The intense energy and very short duration of an electric arc flash represents a very unique exposure. Everyday work clothes made from regular cotton or poly/cotton fabrics, regardless of weight, can be readily ignited at some exposure level and will continue to burn adding to the extent of injury sustained from the arc alone. In addition ASTM F1506 (Standard Performance Specification for Textile Materials for Wearing Apparel for Use by Electrical Workers Exposed to Momentary Arc and Related Thermal Hazards) was developed to give minimum performance specifications for protective clothing. The major requirement of this specification was that the fabric is flame resistant, determined by using the standard vertical flame test.
Introduced in 1994, OSHA 29 CFR 1910.269 Electrical Power Generation, Transmission and Distribution required that clothing or garments worn by employees could not contribute to severity of a injury. By utilizing flame resistant garments utilities can comply with OSHA requirements and avoid potentially more serious burn injuries from garment ignition. Fabrics and garments which meet the requirements of ASTM F1506 are in compliance with the standard.
Proposed changes to OSHA 29 CFR 1910.269 are going further though in requiring that employees now be wearing flame resistant clothing.
