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. The need to protect against arc exposures has necessitated the development of new test procedures. 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.

OSHA Requirements  
   OSHA (Occupational Safety & Health Administration) in the United States has confirmed that garments which meet the requirements of ASTM F1506 are in compliance with OSHA 29 CFR 1910.269 Electrical Power Generation, Transmission and Distribution, with regard to garments not contributing to burn severity.
   To address the industry?s request to utilize non-flame resistant clothing based on an analysis of their exposure level, ASTM developed F1958, whereby non-flame resistant garments, which do not meet the requirements of ASTM F1506, are tested on a manikin to determine the probability of ignition. The employer would be required to supply a set of prescribed criteria detailing the potential exposure of each employee. To reliably determine ignition probability, numerous series of arc exposures must be run. The major problem associated with applying this test protocol is that accidents typically do not follow a prescribed set of rules and a burn injury enhanced by clothing ignition could be the result of deviations from unanticipated conditions. By utilizing flame resistant garments compliance to OSHA requirements can be assured and potentially more serious burn injuries from garment ignition may be avoided.