What is an acceptable type of head protection when the back of the head is within the arc flash boundary and the incident energy is 12 cal/cm2 or less?

An arc-rated balaclava with a faceshield is considered acceptable head protection in this scenario because it offers both thermal protection from the incident energy and coverage for the head and face. When working within the arc flash boundary, especially where the incident energy is significant—such as 12 cal/cm² or less—it's crucial to have head protection designed specifically for arc flash hazards.

The balaclava provides coverage for the neck and additional thermal protection for the head, which is essential for ensuring that the worker is safeguarded against the heat generated by an arc flash. The faceshield enhances visibility while also safeguarding the face from potential thermal and physical hazards associated with an arc flash event.

In contrast, options such as an arc-rated faceshield only may lack sufficient head protection coverage. A hard hat with a face shield, while offering some protection, might not provide adequate thermal insulation against the defined level of incident energy. Similarly, a standard hard hat does not offer arc-rated protection necessary for environments where arc flash risks are present, failing to meet the safety standards required by NFPA 70E for such situations.