SafetyQuestion 428 of 521
An arc-flash study shows an available incident energy of 8 cal/cm² at the working distance. The arc-rated clothing and PPE must have an arc rating of:
a.Less than the incident energy so it breathes better
b.Exactly 1.2 cal/cm²
c.At least equal to or greater than the available incident energy (8 cal/cm² or more)
d.Any untreated cotton clothing is acceptable
Explanation
Arc-rated PPE must have an arc rating equal to or greater than the available incident energy—here at least 8 cal/cm². Choosing PPE below the incident energy, or ordinary cotton (which can ignite), would not protect the worker. The 1.2 cal/cm² figure is the arc flash boundary threshold, not a PPE rating for this task.
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