Probably the 91 hour per week limit the article mentioned, if they were clocking 12 to 14hr shifts they would meet or break that maximum hourly limit often. Those are insane work hours!
"Rest hours: rest hours should be implemented in national legislation. The maximum hours of work in that legislation should not exceed 14 hours in any 24-hour period and 72 hours in any seven-day period, or: at least ten hours of rest in any 24-hour period and 77 hours (rest) in any seven-day period. Furthermore, the daily hours of rest may not be divided into more than two periods and, at least six hours of rest should be given consecutively in one of those two periods."