Given how many ladders and walkways in Trek engine rooms have no rails and other protection for users I'd say OSHA was a victim of the Third World War and never reinstated.
One thing that's for sure is that Starfleet has a grandiose overconfidence in security features almost regardless of the exact application. From computer technology ('but this system is protected with extremely advanced recursive quantum encryption algorithms! Even with all of the Federation's computational power at your disposal, you'd need billions of centuries to .... oh, I see you got in') to engineering ('warp core breaches' we are told at its first occurrence in TNG should be extremely unlikely, yet we get to see it happen with some frequency afterwards.)