It may vary from region-to-region, but in Central States, the contract guarantees insiders only eight hours between their regular shift + helping. So if you're in a facility in which your regular shift exceeds eight hours, the company doesn't have to utilize you as a helper. But it depends on your coordinator... I had some that strictly enforced the rule, some that would try to keep you with as few hours as possible (in other words, if you worked an 8-hour shift, they'd assign you to the a route with the fewest hours) and others that simply didn't care unless you exceeded 12 (now 13) hours (at that point, you get flagged on a print out).