fire extinguisher


You can make dry ice with a fire extinguisher

Inside many fire extinguishers is liquid carbon dioxide under high pressure. When it is released it rapidly expands into a gas. In doing so, it causes a rapid temperature drop due to ‘adiabatic cooling’.

If the gas is confined in a bag, the cold temperature freezes the carbon dioxide, creating a snow-like substance called dry ice.

Watch how this experiment relates to the third law of thermodynamics.

Be careful! Dry ice is very cold and can cause damage instantly to exposed skin. This should only be tried with suitable safety gear and experienced supervision.


The man with the microphone stood at the front of the big room.
“Okay,” the microphone man said. “Let’s do some icebreakers! Look at the person to your left and tell them something interesting about yourself!”
Bob looked to his left and saw a fire extinguisher. He looked around and everyone was already talking to someone else, so he talked to the fire extinguisher.
“Um,” said Bob. “Ya know that laugh track on TV shows?”
The fire extinguisher knew.
“Well, I’m one of those laughs. A few years back I saw an ad in the paper. ‘Do you like laughing?’ I do, so I checked it out. A bunch of us went into a big room with a bunch of sound equipment and we laughed for a few hours. They gave us lunch, but we had to laugh while eating it. You know how hard it is to laugh while eating hot soup?”
The fire extinguisher knew.
“Anyway, that’s kinda my claim to fame. Maybe even after I’m dead, my laugh will still be heard. And you’re a fire extinguisher. That’s cool. You save lives!”
The fire extinguisher hung on the wall in a way that make it seem like it noted that by saving human lives it killed fire lives and a life is a life.
Bob laughed and some hot soup came out of his mouth.
“Okay,” said the microphone man. “Now let’s do the same thing with the person on your right!”
Bob looked to his right and saw the same fire extinguisher.