MDF is not the same as particle board.

Depending on your shop environment unpainted MDF can pick up mositure.

I live in SoCal & use MDF for all sorts of garage / shop cabinets, tool
racks & shelves. I pre-paint the sheets with an epoxy paint (esp the
edges). I second coat after assembly cutting & assembly

It accepts paint very well & with the epxoy paint the stuff is damn
near waterproof.

If you use LONG screws you can get away with going into edge grain.
The 5/8" sheet is pretty thin though. Otherwise use hinges that allow
face grain screws. The door is going to be a little on the heavy side,
use some good sized hinges.

cheers
Bob