Have you ever swam in a lake long after dark when the moon is out and there’s this gorgeous glow to the water? There’s fog all around, making everything feel so much more mysterious and beautiful (and, if you’re me,Â terrifying). Well, that is a great thing! But not when it is created by liquid nitrogen, which can go horribly awry, as it did at aÂ JĂ¤germeister pool party in Mexico recently.
Apparently, the party’s organizers felt it was a good idea to pour large buckets of liquid nitrogen — a substance used to remove warts from people’s skin, a substance that should only be used in foods prepared by trained professionals — in a pool full of swimming people. It did not make for the fun, frisky,Â Wild Things-esque atmosphere I presume was intended. No, the stunt actually led to the guestsÂ asphyxiating and falling unconscious.Â sent Eight people were sent to the hospital;Â one of them is in a coma.
Chemist Paul Bracher explainsÂ better than I possibly could:
Molecular nitrogen is relatively inert and should not react with anything present in the pool, like â€śchlorineâ€ť (mostly, NaOCl) or water. The danger of adding liquid nitrogen to the pool stems simply from the nitrogenâ€™s boiling and pushing away all of the oxygen around, leaving none for the swimmers to breathe. The cloud that is present has nothing to do with poison gas. Rather, it is the same thing as fog. The liquid nitrogen is cold and cools the air close to the pool to the point that water vapor in the air condenses into very tiny droplets that stay suspended. The cloud is fog, generated from the same effect responsible for your being able to â€śsee your breathâ€ť when you exhale on a cold day. The visible cloud is not nitrogen and it is not smoke; it is droplets of water suspended in an atmosphere of air that is heavily enriched in nitrogen.
So again, let’s just review the lesson here: do not swim in liquid nitrogen. If you are at a party and alcohol reps pour liquid nitrogen into a pool you are swimming in or debating swimming in, get out and get away. They’re not your real friends. They probably don’t even go here.