My cities Fire/EMS guys have had this in place for awhile I think. The LEO's are still catching up but there was some news a couple years ago about a local PD being the first in the area (PD not fire) to enforcement zero tolerance for smoking on or off duty. They do test and it can result in a suspension.
Im torn on this. Sure we need to be in the best shape possible. And I would never dream of smoking in uniform or on duty, but say I go to a bar to celebrate my promotion or something. When I drink I like to have a smoke. If I were in that local PD, I could get fired for that. Not sure exactly the Fire agencies around here and their specific policies, but I know your not allowed to do it. The Sheriff Dept. I do SAR for has no policies except no smoking while in Uniform (on duty or off, wearing your uniform, you cant smoke)
But good for them.