No, there is not a direct correlation between IBC High Hazard H2 & H3 occupancy classifications and NEC Article 500 classifications. IBC H2 occupancy is defined as a building or structure that is used for the storage or handling of highly flammable or combustible materials. This includes occupancies such as gasoline service stations, paint shops, and chemical plants. IBC H3 occupancy is defined as a building or structure that is used for the storage or handling of flammable or combustible materials in moderate quantities. This includes occupancies such as warehouses, retail stores, and office buildings. NEC Class 1 Division 1 location is defined as a location in which ignitable concentrations of flammable gases or vapors are present during normal operation. NEC Class 1 Division 2 location is defined as a location in which ignitable concentrations of flammable gases or vapors are not normally present during normal operation, but may be present occasionally due to leaks or spills.Therefore, an IBC H2 occupancy may be a Class 1 Div 1 location if ignitable concentrations of flammable gases or vapors are present during normal operation. However, it may also be a Class 1 Div 2 location if ignitable concentrations of flammable gases or vapors are not normally present during normal operation, but may be present occasionally due to leaks or spills.Similarly, an IBC H3 occupancy may be a Class 1 Div 2 location if ignitable concentrations of flammable gases or vapors are not normally present during normal operation, but may be present occasionally due to leaks or spills. However, it is unlikely to be a Class 1 Div 1 location, as ignitable concentrations of flammable gases or vapors are not typically present during normal operation in an IBC H3 occupancy.The specific classification of a location must be determined by a qualified person based on a site-specific assessment of the hazards present. Flag for review