Arc Flash Statistics: Incident Frequency, Injury Data, and Costs

Arc Flash Statistics at a Glance

Why Arc Flash Incidents Are Hard to Count

Arc flash is one of the most heavily cited hazards in industrial safety marketing, and one of the least reliably counted. The reason is structural. The Bureau of Labor Statistics tracks electrical injuries and fatalities in aggregate, but its event codes do not isolate arc flash from electric shock. OSHA and NIOSH publish detailed investigation reports that do identify arc flash, but only for the small minority of incidents that trigger a federal investigation. The Department of Energy maintains an incident database that is not accessible to the public.

A 2024 analysis by Qi Tong and Thomas Gernay at Johns Hopkins University worked through this problem directly. Reviewing OSHA and NIOSH investigation reports from the early 1980s through 2022, the researchers identified 1,291 reports relevant to arc flash events, covering 1,823 injuries and 277 fatalities. They estimated that OSHA and NIOSH investigation records capture approximately 3 to 10 percent of the electrical injuries reported in BLS data each year, which means the true annual count of arc flash injuries is several times larger than what appears in any public investigation record.

The study was supported by Schneider Electric USA; the authors state the conclusions are their own. Reliable notes the funding here for transparency, and the study’s core value is its method, which relies entirely on public OSHA and NIOSH records that anyone can re-examine.

Applying the ratio between BLS injury counts and OSHA-reported cases, the report estimated roughly 630 electric arc incidents per year in the United States, with an approximate range of 350 to 1,050, and the authors frame this as an approximation that is likely still an undercount. Treat that number as a floor derived from reporting ratios rather than a measured count. It reflects incidents serious enough to enter federal statistics, and it excludes events that damaged equipment without injuring anyone, which by most practitioner accounts is the majority of arc flash events.

The “5 to 10 arc flash explosions per day” figure

The most widely repeated arc flash statistic holds that 5 to 10 arc flash explosions occur in electrical equipment every day in the United States. That figure appears in PPE catalogs, training materials, and vendor white papers, usually without attribution. The Fire Protection Research Foundation’s own 2015 report on electrical injury, prepared for the NFPA 70E Technical Committee, describes it as “a common estimate” and states plainly that the origins of the estimate are unclear, citing a 2007 NIOSH paper that made the same observation. If the number is accurate, no publicly available dataset confirms it. Any page or presentation that states it as established fact is repeating a citation chain with no primary source at the bottom.

Workplace Electrical Injury and Fatality Data

Arc flash is a subset of workplace electrical incidents, so the electrical injury baseline matters for context. The Electrical Safety Foundation International compiles BLS data annually. Its January 2026 compilation, covering 2011 through 2024, counts 2,070 workplace fatalities from contact with or exposure to electricity out of 70,276 occupational fatalities from all causes, an average of roughly 150 electrical fatalities per year.

Three findings from the ESFI compilation are directly relevant to arc flash risk in industrial plants:

ESFI’s analysis of OSHA 170 fatality reports found that 70 percent of reported workplace electrical fatalities between 2011 and 2024 (1,163 fatalities) occurred in non-electrical occupations. Maintenance mechanics, operators, laborers, and grounds workers die from electrical contact far more often than electricians do, which is the core argument for extending electrical safety training beyond the electrical department.

The same OSHA 170 analysis breaks fatalities down by cause. Overhead power line contact leads at 49 percent, followed by unexpected contact with energy at 20 percent and contact with nearby energized equipment at 12 percent. ESFI’s OSHA 170 cause coding lists 26 fatalities, or 2 percent of reported workplace electrical fatalities from 2011 to 2024, in its arc-flash category; ESFI notes that this category excludes overhead power-line related incidents. That low share reflects the nature of the hazard: arc flash injures far more often than it kills, and its burden shows up in burn admissions and hospital stays rather than in the fatality census.

Construction and extraction occupations, installation, maintenance, and repair occupations, and building and grounds cleaning and maintenance occupations have the highest electrical fatality rates.

Non-fatal electrical injuries involving days away from work totaled 5,180 in 2023 and 2024 combined, a 59 percent increase over the prior two-year period, after 3,260 in 2021 and 2022. BLS reports non-fatal data in two-year cycles, so year-over-year noise is expected, but the direction reversed after a decade of general decline.

The longer trend is genuinely positive. The Fire Protection Research Foundation’s 2015 analysis of BLS data counted 5,587 fatal electrical injuries between 1992 and 2013, with the annual total falling from 334 in 1992 to 139 in 2013, a decline of more than half. Electrical fatality rates have since held roughly flat at approximately 0.1 per 100,000 workers.

What Share of Electrical Injuries Are Arc Flash?

Because BLS does not code arc flash separately, the best available evidence on the arc flash share of electrical injuries comes from burn center admission studies, compiled in the Fire Protection Research Foundation report:

Two details from these studies deserve more attention than they get. In the Texas series, arc injuries had the lowest mortality of the electrical burn groups but the largest burn size, meaning survivors face long hospitalizations and reconstruction. And in the Ontario research, the most common lasting consequences of electrical injury were neurological and psychological symptoms, including memory problems, chronic pain, anxiety, and insomnia, many of which did not appear until months after the injury. Burn statistics understate the total injury burden.

What Causes Arc Flash Incidents

The most detailed cause data comes from NIOSH research on the mining industry, which examined 836 noncontact electric arc burn incidents recorded by MSHA between 1990 and 2001. Electricians accounted for 39 percent of injuries and mechanics 20 percent. Most events occurred during electrical maintenance or repair work, but a follow-up paper by the same authors found that 19 percent of arcing events occurred during normal operation of equipment, frequently involving failures of components such as circuit breakers. Where voltage was reported, 84 percent of arcing events involved 600 volts or less.

Research on PPE performance reinforces the human-factors picture. A 2010 study by Doan and co-authors examined 40 arc flash incidents involving 54 workers and found that two thirds of injured workers had not conducted an arc flash analysis before the task, and that wearing an arc-rated face shield and leather gloves with sleeve overlap would have prevented 39 percent of the observed burn injuries. The Johns Hopkins analysis reached a consistent conclusion from its incident database: the most common error precursors were failure to use proper PPE and failure to de-energize equipment.

Low voltage does not mean low hazard, but the OSHA investigation record suggests it is harder to sustain a damaging arc at the bottom of the range. A 2012 analysis of OSHA arc flash investigations by Wellman found injuries from arc flashes at 120 to 277 volts, while only 6 percent of burns from exposures below 1,000 volts were produced at 300 volts or less. The same analysis concluded that every injury in the dataset could have been prevented by de-energizing the equipment.

What Arc Flash Incidents Cost

Round-dollar averages dominate arc flash marketing. Figures such as an average incident cost of $1.5 million circulate widely without a traceable primary source, and the honest answer is that no statistically representative average cost per arc flash incident has been published. What exists instead is a small set of documented cost studies, each with a narrow scope, compiled in the Fire Protection Research Foundation report:

The spread across these estimates is not sloppiness, it reflects scope. Workers’ compensation claims capture medical costs and wage replacement. Utility case studies add replacement labor, equipment, and lost productivity. Total-cost models layer indirect costs on top, and the multiplier chosen drives the result: published indirect-to-direct ratios for workplace injury range from roughly 1.1:1 for high-direct-cost injuries (the Business Roundtable ratios OSHA has used) up to a 20:1 estimate from the American Society of Safety Engineers, with a 4:1 ratio sometimes treated as a conservative standard. Any arc flash cost figure quoted without its scope attached is a marketing number, not a benchmark.

What can be said with confidence is directional. Electrical burn injuries produce longer hospital stays and more operations than most workplace injuries, arc flash survivors in the Texas burn series stayed a mean of 11.3 days, and the neurological and psychological sequelae documented in the Ontario research extend costs well past discharge. For fatality exposure, OSHA’s own rulemaking valuations put the figure at $8.7 million per life saved and $62,000 per nonfatal injury prevented, which are the numbers that belong in a risk-reduction justification, not an unsourced incident average.

The Physics Behind the Injury Data

Two physical reference points anchor most arc flash safety engineering. Ralph Lee’s 1982 paper, the foundational work on arc flash burns, calculated that arc terminal temperatures can reach approximately 35,000 degrees Fahrenheit, with lethal burns possible several feet from the arc and clothing ignition from expelled molten metal droplets at 1,000 degrees Celsius or more. And an incident energy density of 1.2 calories per square centimeter on exposed skin is the accepted threshold for the onset of second-degree burns, the boundary condition used in arc flash hazard calculations under IEEE 1584 and PPE selection under NFPA 70E.

Regulatory Context

OSHA does not publish a standard titled “arc flash.” Enforcement runs through the electrical safety-related work practices requirements (29 CFR 1910.331 to 335), the electric power generation, transmission, and distribution standard (29 CFR 1910.269), PPE requirements, and the General Duty Clause. NFPA 70E, first issued in 1979, is the consensus standard OSHA references for safe electrical work practices, including arc flash risk assessment, approach boundaries, and arc-rated PPE categories.

NFPA 70B, Standard for Electrical Equipment Maintenance, changed from a recommended practice to a standard in 2023, shifting its language on electrical maintenance activities that reduce arc flash likelihood, such as periodic inspection and testing of protective devices, from “should” to “shall.” Whether those requirements are enforceable in a given facility depends on how 70B is applied there: adoption or incorporation by an authority having jurisdiction, use by a regulator, insurer requirements, or contract terms.

The maintenance connection is the part reliability teams should internalize. The NIOSH mining research found that a meaningful share of arc events, 19 percent, occurred during normal operation, often triggered by equipment failure. Arc flash is not purely a work-practices problem; it is partly an asset condition problem, which places protective device maintenance, thermographic inspection, and switchgear condition assessment inside the arc flash prevention program rather than adjacent to it.

Why Published Arc Flash Figures Vary

Treat every arc flash statistic as an estimate with a scope, for four reasons.

First, no comprehensive incident database exists. BLS aggregates electrical injuries without an arc flash code, OSHA and NIOSH investigate a small fraction of cases, and the DOE database is not public.

Second, several of the most-quoted figures have no traceable primary source. The 5 to 10 incidents per day estimate is the clearest example, and figures such as thousands of arc flash burn admissions per year are generally attributed to proprietary consulting research that has not been published in an independently examinable form.

Third, definitions differ. Some datasets count arc flash injuries only, others count all electrical burns, and others count electrical incidents of every type. A 55 percent arc flash share of electrical burn admissions at one burn center and a 34 percent share at another partly reflects referral patterns and coding, not just underlying risk.

Fourth, cost figures depend entirely on scope and multipliers, as covered above.

For plant-level decision making, the defensible position is that arc flash incidents are far more frequent than federal investigation records show, that most electrical fatalities strike workers outside electrical occupations, and that documented per-claim workers’ compensation costs for serious arc flash burns run in the tens of thousands of dollars with total incident costs reaching multiples of that once indirect costs are included.

Frequently Asked Questions

How many arc flash incidents occur each year in the United States?

No comprehensive count exists. A Johns Hopkins University analysis identified 1,291 OSHA and NIOSH investigation reports covering arc flash events from the early 1980s through 2022, with 1,823 injuries and 277 fatalities, and estimated that OSHA and NIOSH investigation records capture approximately 3 to 10 percent of the electrical injuries reported in BLS data. The report estimated roughly 630 electric arc incidents per year, with an approximate range of 350 to 1,050, framed as an approximation that is likely still an undercount, and that figure excludes incidents that damage equipment without injuring anyone.

Is the claim that 5 to 10 arc flash explosions happen every day accurate?

The figure has no traceable primary source. The Fire Protection Research Foundation’s 2015 report for the NFPA 70E Technical Committee describes it as a common estimate whose origins are unclear. It may be plausible once equipment-only events are included, but no public dataset supports it.

How many workers die from electrical incidents each year?

BLS data compiled by the Electrical Safety Foundation International show 2,070 workplace electrical fatalities from 2011 through 2024, an average of roughly 150 per year. ESFI’s analysis of OSHA 170 fatality reports found 70 percent of reported electrical fatalities over that period occurred in non-electrical occupations.

What percentage of electrical injuries are arc flash?

Burn center studies attribute 34 to 55 percent of work-related electrical burn admissions to arc flash rather than direct contact. BLS injury codes do not separate arc flash from shock, so no economy-wide percentage exists.

What does an arc flash incident cost?

No representative average has been published. Documented figures include Washington State workers’ compensation data showing over $1.3 million across 30 serious arc flash burn claims (roughly $43,000 per claim, unadjusted), a utility case study averaging $49,823 per electrical injury in 1994 dollars, and a total-cost model reaching $15.75 million per serious injury in 1998 dollars once indirect costs are included. OSHA’s 2014 rulemaking valued each prevented nonfatal injury at $62,000 and each life saved at $8.7 million. Scope drives the number.

What causes most arc flash incidents?

Human factors dominate the investigation record: failure to de-energize equipment and failure to use appropriate PPE are the most common error precursors in the Johns Hopkins incident database, and a study of 40 arc flash incidents found two thirds of injured workers had not performed an arc flash analysis before the task. Equipment condition matters too: NIOSH mining research found 19 percent of arc events occurred during normal operation, often initiated by component failure.

Sources

• Tong, Q. and Gernay, T. “Arc Flash Incidents in Non-Residential Buildings: Data Analysis.” Johns Hopkins University, 2024. Study supported by Schneider Electric USA; the authors state the conclusions are their own. (JScholarship repository)
• Campbell, R.B. and Dini, D.A. “Occupational Injuries From Electrical Shock and Arc Flash Events.” Fire Protection Research Foundation, March 2015.
• Electrical Safety Foundation International. “Workplace Injury and Fatality Statistics,” compilations of BLS CFOI and SOII data and OSHA 170 fatality reports, 2011 to 2024 (compiled January 2026).
• U.S. Bureau of Labor Statistics. Census of Fatal Occupational Injuries; Survey of Occupational Injuries and Illnesses.
• Homce, G.T. and Cawley, J.C. NIOSH research on noncontact electric arc burn incidents in mining, MSHA data 1990 to 2001; Cawley, J.C. and Homce, G.T., 2007.
• Kowalski-Trakofler, K.M. and Barrett, E.A. NIOSH follow-up research on behavioral and organizational factors in arc flash incidents, 2007.
• Doan, D. et al. Study of PPE performance in 40 arc flash incidents involving 54 workers, 2010.
• Wellman, C. Analysis of OSHA arc flash investigation data, 2012.
• Brandt, M. et al., 2002; Arnoldo, B. et al., 2004; Singerman, J. et al., 2008. Burn center studies of work-related electrical injury, as compiled in Campbell and Dini, 2015.
• Washington State Department of Labor and Industries. “Burn Injury Facts,” 2006.
• Lutton, 1994; Wyzga, R. and Lindroos, W., 1999. Electrical injury cost studies, as compiled in Campbell and Dini, 2015.
• OSHA. Final rule, Electric Power Generation, Transmission, and Distribution; Electrical Protective Equipment (29 CFR 1910.269 and 29 CFR Part 1926, Subpart V), Federal Register, 2014.
• Lee, R.H. “The Other Electrical Hazard: Electric Arc Blast Burns.” IEEE Transactions on Industry Applications, 1982.
• NFPA 70E, Standard for Electrical Safety in the Workplace. NFPA 70B, Standard for Electrical Equipment Maintenance, 2023 edition.
• OSHA. “Protecting Employees from Electric-Arc Flash Hazards,” Publication 4472, 2024.