Arc flash safety guidance mainly comes from which source that helps determine PPE and boundary?

• A. The crane manufacturer's manual
• B. OSHA general industry standards
• C. NFPA 70E hazard analysis and equipment data
• D. Local fire department guidelines

Answer: (C)

Arc flash PPE and the protective boundary come from applying NFPA 70E through an arc flash hazard analysis. This standard provides the method to determine the incident energy at a worker’s location by using data from the equipment—such as system voltage, available fault current, and protection characteristics—to calculate how much energy an arc could release. From that analysis, you select the appropriate arc-rated PPE and establish the arc flash boundary distances needed to stay safe. The other options don’t offer this electrical hazard-analysis framework or the specific PPE/boundary guidance: a crane manufacturer’s manual isn’t about electrical arc hazards, local fire department guidelines aren’t the technical basis for PPE selection, and while OSHA general industry standards govern safety overall, the explicit PPE levels and boundary determinations come from NFPA 70E hazard analysis aided by equipment data.