As electricians, we understand that there is an inherent risk associated with performing our daily job duties. Aside from the many other non-electrical-related risk exposures that we face on the job site, such as the potential for falls and work being performed in confined spaces, there are two distinct electrical-related hazards that electricians face: electric shock and arc flash incidents. While many — dare I say most — electricians have experienced an electric shock on some level, few have experienced an arc flash either directly themselves or indirectly through a coworker. In fairness, many may not even know what an arc flash is, let alone how to limit their exposure to one.
What is an arc flash?
NFPA 70E®, Standard for Electrical Safety in the Workplace®, defines an arc flash hazard as a source of possible injury or damage to health associated with the release of energy caused by an electric arc. An arc flash hazard exists if a person is (or might be) exposed to a significant thermal hazard. A significant thermal hazard is an incident (thermal) energy of 1.2 calories per square centimeter (Cal/cm2) or more.
According to the Stoll curve burn injury model, the onset of a second-degree burn on unprotected skin is likely to occur at an exposure of 1.2 Cal/cm2 for one second (see the Figure). Based on this criterion, NFPA 70E establishes the arc flash boundary at the point at which the incident energy level equals 1.2 Cal/cm2 — essentially the level at which a person could potentially receive second-degree burns, should an arc flash occur.
Expect the unexpected
Even when every precaution known to mankind is taken, there is still potential for an arc flash to occur. Sometimes, the equipment just fails. It could be a manufacturing defect, or maybe a loose bolt falls onto a live bus at the most inopportune time. Humans are fallible, and there is always a chance a tool could be dropped while working, triggering an arc flash event. So, knowing the risk involved, it only makes sense for electricians to determine how best to mitigate potential hazards.
Can you imagine an astronaut exploring the moon without wearing a spacesuit? What about a knight going into battle without armor? Dating back to medieval times, humans have understood the need to alleviate the risk involved with the tasks that they are engaged in, so it should not fall amiss to a modern-day electrician. The risks we face while performing our jobs are very real — every bit as risky as an astronaut or a knight — and should be treated as such. The decisions we make can mean the difference between us living to see another day or never going home.
Who is responsible for arc flash safety?
It is important to note that the onus of managing electrical safety risk is not solely the responsibility of the employee but also falls upon the employer. NFPA 70E established requirements for both the employer and the employee. The overarching requirement for employers is that they implement and document an overall electrical safety program (ESP) that directs activity appropriate to the risk associated with electrical hazards, such as electric shock and arc flash exposure, that their employees face on the job and train their employees in the established procedures.
While there is much that goes into creating an ESP, it is required to be developed to provide the required self-discipline for all employees who must perform work that may involve electrical hazards. This, in turn, shifts the onus back to the employee, who is required by NFPA 70E to comply with the safety-related work practices and procedures as established by the employer.
Recent arc flash hazard guidance updates from OSHA
As an employer and employee in the United States, there is another level of accountability for electrical safety, and that is to meet regulations as enforced by the Occupational Safety and Health Administration (OSHA). In the fall of 2024, OSHA took a significant step by directly acknowledging and addressing arc flash hazards that employees face by releasing guidance on how to better protect employees from these risks. This information, coming directly from OSHA, casts a spotlight on arc flash hazards for employers and employees to understand how to identify risk and be better prepared to combat those challenges through the standardized use of appropriate personal protective equipment (PPE).
At present, this information is being shared as guidance and is not considered to be a standard or regulation. The introductory paragraph to the published report states:
This guidance is not a standard or regulation, and it creates no new legal obligations. It contains recommendations as well as descriptions of mandatory safety and health standards. The recommendations are advisory in nature, informational in content, and are intended to assist employers in providing a safe and healthful workplace. The Occupational Safety and Health Act requires employers to comply with safety and health standards and regulations promulgated by OSHA or by a state with an OSHA-approved state plan. In addition, the Act’s General Duty Clause, Section 5(a)(1), requires employers to provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm.
For those familiar with the Occupational Safety and Health (OSH) Act of 1970 that established OSHA and the regulations that are enforced, the General Duty Clause referenced at the end of the introductory paragraph shown above should pique your interest in considering why this may be referenced here. Let that resonate in your mind for a moment as we explore what information the OSHA arc flash guidance provides, and we will circle back to this thought a little later in the article.
Debunking arc flash misconceptions
Initially, the guidance delves into addressing a couple of fallacies developed in the electrical industry over the years around arc flash hazards. The first of these myths is that workers mistakenly assume that they do not need arc flash PPE because, in their viewpoint, they are not performing energized work. Simply deenergizing equipment — even when the appropriate lockout/tagout (LOTO) process is utilized — does not determine that they are therefore performing deenergized work on the associated equipment.
An electrically safe work condition (ESWC), as established based on NFPA 70E, is required to verify that equipment is completely deenergized and able to be safely serviced. While LOTO is a significant step in the seven-step (eight steps if temporary protective grounding is required) ESWC process, it is not the only step. The seventh step requires that the employee test for the absence of voltage at each point of work. This step would require the employee to assume all equipment is still energized until proven otherwise, and therefore require the employee to wear appropriately rated arc flash-rated PPE to be utilized while testing for the absence of voltage.
The second electrical industry myth addressed in the OSHA arc flash guidance is around the topic of justified energized work. Electricians can be put in many precarious positions that put their safety at risk simply because whoever they are performing the work for does not want to be inconvenienced by having them do the work during off-hours or having a portion of their production line shut down. Let me be clear that inconvenience is never a justification for performing energized work. NFPA 70E requires an ESWC to be established anytime there are energized conductors or parts operating at 50V or greater, and the employee is working within the limited approach boundary or interacting with equipment without exposed conductors or parts, but an increased likelihood of injury from an exposure to an arc flash hazard exists. The two main exceptions in NFPA 70E to establishing an ESWC and being able to perform work energized are when:
- The employer can demonstrate that the task is infeasible in a de-energized state due to equipment design or operational limitations. An example where this may be infeasible is in the instance of troubleshooting equipment that can only be done with circuits being energized.
- The employer can demonstrate that de-energizing introduces additional hazards or increased risk. An example of this might be where work is being done in a hazardous location that requires room ventilation to remain operational to prevent the buildup of toxic fumes.
The importance of arc-rated PPE
Based on NFPA 70E requirements, it is clear that while establishing an ESWC or while performing justified energized work, properly rated arc flash PPE will be required. In essence, this does not leave any scenario where arc-rated PPE will not be needed for employees on some level, which leads to another significant point that is being made in the OSHA arc flash guidance around the use of PPE.
The reality for electricians is that, unless an ESWC has been properly established, there is always a level of risk exposure to arc flash hazards while working on a piece of equipment. Keeping in mind that the 1.2 Cal/cm2 threshold established for the arc flash boundary in NFPA 70E is where an employee could be exposed to second-degree burns, I can’t exactly imagine a person standing in line to get a lesser degree burn, which is still going to be rather unpleasant. Where a flame can be established through an arc flash, that same flame can ignite the clothing worn by the person performing the electrical task.
You would not send a firefighter to combat a wildfire in a gas-soaked suit, so why would we consider it permissible to have electricians on the job site essentially wearing fuel while performing their daily tasks? In their guidance, OSHA suggests that wearing ignitable flammable clothing, such as cotton and nylon, is not appropriate for electricians’ daily wear and that appropriate arc-rated PPE (AR PPE) should be utilized. They further state that employers can reinforce the use of the correct PPE to employees by expressing phrases to them, such as “Don’t wear fuel.”
Connecting the dots
In closing, I want to return to the topic of OSHA’s General Duty Clause that we explored earlier and how, in my personal opinion, it relates to this OSHA arc flash guidance. Ultimately, the General Duty Clause puts the onus on the employer to provide a safe place of employment for their employees that is free from recognized hazards. With the recent guidance that OSHA has provided around arc flash exposure to workers, one could certainly argue that it highlights a known and recognized hazard and conveys that to the employer. Even though the arc flash guidance document states it is not currently being tied to a standard or regulation and does not create any legal obligations, looking at it through the lens of the General Duty Clause might suggest otherwise.
An employer has both a moral and legal obligation, through the General Duty Clause, to keep their employees safe. Working in the electrical contracting industry for the past 30 years (owning my own business for many of them) would suggest to me that the best way to alleviate my own business risk would be to help manage the risk associated with my employees around their exposure to arc flash incidents on the job. Having employees incorporate arc-rated PPE, instead of wearing fuel, into their daily wear and utilizing higher-rated PPE, when the task requires it, seems like a great start to mitigating risk for all involved. Based on their providing recent guidance around protecting employees from arc flash hazards, it would appear that OSHA thinks so, too.
Important Notice: Any opinion expressed in this column is the personal opinion of the author and does not necessarily represent the official position of NFPA or its Technical Committees. In addition, this piece is neither intended nor should it be relied upon to provide professional consultation or services.
