Frequently Asked Questions

An arc flash is a sudden release of energy caused by an electrical fault. It generates extreme heat, intense light, and a powerful pressure wave, potentially resulting in severe injuries or fatalities. Arc flash hazards are risks associated with these events and include burns, hearing damage, and secondary damage from falls or equipment.

NFPA 70E is the Standard for Electrical Safety in the Workplace, published by the National Fire Protection Association (NFPA). It provides guidelines for safe work practices to protect workers from electrical hazards like shock, electrocution, arc flash, and arc blast. NFPA 70E® is essential because it helps employers meet OSHA’s requirements for providing a safe workplace and reduces the risk of electrical incidents.

Several variables affect the amount of energy released in an arc flash. The two most influential factors are fault current and time.  Fault current is determined by starting with what the utility is able to contribute. It then increases or decreases as it goes through the system. The amount of time a fault takes to clear will be determined by the protective device (fuse or breaker).

All three of these documents are standards published by the National Fire Protection Association (NFPA). These three standards cover electrical installations. NFPA 70 covers how to build and install an electrical system. NFPA® 70B is a standard for how to maintain an electrical system. NFPA 70E® is the standard for how to safely work around electrical systems.

An electrically safe work condition is a state where an electrical circuit or equipment is completely de-energized, verified, and locked out or tagged out. This eliminates potential hazards from energized components, ensuring the safety of workers performing maintenance or repair tasks.

NFPA 70E defines three key boundaries. The first two are related to electric shock, while the third is related to arc flash. Those boundaries are: 1. Limited Approach Boundary - The distance at which unqualified persons must stay to avoid electrical shock. 2. Restricted Approach Boundary - The distance where only qualified persons with appropriate PPE can enter. 3. Arc Flash Boundary - The distance where a worker could receive a second-degree burn from an arc flash.

Electrical equipment must have arc flash labels indicating: • Nominal system voltage. • Arc flash boundary. At least one of the following: 1. Available incident energy and the corresponding working distance; or the arc flash PPE category in Table 130.7(C)(15)(a) or Table 130.7(C)(15)(b) for the equipment, but not both 2. Minimum arc rating of clothing 3. Site-specific level of PPE Though not required, it is recommended that the label include information about shock protection boundaries. These labels help workers assess risks and take appropriate precautions.

Incident energy analysis calculates the energy level at a specific distance from an electrical arc fault. It also determines how far away someone could be affected from this fault. It allows you to determine the PPE required to protect workers from burns in the event of an arc flash. NFPA 70E mandates this analysis to ensure adequate protection in high-risk areas.

PPE requirements depend on the incident energy levels and tasks performed. Typical PPE includes: Any time there is a shock hazard: • Insulated gloves and tools. • Class E hard hats and EH rated footwear Any time there is an arc flash hazard: • Arc-rated clothing (suits, gloves, and hoods), and appropriate undergarments. • Face shields and safety glasses. The appropriate PPE level is determined through an arc flash risk assessment.

An electrical risk assessment identifies and evaluates electrical hazards, including shock and arc flash risks. It determines the likelihood and severity of potential incidents and helps establish controls to mitigate those risks, such as proper PPE, safe work practices, and equipment maintenance.

No, unqualified workers cannot perform tasks near or on electrical equipment (that is exposed and energized) unless it is verified to be in an electrically safe condition. They can only work within the Limited Approach Boundary under strict supervision and with training on electrical safety basics.

NFPA 70E® requires workers exposed to electrical hazards at a minimum to undergo training on: • Safe work practices. • Recognizing electrical hazards. • Proper use of PPE and tools. • Emergency procedures. Training must be refreshed every three years or when regulations or job conditions change.