Welcome to brain Stuff production of I Heart Radio. Hey brain Stuff, I'm Lauren boge Bomb, and today's episode is another classic from our archives. This one is a bit of practical everyday science. Lots of spray canisters carry instructions to shake before use, but not compressed air canisters, and it's actually dangerous to do. So I'll let former Lauren
explain why. Hi brain Stuff, Lauren bulge Bomb here. Whether it's dry shampoo or paint, or accustomed to shaking aerosol canisters before we spray them, so it's only natural that when we pick up a canister of compressed air to clean a keyboard, we also want to shake the can even if it's label clearly says do not shake. But is this force of habit potentially harmful? In a word, yeah,
Compressed air canisters are not really canned air. Rather, these canisters contain a compressed liquefied gas that propels its own vapors through a nozzle. Most of the time, the liquefied gas is one of two types. One is di fluoro ethane or HFC one two A, which is found in canisters marketed for computers and electronic equipment, and incidentally, is also known as free on, that same gas that helps
make refrigerators and car air conditioners cool. The other type of gas is tetrafluoro ethane or HFC one thirty four A, which is recommended for use when flammability might be an issue, such as with hot surfaces or spark producing equipment. However, some types of can there may also contain butane, the
same liquefied gas found in cigarette lighters. According to three M, which manufactures and cells compressed air canisters for dust removal, shaking or tilting the can may result in propelled liquid instead of vapor. If this happens, the liquid may come into contact with skinner eyes and cause frost bite because the chemical will freeze your skin at room temperature. If
this happens, medical attention may be warranted. But first three M recommends washing affected areas of skinless soap and water, or flushing eyes with copious amounts of water. But what about all those other airsol canisters that do recommend shaking
before use. Unlike the liquefied gas and canned air that propels itself out through the nozzle, everything from dry shampoo to spray paint requires a little mixing, the product inside the can separates into layers and must be shaken to mix with the propellant before use, otherwise only the propellant would come out. Today's episode is based on the article why compressed air canisters shouldn't be shaken on how stuff
works dot com, written by laure L da. Brain Stuff is production of I Heart Radio in partnership with how stuff works dot Com, and it's produced by Tyler Clang. Or more podcasts from my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.