12 hours of work a day is inappropriate.
I did that for years, its so they can run two shifts, had lots of days off though. I worked 14 on 7 off, then 8 on 6 off. Some are 7 on 7 off. 12 hr shift though. They are also paid extremely well. All meals are paid for etc.
What they don't get is a "normal life ", lots of marital breakdows, spousal abuse when they do get home, parters cheating etc.