Protective clothing guidelines for electric arc exposure

Since 1982, when R. Lee wrote (see ibid., vol.IA-18, p.246), industrial and utility engineers have been attempting to better quantify the degree of risk to personnel associated with electric arc exposure and the appropriate protective clothing to wear to mitigate serious injury. 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 multiphase arc testing which has enhanced knowledge about potential arc energy as a function of prospective fault current and 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 single-layer and multiple-layer construction, as well as combination systems of flame-resistant outer layers with natural and man-made fiber inner layers are discussed. Protection recommendations for the face, head, hands, and feet are also included.