What incident can occur if the ATPV is exceeded on a protective fabric?

When the Arc Thermal Performance Value (ATPV) is exceeded on a protective fabric, the potential for a second-degree skin burn injury becomes evident. The ATPV is a measure of the fabric's ability to protect the wearer from the thermal effects of an arc flash. If the incident energy surpasses the ATPV, the protective fabric can no longer provide adequate shielding, leading to direct exposure of the skin to severe thermal energy.

Second-degree burns are characterized by damage that affects both the outer layer (epidermis) and a portion of the underlying layer (dermis) of the skin. These types of burns can result in pain, swelling, and blister formation, indicating a significant thermal injury that could occur when protective clothing fails to meet its performance standards against arc flashes.

In contrast, first-degree burns affect only the outer layer and are generally less severe. Third-degree burns are more extreme, damaging deeper layers of skin and possibly underlying tissues, which is beyond what would typically be caused by the brightness and heat of an arc flash when the ATPV is exceeded. Rashes and irritation are also less severe skin reactions and do not reflect the extent of injury associated with the failure of protective fabric under high thermal exposure.