An arc flash is an electrical release of energy hotter than the surface of the sun and capable of exploding with the strength of eight sticks of dynamite. It is reported that arc flash incidents kill about two workers a day. An arc flash can be caused by:

• Coming too close to a high-amp source with a conductive object.
• Dropping a tool or otherwise creating a spark.
• Equipment failure from using substandard parts, improper installation, or even normal wear and tear.
• Insulation breaks and gaps.
• Dust, corrosion, and other impurities on the conductor’s surface.

Arc flash injuries can result in severe skin burns. Since arc incidents may occur when performing routine maintenance, emergency responders and firefighters must understand the safe approach distances to exposed electrical conductors and understand the value of wearing arc PPE.

In temperatures related to arc flash incidents, even FR clothing can break open due to the extreme energy. For arc flash protection, you need clothing that is compliant with NFPA 70E - Current Edition and that meets performance specifications of ASTM‑F1506. This clothing will have a Hazard Risk Category rating (HRC) from Level 1 to Level 4. The HRC corresponds to the ATPV (Arc Thermal Performance Value), which indicates the amount of thermal energy the apparel protects against. More specifically, the ATPV represents the maximum incident thermal energy in units of energy per surface area (e.g. kJ/m² or cal/cm²) that a fabric can support before the wearer will suffer 2^nd degree burns.