Why are most science students aware of the gas helium? It is probably because this compressed gas is used to make balloons float high into the sky.
Suppose you have a birthday or graduation party coming up. In that case, you might often find yourself wondering whether helium can catch fire; if yes, is it safe to use for a party?
A horrific video that surfaced online captured balloons exploding and catching fire in Karachi at a local school’s sports ceremony. This further reinforced the question, is helium flammable?
No, helium is not flammable. Helium is an inert gas which simply means it is non-combustible and non-reactive even when combined with other reactive gas!
But what about the helium balloons catching fire and exploding in Karachi at that sporting event? Read on as this post provides a better explanation for all the questions that plague you!
What is Helium?
Helium is simply a chemical element with atomic number 2 and symbol (He). After hydrogen, helium is the 2nd most copious element.
It is an odorless, colorless, tasteless, inert, non-toxic, monatomic gas – and is the number one in the noble gas group in the periodic table. The boiling and melting point of helium are the lowest among all the other 118 elements in the universe.
At low temperatures, helium turns to a liquid and becomes insanely handy as a coolant.
Is Helium Flammable?
Helium is not a flammable gas. Certain terms are used to describe helium gas, such as inert, non-reactive, and non-combustible, reinforcing its non-flammable nature.
From the periodic table, helium is categorized as a noble gas – this means that it certainly doesn’t burn in oxygen and won’t react with anything.
You can go ahead and heat helium in extremely reactive gases like fluorine, halogen, or cesium, or the most reactive alkali metal. Still, you won’t get a single reaction out of the gas.
You might wonder, why is this? Helium has all the electrons it needs in its outer shell, and it won’t give one up, nor will it take one from anything else.
Helium is such a stable non-reactive gas that is used as a cooling agent in rocket engines, used in-car airbags and welding, and, as you know, popularly used in filling balloons.
Since we have established helium’s non-flammable and non-combustible nature, a follow-up question will be on the incident of helium balloons exploding and catching fire.
What About the Incident of The Helium Balloons Catching Fire?
First and foremost, we want to correct the misnomer of helium and fire in the same sentence! You might counter this statement with, what of the horrific video of balloons exploding in Karachi at a sporting event?
This incident injured several school children who suffered from burns and scalds and were taken to nearby hospitals.
After this incident, several other video surfaces where birthday candles and sparklers caused explosions when coming into contact with balloons.
On deeper investigation, it was discovered that the balloons that exploded were not filled with helium but rather with either hydrogen or acetylene.
This is probably because helium is a tad expensive and difficult to obtain, unlike hydrogen, which is cheaper readily available depending on the geography.
Thus, if a balloon is filled with hydrogen or acetylene, a highly reactive gas manufactured with ethylene, it follows that a little contact with heat will lead to a massive explosion.
For instance, in this particular incident, the balloons simply brushing up against a light bulb caused the explosion.
As an unsuspecting buying, you can easily take home a balloon filled with hydrogen thinking it is filled with helium since hydrogen is even lighter than helium and gives the balloon its floating property.
Thus, there is a need for laws like the California Balloon Law, which strictly provides guidelines on the manufacturing, sale, and use of balloons.
Why Is Helium Gas So Often Mistaken as Flammable?
The Karachi incident has probably reinforced in the mind of plenty of people that helium is flammable. However, we have already established that the balloon was filled with hydrogen, a highly reactive gas.
Apart from that incident, when people hear of helium gas, they assume it is flammable since they associate gas with fuel or petrol.
Well, from this post, you know it is practically and technically impossible for helium to catch fire since it is a noble and inert gas.
Where Does Helium Come from?
For non-science students, they might wonder where does this gas come from? It is a very valid question. A memory trip to high school will reveal that helium is the second most abundant element in the universe – but quite limited on earth.
Helium is created under the earth’s surface from naturally occurring, decaying radioactive materials. These decaying radioactive materials give off helium which mostly rises into the atmosphere and is gone forever.
Sometimes, this gas is trapped in natural gas deposits which can be removed. However, this tricky and expensive operation explains why helium is expensive and hard to come by.
Know you know, helium can’t be termed a flammable gas because of its inert and non-reactive nature.
Thus, when buying balloons, you need to make further inquiries to ascertain that the balloon is filled with helium and not hydrogen or even acetylene which are highly reactive and explosive gases!
Remember that we mentioned that helium is quite a rare and expensive gas to come by.
Thus, you need to make sure that your birthday balloon is filled with the right gas and not the dangerous one that can easily explode when it comes in contact with a slight heat.