It has not dipped below four hours since. And of course, the four hour average hides great disparities in overtime. Many of our members routinely work double shifts and more. I know another who went more than 100 days without a day off. In fact, more and more companies are unilaterally imposing mandatory 12-hour shifts.
Safety is one concern.
Of course, fatigue increases the risk of accidents. And overtime may be more fatiguing than in the past. A decade ago, a maintenance worker working the night turn as the second half of a double shift, might have spent most of his or her time simply on call. Today, that worker is much more likely to be on the floor, fixing a piece of equipment. That may be a more efficient way to operate, but it certainly increases fatigue.