The only smoke machines that I've seen used dry ice and water....emitting strictly water vapor...was yours different???
The dry ice machines create that fog that sticks to the floor and flows almost like water. The kind I use suspends in the air for a nice affect when lighting is shooting through it.
In our case it makes a set of four LED panels look like a cool laser show. They use water and Glycol. Harmless unless you are subjected to prolonged and very dense concentrations (which doesn’t happen), and even then it’s harmless, but may cause mucus membrane irritation. i.e. it might make your eyes water.