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If you’ve ever checked the label on an arc flash garment, you’ve likely seen the terms ATPV or EBT — sometimes used interchangeably, but they mean different things. Both values are critical in determining how much protection your flame-resistant (FR) and arc-rated (AR) clothing provides during an electrical arc event.
Arc Thermal Performance Value (ATPV) measures the amount of incident thermal energy (cal/cm²) a fabric can withstand before there’s a 50% chance of causing a second-degree burn.
In simple terms, ATPV represents the heat protection level — the higher the number, the stronger the garment’s resistance.
For example:
ATPV 8 cal/cm² = CAT 2 protection (moderate risk)
ATPV 25 cal/cm² = CAT 3 protection (high risk)
Energy Breakopen Threshold (EBT) is the energy level at which the fabric physically breaks open when exposed to arc heat.
This measurement applies when the fabric does not ignite but tears before reaching the burn threshold.
Like ATPV, the value is expressed in cal/cm², and both ratings are equally acceptable under ASTM F1959 and IEC 61482-1-1 standards.
Neither is “better.” The standard requires that the lower of the two values (ATPV or EBT) be used as the official arc rating printed on the garment label.
This ensures the rating reflects the worst-case performance — providing an honest, safety-first indication of protection.
ATPV and EBT ratings help safety professionals match PPE to real-world hazards. Wearing a garment with too low an arc rating can result in severe burns; too high, and you may sacrifice comfort unnecessarily.
Proper training, hazard assessment, and garment selection are key to compliance with NFPA 70E, EN ISO 11612, and IEC 61482.
At DomexSafety.com, every FR and arc-rated garment is tested to determine accurate ATPV or EBT values under ASTM F1959 and IEC 61482-1-1.
Our products meet EN ISO 11612, EN 1149-5, and NFPA 70E standards — ensuring consistent, certified protection that lasts through industrial laundering and daily use.
