Technically speaking, an arc flash is an electrical breakdown of the resistance of air resulting in an electric arc that can occur where there is sufficient voltage in an electrical system and a path to ground or lower voltage. In more layman’s terms, an arc flash is a short circuit that flashes from one exposed live conductor to another, or to ground. The resulting ionized air creates superheated plasma that can reach temperatures of 5,000° F and can result in considerable damage, including fire and/or injury. For this reason, it is important that all individuals who work on electrical systems wear appropriate arc flash personal protective equipment (PPE).
Although many organizations sell arc flash apparel individually (i.e., all items of clothing are sold separately), the trend of packaging arc flash clothing and accessories in convenient arc flash kits continues to grow. These intuitive kits include all of the necessary PPE garments and accessories to ensure worker safety: head protection, hand protection and garments.
Flame-resistant clothing, when sold in an arc flash kit, is often purchased as task-oriented clothing. A user may put on arc flash PPE - a short coat, bib overalls, gloves and an arc flash hood - over an existing uniform or shirt and pant to perform a specific task, and then take off these items after completing the task. In the case of putting on a high voltage arc flash suit, an employee is putting on more than five pieces of PPE, specific to the task at hand. “Kitting” the arc flash gear necessary for a task at a certain hazard risk level ensures that all equipment necessary for worker protection is readily available, and most importantly, worn.
Arc flash kits provide flame resistance and arc protection in a wide range of arc ratings. This allows you to get as close as possible to a rating that may have been identified by an arc flash assessment without adding unnecessary weight to your workers. In the case of hazard risk category two (HRC2), as defined by NFPA 70E®: Standard for Electrical Safety in the Workplace, an arc flash kit that achieves the HRC2 minimum 8 cal/cm2, may weigh 6-7 ounces per square yard; whereas a garment that achieves the maximum arc rating for HRC2, 24 cal/cm2, is going to be much heavier - 13 ounces per square yard or more. This is a noticeable difference when lifting the garment, and is certainly noticeable when wearing the garment in a high-temperature environment.
Common types of fabric used for arc flash kit garments include: