In this episode of EC&M Code Conversations, Editor-in-Chief Ellen Parson and Code Consultant Russ LeBlanc discuss 2026 NEC changes related to an expanded requirement regarding arc flash hazard marking in other than dwelling units. Russ explains the major expansion to Sec. 110.16 and what changed with the arc-flash labeling requirements. He also explains why he thinks this might be the biggest change in the 2026 NEC.