What is an Arc Flash Incident?
An arc flash is a rapid, uncontrolled discharge of high current through an insulating medium, typically air, between two conductors or between a conductor and ground. An arc fault happens when an electrical current deviates from its intended path. Many factors can cause such disruptions, including equipment degradation, environmental contamination, or, most commonly, human error. According to HSE data, around 1,000 electricity-related injuries are reported each year, with approximately 30 fatalities; arc flash incidents represent a significant subset of these severe, yet preventable injuries.
Dangers to Hands
When an arc fault results in an explosive arc flash, the hands are particularly at risk, as they are often the closest part of the body to the hazard.
Two types of injuries can occur:
Direct Thermal Injury: This happens instantaneously, when the energy delivered from an arc flash contacts the skin, causing potentially life-changing burns. Gloves must be able to withstand this energy long enough to prevent second-degree burns.
Secondary Injury: Post Arc flash, a glove that ignites, melts or drips can become the second source of the injury resulting in significant burn injuries.
Arc-rated clothing gets a lot of attention and consideration, but hands are equally exposed, making glove choice essential. Many safety professionals wonder which test matters most: the European EN box test or the North American ASTM F2675 Open Arc test? Both have value, but their approaches differ, affecting which gloves you can truly trust.
The European EN Box Test
The European benchmark, EN 61482-1-2 ‘box test’ is a straightforward standard: material is exposed to a controlled arc inside a small metal chamber at two levels of intensities; arc currents 4kA and 7kA. If the material resists holes, burns or flames under those conditions, it passes. The material can then be designated with an Arc Protection Class (APC): either APC 1 (4 kA) or APC 2 (7 kA).
This standard for protective clothing is familiar and reassuring, but its rigid ‘box’ setup only offers two classifications and doesn’t reflect the full range of real-world arc conditions.
The North American ASTM F2675 Open Arc Test
This standard, widely used in North America, was developed for hand protection and takes a dynamic, performance-based approach, exposing gloves to increasing arc energy until a second-degree burn would occur.
The result is a measured arc rating, expressed in calories per square centimeter (cal/cm²). This rating allows you to directly match gloves to the incident energy calculated in an arc-flash risk assessment – offering greater precision and flexibility. From a safety manager’s point of view, this is advantageous. Rather than simply saying a glove “passed,”
ASTM tells you how much protection it provides. The EN method ensures compliance while
ASTM helps you make more informed, performance-driven choices.
In short: EN is binary, ASTM is nuanced - and when you’re protecting hands from a 20,000°C explosion, nuance matters.