In the years I was learning about drafting we were still using vellum and making blue prints which were a type of photo reactive paper that you would place your finished drawing and expose to light and then cure in a cylinder full of high potency ammonia solution. The problem with that was that there were thirteen and fourteen-year-old’s fooling around with chemicals that could kill us all. The first couple of times were were curing the prints the teacher did it all himself and then he turned it over to us which is where it went wrong. One afternoon when the teacher was actually out of the class someone spilled the whole gallon of the toxic curing brew. It was instantly suffocating and the students left in the room fled the scene and ran into the hall where the fumes were still spreading. There was only two other classes on that hall – art and technology and in about ten seconds they had gotten wind of the issue and were running outside and the teacher was still not back. There were about a hundred kids choking and coughing standing out on the back patio in the cold with only one teacher trying to sort us all out. The fire department came and sealed off the that classroom and started ventilating. In the calculus of young adulthood a little burning of the soft tissues of the lungs was a small price to pay for a little time on the more or less loose. We didn't have to go back to class for the rest of the day as we were moved around outside until we were taken home on our regular buses. Awesome day, most especially if you happen to like the smell of ammonia and the burn of it in the old breathe bags.