If you were asking me, then no. The on call thing is pretty new to our company so I just needed some guidance to show them what they can and cannot do. As it stands, I had our union reps call the on duty manager, and they all agreed I shouldn't take the assignment until they were sure about the interpretation. But since my first post, I have found some good things that clearly state that being on call is not considered rest. Someone else posted it above as well... 135 On Call Rest Interpretation

Guess I'll have to go double check, but I'm fairly sure they can give us reduced rest and a 16 hour duty day if need be, but not sure if there's an exception for being on call. It's very rarely an issue, except for a few of the outstations that regularly work a little over 14 hours a day at least 3 days a week...