Someone posted "Does it have to be electrical material to be a sleeve." Or something like that. Well IMHO if you just use it for a sleeve, then NO! It doesn't have to be UL listed or labeled for electrical work. After all you can use a piece of wood to support, or protect a piece of wire and that is not UL labeled for electrical work. NOW if you were installing THHN wires in a water pipe, should that pass inspection? I don't think so. However a great big piece of 4" Plumbers pipe under a driveway and the EC slips a piece of UF through it, what's that harm? We need to use a little common sense when we inspect these jobs. ( I would hope!)
