We have that on most of the job sights I work at. Very limited outside smoking areas.
In some work areas it makes damn good sense. Refineries, and the like where one dipshit could blow us all to hell.
And I can also see it in offices where a lot of the air is recycled through the building. My mother (retired now) has always had really bad allergies, not just cigs but also heavy perfume wearers and the like. In her case she shouldn't have it inflicted on her.
But in my line of work most of our jobs are in paper-mills. Have you ever smelled a paper mill? If you've driven with in 10 miles of one, you've smelt one. We go into these things and we weld and cut steel that has been impregnated with these chemicals. You let your head get into the smoke it will knock the breath out of you, and if you're really careless you'll be coughing up blood. Sometimes you can use a resperator, most of the time you set up ventilation to keep the worst of it away. Anyway most of these are now non-smoking. A guy has a smoke plume so thick you cant see through it, maybe 14" in dia. going 10 ft in the air, and he gets written up because the cig hanging out his mouth is a health hazard.
Then you go into the brake room to rest. There’s maybe a dozen guys in there, I'm the only one who doesn't smoke, and I don't care. The safety guy comes in and writes someone up for it. In some towns a cop could come in and give the guy a ticket (never seen it happen but the laws there.)
Basically if nobody working their minds it should be a non-issue. If even 1 person has a complaint then there should be no smoking anywhere they have to be.
Personally, I'd rather deal with a little smoke in the air then 12 guys on a nicotine jones.