Section 8/Arc Flash Boundary
IEEE 1584 Section 8 covers calculation of the arc flash boundary distance at which incident energy equals 1.2 cal/cm2.
The arc flash boundary is the distance from an arc source at which the incident energy equals 1.2 cal/cm2, the threshold for the onset of a second-degree burn on unprotected skin. Anyone within the arc flash boundary during an arc flash event must be wearing appropriate PPE. The boundary distance is calculated from the same model used for incident energy (Section 4) by solving for the distance at which the energy reaches the 1.2 cal/cm2 threshold.
Why this section exists
The arc flash boundary defines the safety perimeter around energized equipment. Outside this boundary, an unprotected person would not receive second-degree burns from an arc flash event. Inside the boundary, PPE is mandatory. The boundary distance helps facility managers and safety coordinators establish work zones, barricading requirements, and PPE staging areas. Larger boundaries indicate higher hazard levels.
What plan reviewers look for
Plan reviewers check arc flash studies for the boundary distance at each piece of equipment. For facility layout drawings, they verify that the arc flash boundary does not extend into public areas or adjacent work zones where unprotected personnel may be present. They check that the boundary is documented on the arc flash labels per NEC 110.16.
Common violations
Related IEEE 1584 requirements
Section 4 covers the incident energy calculation model. NFPA 70E Section 130.5 requires the arc flash risk assessment including the boundary determination. NFPA 70E Section 130.7 covers PPE selection for work within the boundary. NEC 110.16 requires arc flash labels that should include the boundary distance.