NEC, NESC, NFPA 70E, and Arc Rated PPE: A Quick Look at Electrical Industry Standards
General 06 Jan 2020
Throughout the electrical industry, consensus standards provide critical information advising how to safeguard employees facing arc flash hazards. These standards—NEC, NESC, and NFPA 70E—are all meant to guide safety initiatives, but which one is relevant for you? We break down each standard and what they mean for your workplace.
National Electrical Code (NEC) is the standard governing electrical wiring and equipment installation. Published by the National Fire Protection Association (NFPA), this standard focuses on unenergized wiring and equipment installation. Until the system is installed and fully energized, the arc flash hazard does not apply; therefore, this standard does not cover and does not assist in arc-rated (AR) personal protective equipment (PPE) selection.
National Electrical Safety Code (NESC) is published by the Institute of Electrical and Electronics Engineers (IEEE) and approved by the American National Standards Institute (ANSI). NESC provides guidance on safely installing, operating, and maintaining electric power and communication utility systems that supply residential, commercial, and industrial buildings. Within NESC, there are two methods guiding AR PPE selection:
- Those in generation facilities working with 15 kV and below should refer to IEEE-1584 to calculate a site’s arc flash hazard risk and to develop a plan to mitigate said risk, which may include AR PPE.
- Those working with transmission and distribution systems generating 15 kV or more typically utilize the NESC table method to calculate arc flash hazard risk and to guide AR PPE selection.
NESC requires workers to wear AR PPE with an arc rating exceeding the calculated arc flash hazard. If the incident energy is greater than 2 cal/cm2, AR PPE is required; however, if the incident energy is less than 2 cal/cm2, workers can instead wear cotton work garments.
National Fire Protection Association (NFPA) 70E is the standard for electrical safety in the workplace. This standard, used primarily for electrical safety in industrial workplaces, states that employees must wear AR PPE that meets ASTM F1506 requirements if there is a risk of second-degree burns from an arc flash exposure of 1.2 cal/cm2 or higher. A risk assessment will indicate the likelihood and potential severity of an arc flash incident, which correlates to appropriate AR PPE selection. If the risk assessment determines the incident energy is less than 1.2 cal/cm2, it may be safe to wear cotton work garments.
No matter the situation, safety precautions should be taken to help reduce the likelihood of an arc flash incident and to mitigate the severity of injury if an incident occurs. Flame resistant, arc rated PPE is a critical safety precaution serving as the final layer of defense against a variety of short-term thermal duration hazards—from electrical industry needs to industrial occupation safety tools. While not a suit of armor, AR PPE can help mitigate potentially life-threatening injuries for greater piece of mind when incorporated into a holistic safety program.