We all know that there are some gases you don’t want to expose to open flames. But what about helium? There are a couple of reasons why I felt it was important to look at the questions of whether helium is flammable, explosive, or both.
Helium is not flammable and it is generally safe to use in many situations. Helium is an inert gas which is non-reactive, allowing for some unique uses from balloons and blimps to other industries with dangerous materials and high heat.
However, we do know that balloons and blimps can explode. So, let’s look more at why helium is so safe and what is really going on in those situations.
Is Helium Combustible?
Helium is not a combustible gas, which means that it is safe to use in a lot of applications. It is a popular choice in many industries because it retains this non-reactive trait at various temperatures.
It isn’t going to ignite at high temperatures, although there are other safety considerations depending on its use. It is also possible to cool helium to the point where it becomes a stable liquid.
Even then it won’t pose a fire risk, which is why it is possible to use this liquid as a cooling agent around rocket engines.
While there are some great benefits in using liquid helium as a cooling agent, this isn’t something to mess around with.
It is stable enough not to pose a fire risk, but it is still incredibly cold and needs to be handled with care. Contact with the liquid could lead to skin irritation in minor cases.
Prolonged exposure could result in frostbite.
Is Helium Gas Toxic?
While helium isn’t toxic in the same way as some other gases, you still don’t want to breathe it in.
This may come as a surprise when you see so many people inhaling helium from a balloon to get a squeaky voice. A little bit of helium will produce this comical effect and then wear off.
However, too much helium can be dangerous as it displaces vital oxygen. Excessive helium could displace enough oxygen from your lungs and bloodstream to cause lightheadedness and breathing problems.
Inhaling pure helium straight from a tank can lead to asphyxiation or a fatal embolism. Because of this, it is advisable not to let children get into the habit of inhaling from helium balloons.
You don’t want them to take things too far when they are older.
I wrote an entire article on whether oxygen can actually explode. Click the link to check it out.
Is Helium Explosive?
The reason we ask about the explosive nature of helium is because of those situations with popping helium balloons and the Hindenburg disaster.
I’ll get onto why the Hindenburg was a completely different situation in a moment.
As for popping helium balloons, this is down to other factors and not any kind of explosive or combustible property in the gas.
Why Do Helium Balloons Pop?
Many of us have been in a situation where we’ve given a child a big helium balloon, only for them to accidentally let go and watch it drift away.
Eventually, these balloons will explode high up in the air and the remains will drift back down to earth – or often into our oceans.
This pop is not down to any explosive element in the helium, but rather the pressure on the balloon. There is a big difference in air pressure at ground level compared to high altitudes and this can react with the pocket of helium within the balloon.
Eventually, this will become so intense that the thin balloon can’t take it anymore and will burst.
Are Helium Balloons Safe To Have Indoors?
Yes. There are incidents where helium balloons can burst at ground level. This tends to be when they are exposed to high heat and the temperatures cause the air inside to expand too much.
You might see this happen outdoors in really hot weather, but it can also happen with concentrated sunlight through a window.
Be careful where you display any helium party balloon on hotter days.
If they do burst, they can cause a bit of a fright but they aren’t going to do any damage, leak any dangerous gas, or cause a fire risk.
On this note, you should also be careful when transporting and storing any canisters of helium gas for parties and other occasions.
They could overheat in the back of a car or in extreme sunlight at home and experience similar pressure issues to the balloons. This isn’t a fire risk, but you still don’t want to be near an exploding canister.
Why Did The Hindenburg Explode?
So, now we know just how safe helium balloons are, we need to look at the Hindenburg disaster. If you are unfamiliar with this event, the summary is as follows.
In 1937 a giant German airship carrying passengers over New Jersey exploded and crashed to the ground, killing 36 people.
It was an enormous aircraft that the Nazis were very proud of but, due to US export bans, used hydrogen rather than helium to inflate it. T
his was a fatal mistake as hydrogen is incredibly flammable and reactive compared to the safer helium.
Because of this high flammability rating, it wouldn’t have taken much to ignite the gas and put the craft and its passengers at risk.
The official starting point of the fire onboard the Hindenburg was a “discharge of atmospheric electricity” next to a gas leak.
The spark was enough to ignite the hydrogen and before long the whole airship went up in flames.
Miraculously, not everyone on board died.
Are Helium Blimps Safe?
Yes, helium blimps and airships are a lot safer because you don’t have the same fire risk.
A spark or a small fire onboard isn’t going to ignite the gas and you would have a much better chance of putting out any flames and keeping the ship airborne.
A helium blimp for advertising or other promotional work might theoretically pop like a balloon if it were to get too hot or too high in the atmosphere.
But, a small-scale blimp over an airshow or football game isn’t going to hurt. The biggest threat would be it coming untethered and putting aircraft at risk.
Why Don’t You See Helium Blimps Anymore?
Another reason you might assume that helium blimps and hydrogen blimps are the same – or at least as dangerous as each other – is that you rarely see blimps anymore.
The main reason for this is their cost. They are an impractical option because of the gas and materials involved.
A small advertising blimp isn’t going to be cheap, especially when you can hire someone with a small plane and a banner.
It would be even more costly to try and create something that could carry passengers. There is also that consideration of air traffic safety in areas with busy flight paths.
Other Uses Of Helium Gas
I want to end by talking more about the safety of helium gas to emphasize how stable and interesting this gas is. Helium is one of the few truly inert gases that are part of the noble group in the periodic table.
Inert means that they are non-reactive and are a great choice for a wide range of applications. Of course, this doesn’t mean that all inert gases are 100% safe, as there are issues with radon leaks in houses. But, many are used in a variety of ways in various industries.
Helium is a good example of that because you can find it in applications from arc welding to leak detection systems. It is even in barcode scanners!
Perhaps the most interesting use of helium, and one that really highlights its safety, is its use in airbags.
When you are in a car accident, you want that airbag to inflate as quickly as possible to offer the best possible protection.
Well, it turns out that helium is the ideal choice because of its rapid action. On top of that, you need something that isn’t going to react with any sparks, high heat, or flames that result from the accident.
If the car starts on fire, you don’t want to be resting on a cushion that could explode.
How Safe Is Helium?
To summarize, helium is a lot safer than you might imagine because of misconceptions about helium balloons. Helium is neither combustible nor explosive, even though a balloon can burst under the right conditions.
Hydrogen is a far more volatile gas, and this is the reason for the Hindenburg airship disaster.
While we don’t see helium blimps so much anymore, that doesn’t mean that helium isn’t a major part of our lives. In fact, it could help save your life in a car crash.