Arc Flash PPE is tested to determine its protective ability, this is called an arc rating. This testing is done on the fabric or a finished product using various different testing methods according to applicable Standards. The ASTM Standards are explained in this article, found in the library section of this website..
There are various different types of arc ratings. In North America, the most popular product options have an ATPV or EBT rating. An arc rating is reported as either ATPV or EBT, whichever is the lower value. The ELIM is a new way to evaluate the arc thermal resistance properties to select PPE with a lower risk of a worker skin burn injury. All of these values are provided in calories per square centimeter (cal/cm2).
ATPV, Arc Thermal Performance Value, the incident energy level at which there is a 50% probability of sufficient heat transfer to cause the onset of a second-degree skin burn injury.
EBT, Breakopen Threshold Energy, the incident energy level at which there is a 50% probability of the formation of holes or tears in the layer closest to the skin.
ELIM, Incident Energy Limit, the highest incident energy data point without breakopen and without reaching the onset of a second-degree skin burn injury