Don't try this at Home...or in a Laboratory

There are many obvious dangers associated with working in a laboratory. For example, in a microbiology lab there is the risk of being infected with a hideous disease, in a histology lab there is the risk of losing fingers while using a microtome, in a physics lab (say the Large Hadron Collider) there is the risk of creating a black hole, in a chemistry lab there is the risk of poisoning from horribly toxic chemicals. All good fun. But a particularly sinister - and hidden - danger, and one that is common to most laboratories, is the presence of a gas cylinder, and the potential for the gas cylinder to "torpedo" if the regulator (pressure gauge) is knocked off. [I'm using the term "gas" to mean a substance in its gaseous phase, eg a gas cylinder containing nitrogen].

The theory is that if the regulator (which covers the opening of the steel cylinder) is suddenly removed from a full gas cylinder - eg if the cylinder falls over and the regulator gets knocked off during the fall - the gas, which had been under pressure, will be expelled, with great force, away from the cylinder. Due to Newton's third law of motion*, the cylinder will also be "expelled" - away from the gas - with the same amount of force, resulting in an out-of-control airbourne steel cylinder, capable of destroying most, if not all, of a laboratory, and the scientists contained within.

As someone who has worked in chemical laboratories, and has been a little sceptical about the "gas cylinder torpedo" theory, I was pleased (and a little freaked) to discover that those crazy funsters from Mythbusters have tested - and confirmed (this is what freaked me) - this theory. [The video I've embedded is a cutdown to show the actual torpedo; I haven't seen the whole episode so I don't know if they tried anything other that complete shearing of the regulator on a full cylinder; for example I don't know if they tried just loosening the regulator and/or using a partially full cylinder.]




*Newton's Third Law of Motion : To every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.