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Saf-T-Gard catalog

ARC FLASH 101 Most fatalities and serious injuries in electrical work, almost 80% by some counts, occur when there is an electrical contact. Protection from shock should be the first consideration in injury prevention but another serious hazard is electric arc. One study presented to ASSE (American Society of Safety Engineers) indicated that 80% of all electrical injuries occur from arc flash and the possible ignition of flammable clothing in electrical arc events. Whether the arc is initiated by dust or corrosion, the dropping of an un-insulated tool, human error or the failure of equipment, the first line of defense all workers should have for arc protection should be flame-resistant clothing with an arc rating. 190ELECTRICAL SAFETY • ARC FLASH 101 Arc flash protection is paramount for use in industrial markets such as oil and gas, water and wastewater, metals and mining, petroleum refining, and chemical processing. It is also ideal for use in utility markets covering electrical co-ops, electrical contractors, electricians and power and communication linesmen to name a few. What is Electric Arc? Basically it is the ionization of air, the instantaneous vaporization of the electrode material (usually copper or aluminum) and the resultant heat blast and shock wave. Most of the energy in an electric arc is thermal but the shock wave component increases with higher fault currents and other factors such as the shape of the piece of equipment and the location of the worker. Electric shock and arcs have been linked to as many as 2,000 hospital burn unit visits annually in the United States, so the prevention of and the protection from these events is critical. Most of the victims of serious arc ashes are industrial workers and maintenance personnel. What do I need to do about it? OSHA has required companies to mitigate the eects of “arc ash” since 1991 but had little guidance for the average industry. Now, most regions of OSHA are now enforcing parts of NFPA 70E under the general duty clause, and on February 14, 2007 OSHA indicated their intent to include it in full in future legislation as they mandated Part One of the 2000 version which included chapters 1-2. NFPA 70E has long been an OSHA recommendation but until 2000 it was a sidelined standard. is was the year that the standard became more than a compilation of NEC (National Electrical Code) language and became a standard in its own right. Now it is the second fastest selling NFPA standard second only to the NEC. What are flame-resistant materials? »» Treated Natural Fibers Flame-resistant cottons, such as Indura® FR cotton, fall under this category. Another less common material is ame-resistant wool which might be used in a winter jacket. »» Treated Blends In the past 5-7 years, new engineered blends have been introduced and now dominate the arc market. Westex’s Ultra So® and Salisbury® PRO-WEAR® are examples of cotton blends with high tenacity nylon. ey perform better in arc ash due to an ablation eect and other factors in electric arc response. e material also performs well in laundering and outlasts the FR cottons by about double. »» Inherent Materials like Nomex®, Kevlar®, CarbonX® and others are inherently ame-resistant. ey are almost always sold as blends, but the materials are ame-resistant without treatment because of the nature of the compounds from which they are made. It is not correct to call them synthetic, since most people think of synthetic as melting materials. ese materials do not melt and are excellent in ame resistance. ey also tend to be very durable (especially Nomex and Kevlar). ey are used most in the arc market in rain gear and in ash suits for their light weight.


Saf-T-Gard catalog
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