Incident energy level (cal/cm2) is the basis for determining arc flash PPE categories.

• A. True
• B. False
• C. Partially true
• D. Not specified

Answer: (A)

The energy an arc flash could deliver, measured in cal/cm2, drives the PPE category you must wear. PPE categories are defined by ranges of incident energy, so estimating or calculating the incident energy at the worker’s location determines which category of arc-rated clothing, face protection, and gloves is required. In practice, a hazard/risk assessment or arc flash study yields an expected incident energy, and the PPE chosen must be rated for at least that energy level. The statement is true because the whole purpose of the categories is to map the protective equipment to the amount of energy the worker could be exposed to. If you tried to rely on something other than incident energy, you wouldn’t have a consistent basis for selecting the appropriate protection, since the categories are specifically tied to cal/cm2 ranges.