Does ABS come in a CLEAR UL recognized Flame Retardant grade suitable for electrical use?
Does it have to be ABS?
What thickness is your wall and do you require a specific V rating? (V0?)
I believe Lexan is V0 at 3mm in clear. You may want to give Sabic a call and they can help you out.
I think UL V0 and about 2 - 2.5 mm thick ABS in clear.
I was thinking PC+ABS blend too but want to go cheap yet acceptable so I was thinking simply ABS FR UL V0.
I don’t know if you’ll find a clear material at that thickness/rating.
Try giving some of the plastics vendors a call - they’ll get you on the right path much quicker I think.
I think Lexan is your best bet. Any time I’ve done work in airports I’ve had to use lexan anywhere I would use acrylic or other plastics due to flash points.