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This paper includes an update on testing to characterize electric arcs and the performance of flame resistant clothing, first reported on at the 1996 Petroleum Chemical Industry Conference. The goal of this work is to assist electrical personnel in selecting appropriate arc protective clothing and equipment based on readily available electrical system parameters and the task to be performed.Updated protective clothing guidelines and detailed testing results on cotton ignitability and para and meta-aramid protective clothing systems are included. Results of additional three phase arc testing at 600 volts, including accoustical measurements, are discussed, as well as results of separate testing performed on polycarbonate face shields/hoods and leather work gloves.

Since 1982 when Ralph Lee wrote about "The Other Electrical Hazard: Electric Arc Blast Burns" [l], industrial and utility engineers have been attempting to better quantify the degree of risk to personnel associated with electric arc exposure and the appropriate protactive clothing to wear to mitigate serious injury. Recent activity by OSHA, NFPA 70E and ASTM F-18 has further emphasized the need to protect workers from arc flash burn injuries. This paper discusses the results of recent multiphase arc testing which has enhanced knowledge about: 1) potential arc energy as a function of prospective fault current, and 2) arc protective clothing designs that are suitable for different levels of incident arc energy. Incident energy levels are correlated with second degree burn criteria for unprotected human skin. Protective clothing systems consisting of flame resistant outer layers in singlelayer and multiple-layer construction, as well as combination systems of jlame resistant outer layers with natural and man-made fiber inner layers are discussed Protection recommendations for the face, head, hands and feet are also includedRegulations in OSHA 1910 Subpart R require that employees wear appropriate clothing when they may be exposed to an electric arc hazard. To meet these regulations, employees must not wear clothing that could increase the extent of injury that would be sustained by the employee in the event of electric arc exposure. Clothing made from acetate, nylon, polyester or rayon, either alone or in blends, is prohibited by OSHA 1910.269 unless the employer can demonstrate that the fabric has been treated to withstand the conditions that may be encountered, or that the clothing is worn in a manner that eliminates the hazard. OSHA has issued supplementary guidance for untreated cotton and wool, c l m n g the need for employers to determine that these materials would not ignite in potential arc exposure situations.The most recent edition of NFPA 70E, "Standard for Electrical Safety Requirements for Employee Workplaces,"[5] was completed at the request of OSHA and was issued by NFPA on February 7, 1995. Part 11, Chapter 3 covers personal protective equipment and requires for body ISBN: 0-7803-3587-2 96-CH35988-6/96/0000-028 1 $05.00 @ 1996 IEEE

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