The union will win in Illinois.
When I was a IBEW union steward for Local 22 out of Chicago this issue came up right before I started working for Ameritech/SBC which is now AT&T (should of stayed there, I would be at Chicago wage scale but working in lower cost of living Rock Island--around $28 an hour plus commissions and bonus) We were the largest land line telephone provider in the United States.
Anyways this gay manager was standing outside of the woman's restroom with a stop watch timing how long pregnant women were away from their desks while they were urinating as they became closer to needing their six weeks off. We worked ten hour shifts and the breaks were spread out. This faggot knew nothing about the pain that women were going through just being there, sitting at there desks, all the time and once in a while they needed to simply take off their headsets and stretch for ten seconds. They were good employees. His boyfriend would drop him off at the front door and they would kiss, this was 1997...yeah did not see much of that then. His boyfriend was hired by the company and went right to one of the best jobs in the place as well.
IOSH (Illinois OSHA which now is pretty much fully combined with the IL Dept of Labor) came in and actually seen this faggot doing this to the women. It was very embarrassing to them to walk out of the restroom to have him say "in that three minutes you could of taken two calls" we were an inbound call center. Sales and Customer Service. A lot of the programing for the phone lines was writing code, rather then a windows based mouse click. If people would call and get mouthy and they wanted their phone service disconnected sometimes it would happen while we were still talking, I was their last call.
Due to this guy's harassment of the women that really had to piss.........and sometimes when I would go four hours between a break I occasionally had to go myself, but would try not to as I liked to be the sales leader...IOSH issued a $1000 fine towards the company, not a huge amount of money but really pissed off his boss, and they were required to post the state rules.
Restroom and hydration breaks are allowed as needed. As IL has no rules on breaks, nor are they mandatory, only a 20 minute lunch breach is if you plan on working a 7 1/2 hour shift, they are required to give you at least a 20 minute lunch within 5 hours of your start time. Most of us started the day drinking a lot of coffee, and sometimes you just need to drain the lizard.
Yeah I was a "union guy" but if any place deserved to have a union, it was these assholes.