How to Run an Arc Flash Study and Electrical Hazard Assessment

Arc flashes pose a serious danger to workers in industry. These loud flashes of energy ionize and heat the surrounding air, up to 35,000 degrees Fahrenheit. The CDC reports that five to 10 arc flash explosions occur across the United States every day, and tend to be more common in facilities with denser power structures and higher potential energy.

The resulting heat and pressure wave from an arc flash can injure surrounding employees significantly, causing bruises, burns and even death in some cases.

Generally, an arc flash will occur when a piece of equipment fails due to dust, damage, corrosion or contact with another energized part. Though some of these causes are unavoidable, most of them can be mitigated with examination and implementation of preventative measures. This is why arc flash studies are so crucial to employee safety in arc flash-prone workplaces.

An arc flash will occur when a piece of equipment fails due to dust, damage, corrosion or contact with another energized part

What Is an Arc Flash Study?

An arc flash study, also referred to as an arc flash hazard analysis or an arc flash assessment, is an evaluation of a workplace facility on-site, usually conducted with or by a trained expert in electrical hazard assessment. This study looks at the facility’s electrical system for any potential electrical hazards posing a risk to your employees. These risks include poorly designed electrical pathways and connections, faulty connections and equipment or inappropriate equipment for the application.

A trained expert in arc flash studies and regulations looks for such vulnerabilities, suggests alterations for any fixable problems and then assesses the overall potential for an arc flash to occur.

The study usually takes a day, depending on the size of the facility and the availability of documentation describing the electrical framework of the facility. At the end of the study, the arc flash study expert provides their assessment to the owner, detailing the level of risk and the precautions OSHA requires the owner to take. These precautions include the purchase of protective equipment, employee training and facility equipment upgrades.

Why Does OSHA Require Arc Flash Studies?

The Occupational Safety and Health Act, more commonly called OSHA, came into being on December 29, 1970, as a way to ensure safety and healthy working conditions for men and women across industries throughout the United States.

Part of OSHA — specifically Section 5 — describes the responsibility of employers to remove any recognized hazards likely to cause death or serious physical harm to employees. In June of 1974, these regulations further expanded, requiring the employer to assess the workplace and properly address any potential hazards. Due to their incredible destructive power, OSHA classifies electrical arc flashes as such recognized hazards.

Every year, more than 7,000 burn injuries occur due to arc flashes, 2,000 of which require a hospital stay and 400 of which result in death. Some of those workers hospitalized may miss work for up to a year, and yet others are permanently disabled physically, mentally or psychologically by their injuries and experiences.

Every year more than 7000 injuries occur due to arc flashes

Though arc flashes are common, they are entirely preventable. This places arc flashes under the OSHA umbrella of potential hazards employers must assess and remove when possible.

OSHA and NFPA Requirements for Arc Flash Studies

While OSHA does not detail the requirements for arc flash hazard analyses specifically, the National Fire Protection Association, or NFPA, did so in their 1995 edition of NFPA 70E.

Section 2-3.3.3 details the requirements of flash hazard analyses, and even provides information needed to calculate the flash protection boundary. Specific requirements within NFPA 70E guidelines include the following:

    • Section 110.3 – Standard Electrical Safety: This section requires the employer to implement and document facility-wide electrical safety programs. These programs are protocols designed to direct employee actions to appropriately reflect and account for any electrical hazards present within the facility. Specifically, the section requires the employer to identify and quantify the risks of shock and arc flashes to employees before they begin work, so they can prepare and adjust accordingly.


    • Section 130.5 – Arc Flash Analysis: This section states the importance of an arc flash analysis to determine the arc flash boundary. This assessment is also crucial in determining the incident energy at working distance and the personal protective equipment, or PPE, staff working there should use to protect themselves.


    • Section 130.5 (C) – Labeling: This section requires employers to label all equipment within a work area that will likely be used or maintained while energized. The label details the risk of an arc flash or electrical hazard, the severity of that risk, the arc flash boundary to be observed and the required PPE level of working employees in the area, among other details. Any further content included in the labels may be included at the discretion of the employer.


  • Section 110.1 (A) – Employer Responsibilities: This requirement states that employers hosting contractors or third-party service personnel are responsible for notifying such personnel of any electrical hazards they may encounter while working within the facility. This makes the employer responsible for educating and properly equipping the contractors who work within the facility.

It also means a company using solely contract work must still undergo an arc flash assessment to guarantee the safety of contract employees.

While OSHA requires the mitigation of hazards in the workplace, these NAFP requirements detail the specific responsibilities of employers, the information to be gleaned from an arc flash study and how that information is to be used and acted upon within the workplace.

How Do You Run an Arc Flash Study?

How to Run an Arc Flash Study

In combination, OSHA and NAFP requirements result in a fairly standard arc flash assessment method. Conducted by an expert trained in arc flash analysis studies, OSHA guidelines and NAFP requirements, an arc flash study consists of the following basic steps: 

    1. Collect Documentation: The first step of the process involves gathering all existing drawings of the facility, such as floor plans and riser one-line diagrams. This helps the examiner through the rest of the process. If such documentation does not exist, this means the surveyor must conduct a field survey to create a new one-line. This may lengthen the amount of time needed for the analysis.


    1. Verify Documentation: Before going any further in the arc flash analysis process, the examiner must verify the drawings from the previous step. This verification requires an examination of each site and a comparison with each piece of documentation to determine the accuracy of the information there. If any information is missing or inaccurate, the examiner documents this missing information and develops a more accurate one-line depiction. The examiner will usually combine this step with the first if the examiner needs to conduct a field survey to create a one-line.


    1. Load Information: After completing the field survey and verifying any information collected, the examiner loads the collected information into specialized software, which runs the Short Circuit, Coordination and Arc Flash analyses. 


    1. Run a Short Circuit Study: Once loaded into the software, the analyst reviews the total fault currents and compares them to the duty ratings of the protective devices. If the duty rating of the protective device is greater than the fault current, the device can clear the fault properly. Otherwise, the device will fail and potentially cause an arc flash. Short Circuit studies help determine the energy available for an arc flash.


    1. Run a Coordination Study: After ensuring the viability of each protective device, the analyst examines the coordination of the system as a whole. In proper systems, protective devices will clear any faults without affecting the devices upstream, limiting the effect of the fault on the electrical network. Poorly coordinated systems, on the other hand, result in faults traveling back through the system to trip the building’s main service device, which can bring the whole facility down. Coordination studies also help in evaluating the possibility for an arc flash by helping to determine the amount of time it takes a protection device to clear a fault.


    1. Evaluate Data: These studies and analyses, in addition to an evaluation of the current equipment, provide a more complete idea of the condition of the facility. Based on this preliminary information, analysts can provide recommendations to lower arc flash risks. This data also plays an enormous role in the arc flash evaluation step.


  1. Arc Flash Evaluation: The available arc flash energy, as calculated in the short circuit study, determines the next steps taken by the analyst and facility owner. Using the arc flash energy, the analyst can determine the probable risk to employees, as well as the level of personal protection equipment (PPE) required of workers. This assessment also plays into the labeling and training requirements the employer must meet. In total, this arc flash study provides insights for employers to guarantee the safety of their personnel, helping them implement safe practices and minimize the negative effects in the event an arc flash does occur.

How Can a Company Protect Against Arc Flash?

Steps to Improve Worker Safety

OSHA and NAFP requirements state that employers must take several steps to improve the safety of their employees. This involves both physical protection and general awareness, including the following measures:

    • Worker Training: Over two thirds of all arc flash incidents occur due to employee error, rather than equipment failure or some other cause. Most employees avoid these issues, provided they receive proper training. As part of NAFP 70E regulations, any personnel working within a hazardous work area must be properly trained and informed as to the hazards present within the area. Third-party training specialists versed in OSHA and NAFP regulations tend to be the best providers of such training. In any case, the training must involve basic information, such as the hazards of arc flashes, how to avoid them and the importance of safety precautions like PPE. This simple training session can save lives. 


    • Warning Signs: Both NAFP 70E and the 2002 edition of the National Electrical Code (NEC) require employers to attach labels to any industrial control panels, panel boards and switchboards that may require interaction while energized. These labels detail the potential arc flash hazard involved in using the equipment, in addition to some basic information about the safety level required within the area while energized. This includes the potential energy of an arc flash in the area, the working boundary around equipment and all PPE requirements. More information may be included in this label according to the employers’ preference, but the minimum information required is listed in NAFP 70E.

    • Protective Equipment: OSHA issued regulations regarding safe electrical work practices in 1990, which included a section on the use of personal protection. OSHA 1910.335(a)(1)(i) requires employees working in areas of potential hazard to be equipped with protective equipment appropriate for the parts of the body exposed and the work performed. Specifically, this equipment is referred to as personal protective equipment, or PPE. This PPE is further described in 1910.335(a)(v) as equipment including protective eye or facial wear in environments where there is danger of injury to the eyes or face, and in 1910.335(a)(2)(ii) as protective shields, barriers and insulating materials worn over body parts exposed while working with energized parts. The requirements for this protective clothing were further specified by NFPA 70E in 2000.   Different levels of protection are now required under the regulation, according to the potential risk within each work environment. It also requires the appropriate level of PPE to be detailed in warning labels throughout the facility.

    While these precautions are standard, many employers take further precautions to guarantee the safety of their employees. This includes regular training reviews, stringent protocols and providing more extensive and robust PPE than is required.

    Where Can You Learn More?

    Arc flash assessment is a key part of preventing arc flashes from harming your business and your employees, but these assessments are only half the battle. Employees are the first line of defense against any electrical hazards, so ensuring they know how to prevent hazards is crucial. Not only are training and awareness key parts of any arc flash prevention program, but they’re also required by OSHA and NFPA standards.

    With so much resting on the proper training of your employees, it’s essential to make sure they’re trained by a specialist in the field. If you’re looking to get trained, or to train an employee, on arc flash and electrical hazard safety, Technical Skills Development Services can help.

    Technical Skills Development Services bases our complete training program on the most current OSHA, NFPA 70E and risk management standards, ensuring that your staff receives the most recent information available in the most efficient format. Our teachers come to your facility with a fully realized program, designed to teach your employees how to better handle and analyze electrical equipment and assess it for potential danger.

    Personal protective equipment is a key part of the program, including how to identify and properly use protective equipment. By the end of the program, your employees will know how to effectively prevent an electrical hazard, improving their own safety as well as the safety of their coworkers.

    To learn more about Technical Skills Development Services and how we can help your company with electrical hazard training, contact us today.