Nitrogen is one of the most common elements in the galaxy and it’s the biggest component of the Earth’s atmosphere. In fact, with every breath you take more than three-quarters of each lungful is nitrogen. But should we be concerned about this? Is it possible that nitrogen is flammable? And what about liquid nitrogen?
Nitrogen is not flammable. It has a very strong, triple bond that is stable and causes very low reactivity. It will not catch fire in most cases.
However, there are important safety considerations with these substances, here’s what you need to know.
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Also read: What Makes Something Flammable?
What Is Nitrogen?
Nitrogen is a gas at room temperature, and it is both colorless and odorless.
It is a diatomic gas which means that two Nitrogen atoms bond together to form one Nitrogen gas molecule (N2).
Approximately, 78% of the planet’s atmosphere consists of Nitrogen and it is, by far, the most abundant raw element (e.g. not in compound form) on the Earth.
Our bodies use nitrogen, as do the bodies of all living creatures, and you will find it in our DNA and RNA as well as in ATP (which is Adenosine Triphosphate which helps to transport energy around the body).
Nitrogen is so important to life on Earth that we have the “nitrogen cycle” which is a full description of how the element moves from the atmosphere, into the biosphere, into the organisms that live in that biosphere, and then back into the atmosphere.
Also read: Is Hydrogen Flammable? Explosions…
What Is It Used For?
Nitrogen is used in many different industrial processes, and it’s used to make ammonia, nitric acid, nitrates (which are often used as explosives as well as for propellants), cyanide, etc.
Reducing nitrogen compounds to release the nitrogen in them often results in the release of large amounts of energy which can be very useful in manufacturing and industrial processes.
Nitrogen compounds can also cause pollution and are responsible for what’s known as “eutrophication” (the addition of too many nutrients to water causing algae to bloom and destroy the usual organisms in the water) of watercourses.
This is usually due to agricultural or industrial runoff into the water.
You can also find nitrogen compounds in use for such diverse things as antibiotics and Kevlar, wherever you look, nitrogen probably plays an important role in it.
What Is Liquid Nitrogen?
Liquid nitrogen can be created either by cooling nitrogen down to very low temperatures (-196 degrees Celsius or -320.8 degrees Fahrenheit) or by pressurizing it intensely at room temperatures.
In most cases, for convenience, the liquid nitrogen people encounter is pressurized at about a 1:694 expansion ratio.
It is worth noting that if the liquid nitrogen is released from pressure, it assumes a very low temperature which can cause problems.
What Is Liquid Nitrogen Used For?
Liquid nitrogen has many uses but primarily it is used in medicine and cryogenics as well as, occasionally in the bar industry.
Is Nitrogen Flammable?
Under normal circumstances, nitrogen will not ignite and it is neither considered flammable, nor combustible.
This is good news given the prevalence of nitrogen in the atmosphere, if it could catch fire every time that someone lit a match, the Earth would never stop burning.
Thankfully, for all of us, nitrogen isn’t flammable. If it was, life would probably be nothing like we experience it to be, today.
Is It Explosive?
Nitrogen is not explosive but it is worth noting that if it is stored in gas canisters, and the canisters are heated – the nitrogen will expand and cause the canister to explode if it expands enough.
From a user’s perspective, at this point, it won’t seem like nitrogen is not explosive.
This means that it’s important to keep nitrogen cylinders in a safe place and isolated from potential sources of heat and/or flame.
Can Nitrogen Gas Ever Catch Fire?
Nitrogen won’t burn under any normal circumstance (it is possible to create conditions that nitrogen can burn under – that’s how they make nitrous oxide, laughing gas but they won’t occur in the wild).
This is due to the fact that nitrogen is a terrible thermal conductor and that the strength of the Nitrogen triple bond in N2 is higher than in any other gas except for the bond between carbon and oxygen in carbon dioxide.
Can It Spontaneously Combust?
No. Nitrogen does not spontaneously combust, it has a hard enough time burning in the first place, it won’t start burning with no effort.
Is Liquid Nitrogen Flammable?
No. Liquid nitrogen is not flammable, neither pressure nor a reduction in temperature makes nitrogen any more flammable.
Take a look at this in action:
However, as liquid nitrogen is pressurized in canisters, there is an explosion risk of the canisters are heated appreciably as the liquid nitrogen can expand and destroy the canister.
How Dangerous Is Nitrogen?
Nitrogen is not dangerous under normal circumstances.
After all, we’re constantly breathing it in and out and it’s found throughout our bodies.
However, it is possible to be suffocated using nitrogen if you raise the nitrogen level in the air enough to push out the oxygen.
So, if you work with nitrogen gas, it’s important to work in a well-ventilated area to prevent this from happening.
Can Nitrogen Be Destroyed?
Nitrogen cannot be destroyed, you can see how this works in the nitrogen cycle but as per the law of conservation of matter, nitrogen cannot be created or destroyed in chemical processes like burning.
Can Liquid Nitrogen Put Out A Fire?
Yes. In fact, ordinary nitrogen could, in theory, put out a fire as it would be possible to spray it on fire to cut off the source of oxygen and as nitrogen does not burn, this extinguishes the fire.
However, it’s quite difficult to use gas to smother a fire and it’s much easier to do it with a liquid and it’s easy to see that liquid nitrogen extinguishes more fire per unit of nitrogen used on the fire.
Is Liquid Nitrogen Hazardous?
Liquid nitrogen is very hazardous and, in fact, even though it’s used in the bar industry to make exciting cocktails with vapor coming off of it – this practice has caused serious injury in drinkers.
This is because liquid nitrogen is so cold that it rapidly freezes any tissue that it comes into contact with along with any bodily fluids.
Even the briefest of touches can result in bad burns, frostbite, and permanent damage to tissue or eyes.
How Can It Kill You?
Prolonged exposure to liquid nitrogen would result in fatal cold burns, in the same way, that being exposed to a fire for long periods of time would result in fatal heat burns.
Liquid nitrogen can also kill by evaporating, without causing anyone harm. and then displacing the air in the room which leads to headaches, dizziness, passing out and then death by asphyxiation.
In short, liquid nitrogen is not a good thing to mess around with.
What Does Skin Look Like After Liquid Nitrogen Burns?
Liquid nitrogen is used in cosmetic and other forms of surgery to burn things off the human body and these burns are not serious.
When the use of liquid nitrogen is carefully controlled, it results in minor burns that can form a scab or blister which eventually falls off by itself.
Uncontrolled nitrogen burns can be very serious and if you burn yourself with liquid nitrogen you should consult a physician immediately.
Can You Drink Or Eat Liquid Nitrogen?
Under no circumstances should you eat or drink liquid nitrogen. In the best-case scenario, this would leave you with serious internal injuries, in the worst case, it would result in your death.
We’d strongly recommend that you do not consume cocktails made with liquid nitrogen as a mistake by the bartender can result in serious injury for you.
Is It OK To Put Liquid Nitrogen Down A Sink?
No. Liquid nitrogen should never be dumped down a sink. The cold of the nitrogen liquid can cause severe damage to pipes, etc.
The best way to get rid of liquid nitrogen is to allow it to evaporate outdoors or in a very well-ventilated space.
Do You Need A License To Buy Liquid Nitrogen?
Strangely, despite the dangers of liquid nitrogen, you do not need a license to buy it. You do, however, have to show ID when purchasing it and provide a good reason to buy it.