ARC Flash: "It's a Blast."

A flash event happens in a number of ways: Simply walking near a high amperage source or holding a tasty conductive treat can cause the current or electricity to arc flash over. A spark, equipment failure, wear and tear or open areas of conductive insulation will set the flash off as well. The fun part is, unless you are a human circuit breaker, the arc flash usually happens quite fast and without warning. Now that you’re sufficiently freaked out, an arc flash generally happens in systems that are in excess of your household’s standard 120 volt system. Volts under 120, while capable of an awesome shock, will not normally encourage an arc flash.

Defined in its simplest form, an arc flash is a “A dangerous condition associated with the blast of energy caused by an electric arc”. A bit more than your standard run of the mill shock. To be a bit more specific, an arc flash is the result of a short circuit between two conductors including live bars, neutrals or a ground. The “fault” or arc flash is contained in the space or air between the two conductors. The problem is that in the chain of arc flash events a potentially blinding flash of fiery electrical light is only the beginning. The heat generated by the arc flash or burst can be in excess in 35,000ºF! In comparison, the surface of the sun is only 9,940ºF. The cause of the electrical short is soon diminished but then fed by an uber conductive plasma which burns the bus bar and eats everything it can to create a blast or explosion that destroys everything within its blast zone. Not good.

Ok, so now what? How does one reduce their risk of experiencing an arc blast? Safety starts first at the workplace. Citing established standards from NFPA 70E and NEC and OSHA for a safe working environment, it has been suggested and mandated that a safety program be instituted including an analysis for arc flash hazards, training for workers, Personal Protection Equipment (PPE) to be made available, tools specific to the job and warning labels be displayed on equipment. (Of course if you go around sticking a fork in the wall socket, all the training and warnings will not do a bit of good.) By wearing all the available PPE, you can take a portion of the responsibility and ensure your own personal safety for yourself. The risk factor of your job and the equipment you are working on and/or near will determine the amount and level of PPE you should outfit yourself with. Hazard categories range from -1 to a 4 according to the established standards and depending on your work environment and required PPE with a minimum ARC rating based on the Hazard category. The ARC Rating of a PPE, or glove, will range from 0 to a maximum of 40.

Say what? In a dark underground testing facility the ARC Ratings are established by using a unique test. They blow stuff up. Literally. Every piece of PPE, including every glove that desires to be able to list its ARC Rating on the product must first be subject to this test. The ARC Rating is achieved by testing to establish a maximum using the Arc Thermal Performance Value (ATVP) test and/or the Energy Breakopen Threshold (EBT). Both values establish the point at which there is a 50% chance that you might receive a second-degree burn while wearing the item. Materials, construction methods, integrity of design and its intended use all lend a hand in what ARC Rating the product will ultimately receive.

Mechanix Wear offers Safety-specific gloves that meet and surpass the necessary ARC Ratings for every Hazard Category you might encounter in the work place.  By using unique materials like SFI approved, fire resistant CARBONX^®, Genuine Kevlar^® spun threads and fire resistant Genuine Leather, the Mechanix Wear Team Issue Level 10 and Level 5 are both ARC Rated to be in excess of a 40 rating. Both models are proven to protect your hands from blast concussions, flame, fire and heat episodes from an arc flash. Here’s how: each Mechanix Wear glove features a specific number and layering of thermal insulative materials and arc tensile strength materials granting either glove its specific ARC Rating.

The beauty of the Level 5 and Level 10 are in the layering of the FR materials and the construction of various associated seams. By using as many as 3 layers of Carbon X and FR treated Leather, the flame and burn protection offered by the Level 10 and 5 is relative to the dexterity and protection required. Burns to the body and hands occur during the initial flash but can continue by being involved in a spray of molten metal drops and highly heated shrapnel released by the burst. The FR properties of the Carbon X protect your hands from flame and burn damage while the Kevlar threads used in the internally constructed seams hold the glove together during the shock/pressure phase of the burst thus not exposing your skin or body to further harm.