ratchet adjustable and snap fit adjustable styles.

What standards does Oberon’s hard cap meet?

Our Hard Hats meet either the ANSI Z89.1 or CSA Z94.1 Standard (Canadian Caps only) along with meeting the Edison Electrical Institute:

  • Class E Tested to 20,000 volts
  • Class G Tested to 2,200 volts
  • Class C No electrical protection

OSHA states that the wearer should always inspect their PPE before donning, how?

Before donning your protective eyewear, make sure it is clean and there are no smudges, dirt or oil obscuring your vision. Check the frame making sure it is clean and in working order, don’t tape or glue your spectacles the structural integrity of the glasses is important to your safety.