There are smoke detectors in all of the science class rooms at my school, and there’s one teacher that fills the room with tobacco smoke (for educational purposes) for multiple classes once a year, and to my knowledge, the alarm has never gone off because of it.
Somebody told me that a couple of years ago, somebody tried cooking bacon inside of the school and that set the system off. :lol:
But as for popcorn, a long time ago, somebody burned popcorn really badly in the cafeteria (it was so bad you could smell it from the other side of the school), and the alarms did not go off.