"You get a rest break every four hours," the seasoned warehouseman told me back in the 1970's. He knew everything. I just assumed he was right about this, too. But, since then, I have never seen anything in law or regulation stating that workers were entitled to a 15 minute break every 4 hours. But, there is a regulation encouraging employers to provide a rest break every so often. 29 C.F.R. Sec. 785.18 tells employers that rest breaks improve efficiency. The regulation states that rest breaks of 5 to 20 minutes are common in industry. Any such rest break must be compensated. But, no rest break is required.
The regulations do provide that if a meal break is provided, it must be free of work duties. See 29 C.F.R. Sec. 785.19. Federal regulations do not require meal breaks. See Department of Labor's Questions and Answers about the Fair Labor Standards Act.