Regs code for perished shrouds?

[Slewis120]

Hi, just undertaking an EICR on a factory and have came across, some perished shrouds inside of an old main frame board, i can not seem to find a regulation relating to this if there is one, also the boards have a wooden top panel where the cables enter before glanding off on the internal gland plates, is there a regulation for this also. Also came across these inside the board snd PFC’s.
Cheers

 

[westward10]

Those aren't shrouds it is conductor insulation almost certainly xlpe. Xlpe is generally resistant and the only things I can imagine have caused that is extreme over heating or chemical attack, the copper shows signs of corrosion so what sort of environment is it.