We have completed a study of AR short sleeved shirts worn UNDER Rubber insulating sleeves for three utilities which have requested this to be published and made available to OSHA.
The digest of the study is that we could not see energy getting far enough down a sleeve to burn skin from the back (even with the sleeve holders disconnected) if the sleeves on the t-shirt were at least 10 inches 25 cm long.
The sleeves tested were black rubber and used carbon black as the colorant and these did not ignite in any exposure which was as high as 40 cal/cm². The arc flash used was the ASTM F2621 Test Method Guide using the same arc as the ASTM F1959 standard with a 12 inch open arc and 3000 volts. With an AR short sleeved shirt and the sleeve keepers in place, there is relatively NO chance of second degree burn until the rubber sleeve ignites. If the rubber sleeve ignited (we know of no instances of this in T&D work), the AR shirt, short or long sleeved would still be unlikely be able to prevent burns.
Utilities and other companies must do their own hazard assessment but ArcWear feels this a comprehensive study to evaluate this potential hazard on power line work.