Electricity is essential but dangerous. For workers in electrical, industrial, maintenance, and fabrication settings, two of the most serious electrical hazards are arc flash and electrical shock. Understanding how they differ, their risks, and how to protect against them is critical for safety.
In this article we’ll cover:
- What is an arc flash, and what is electrical shock
- The differences in mechanisms, consequences, and exposure
- OSHA standards and guidance
- Protective gear and best practices (with Novarlo product recommendations)
What Is Electrical Shock?
Electrical shock occurs when your body becomes part of an electrical circuit current flows through you. This may happen via contact with live conductors, faulty insulation, or grounding paths. The severity depends on factors such as:
- Voltage and current level
- Path through the body (hand-to-hand, hand-to-foot, through the heart)
- Duration of exposure
- Body resistance (skin moisture, cuts, contact area)
Even relatively low voltages (50 V and up) can be hazardous. OSHA considers all voltages above 50 V potentially dangerous when the shock can cause injury.
Potential effects of electrical shock include:
- Burns at entry/exit points
- Muscle contraction, making it impossible to let go
- Cardiac arrest, arrhythmia, or internal organ damage
- Secondary injuries (falls, blunt trauma)
- Nervous system damage
OSHA covers electrical safety in its general industry standards (29 CFR 1910 Subpart S) and requirements for insulating and protective equipment (29 CFR 1910.137)
What Is an Arc Flash?
An arc flash is an explosive release of energy caused by an electrical fault between conductors or between a conductor and ground. When an arc is initiated, extreme heat, light, pressure, and even molten metal and shrapnel can result.
Key features:
- Temperatures can exceed 35,000 °F (19,400 °C), enough to vaporize metals and ignite clothing.
- Bright flash of light (UV/IR)
- Concussive blast, sound waves
- Ejected molten metal, debris
- Pressure wave and possible hearing damage
Unlike shock, which is a current flowing through the body, an arc flash is more like a small explosion or thermal event that can injure from proximity. Many arc flash injuries come from ignited or melting clothing rather than direct contact with the arc itself.
OSHA addresses arc flash hazards in its guidance: for example, requiring proper PPE for face and eyes when arc or flash hazards are present (29 CFR 1910.335)
Key Differences: Shock vs. Arc Flash
Here’s a comparison:
|
Feature |
Electrical Shock |
Arc Flash |
|
Mechanism |
Current through body |
Electrical fault arc, thermal/pressure event |
|
Path of harm |
Inside body (heart, nerves) |
External thermal burns, blast injury, molten debris |
|
Distance factor |
Must touch or contact |
Can injure at a distance (within arc boundary) |
|
Ignition risk |
May burn contact points |
Can ignite clothing, vaporize metal |
|
Protective strategies |
Insulation, isolation, safe boundaries |
Arc-rated PPE, de-energization, flash boundaries |
OSHA & Regulatory Guidance
De-energize whenever possible
According to OSHA 29 CFR 1910.333(a)(1), live parts should be de-energized before work unless doing so creates additional hazards. This basic safe-work practice reduces both shock and arc risk.
PPE & Work Practices
- OSHA’s Protecting Employees from Electric-Arc Flash Hazards guidance emphasizes use of arc-rated, flame-resistant (FR) clothing and PPE for exposed workers and creating restricted and limited approach boundaries.
- PPE for eyes and face must be used “whenever there is danger of injury to the eyes or face from electric arcs or flashes or from flying objects” under 29 CFR 1910.335(a)(1)(v)
- OSHA has updated its guidance to emphasize that even low-voltage systems (e.g. 120/208 V) can produce arc flashes severe enough to cause burns or ignite clothing, reinforcing that energized work requires PPE.
- OSHA also calls for employers to conduct arc flash risk assessments and include arc flash hazards within their safety and health program.
Injury Mechanisms & Risks
For Electrical Shock:
- When body resistance is lower (wet skin, wounds), current flows more easily.
- Shocks can “freeze” a person in contact, making it hard to let go of the source. Secondary harm (falls) are common.
- Burns are usually localized at entry and exit points; but internal damage (muscles, organs) may not be visible.
For Arc Flash:
- Intense thermal exposure can cause deep tissue burns.
- The explosion pressure can cause blunt trauma or rupture of eardrums or lungs.
- Molten metal or debris can strike skin or unprotected parts, causing severe second- or third-degree burns.
- The UV/IR flash can injure the cornea or cause “flash burn” to eyes.
- The resulting irreversible damage is often worse than a shock arc flash events are among the most devastating electrical hazards known.
How to Protect Yourself & Your Workforce
Engineering & Administrative Controls
- De-energize equipment before working (lockout/tagout)
- Use remote switching, barrier guards, insulating covers
- Design electrical systems to minimize arc risk (fault limiting, zone protection)
- Conduct arc flash hazard assessments to define incident energy, arc boundaries, and required PPE
- Mark equipment with calculated incident energy values or required PPE categories
Use Proper PPE
When working near energized or potentially energized parts, appropriate PPE is essential. Below are Novarlo products you can link in your article:
- Enespro AGP 40 Cal Arc Flash Kit With Lift Front Hoods— a full arc flash protection kit including helmet, FR apparel, voltage gloves, face shield, and more
- ArcGuard 40 cal CAT 4 Arc Flash Kit — designed for higher-energy environments with lift-front hood and full arc-rated clothing
- Enespro ArcGuard Class 2 Voltage Glove Kit — insulating gloves rated for medium-voltage work
- AG Safety Electrical Insulating Roll Blanket — insulating blanket for barring or covering live parts safely
- Enespro 55 Cal Arc Flash Kit (CAT 4) - Jacket/Bib, Dual Fan Hood — a full arc flash protection kit including a dual hood fans provide a gentle breeze that keeps operator cool and decreases lens fogging
Make sure to select PPE with arc ratings exceeding the calculated incident energy for your work environment.
Take Charge of Electrical Safety with the Right PPE
Differentiating arc flash from electrical shock is not just academic it’s lifesaving. While both stem from electricity, their mechanisms, hazards, and required protections differ dramatically. Proper engineering controls, safe procedures, and arc-rated PPE are essential.
At Novarlo, we offer high-quality, rated electrical safety gear you can trust:
- Browse our Arc Flash & Electrical Safety lineup
- Use the kits, gloves, hoods, and insulating blankets above in your safety programs
- Ensure your team is trained and your procedures meet OSHA & industry best practices