Depends on the height - above 2.25m it'll be outsize zones so no particular requirements apply (just the general ones about being suitable for the environment). If it is in zone 1 then it needs to be at least IPX4 (or IPX5 if exposed to water jets for cleaning etc) and be suitable for that zone according to the manufacturer's instructions - which may or may not result in the manufacturer selling it as a "shower" version. If it was a little to the side and in zone 2 then IPX4 (or IPX5) would do even if the manufacturer didn't say anything about suitability.
In england work that is alteration an addition outside Zone 2 that is not a new circuit counts as non-notifiable under part P- which I assume is wnat you meant. In Wales it is notifiable, though who is checking if the work is notified or not I do not know.
