When I worked in Europe I was hired with about 260 hours TT. The difference is that the schools there train you to be an airline pilot from day #1. There is no wasting time on becoming a CFI or that sort of thing.

Also, the screening and selection process is vastly deeper and more thorough over there.

But go to Europe and fly on any major carrier - BA, AF, LH, LX, etc and you will fly with pilots who started their career flying Boeings and Airbusses with between 200 and 300 hours. It can be done and it can be done safely.

But the screening and training must be there to support that lack of experience.

To a certain degree, experience can be overridden with good training. The guy on the left seat over there does have plenty of experience. So it is just the guy on the right seat who is really low time.

Anyway, there is no magic number of hours needed to make someone safe. But less experienced pilots have to perhaps be screened a bit more thoroughly than someone with more experience.

But there are plenty of more experienced pilots who also have no business flying around in jets.