All the posts on this subject are accurate however the original one refers to "utility" which I assume to mean transmission and distribution (above 600 volts)work.
If I'm correct and your going use the requirements of NFPA 70E then you'll need to do the calculations and if you do... you'll find that the "FR" clothing typically issued to these workers doesn't even come close.
Work it de-energized or use hot sticks to stay beyond the required flash protection boundary.
I agree that "FR" clothing will help but it's PPE which should be the last line of defense.
