# Why do chemists use Nitrogen in their safety boxes? **URL:** \ **Category:** Factual Questions\ **Created:** [April 25, 2012, 3:35pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914 "2012-04-25T15:35:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 25, 2012, 3:35pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/1 "2012-04-25T15:35:31Z")
I’ve been watching the [Periodic Videos](http://www.periodicvideos.com) and in their safety boxes they use Nitrogen when they need an inert atmosphere. I’ve noticed this with other chemistry videos and TV programs too. I’m wondering why they don’t use a truly inert gas - one of the noble gasses? Nitrogen is not unreactive, so surely it’s a poor choice? Helium’s too expensive, but what about Neon or Argon? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 25, 2012, 3:42pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/2 "2012-04-25T15:42:40Z")
noble gases are really expensive and not available in high volume. oxygen is very reactive and could create a dangerous reaction or a reaction that would ruin the experiment or process being done. as long as nitrogen won’t cause a problem it is easy to get and inexpensive. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [April 25, 2012, 3:43pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/3 "2012-04-25T15:43:13Z")
Nitrogen is way cheaper (as it is _much_ more abundant in the atmosphere) than any true inert gas. For most purposes it is plenty inert enough. The main issue, usually, is simply going to be making sure things do not catch fire. ---
**Author:** ![cjepson](https://avatars.discourse-cdn.com/v4/letter/c/a9adbd/32.png) [@cjepson](https://boards.straightdope.com/u/cjepson)\ **Post date:** [April 25, 2012, 4:35pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/4 "2012-04-25T16:35:08Z")
> [@Quartz](#): > > I’ve been watching the [Periodic Videos](http://www.periodicvideos.com) and in their safety boxes they use Nitrogen when they need an inert atmosphere. I’ve noticed this with other chemistry videos and TV programs too. I’m wondering why they don’t use a truly inert gas - one of the noble gasses? Nitrogen is not unreactive, so surely it’s a poor choice? Helium’s too expensive, but what about Neon or Argon? Nitrogen gas is composed of molecular nitrogen (N2), which is pretty inert, due to the triple bond between the two atoms. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [April 25, 2012, 5:00pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/5 "2012-04-25T17:00:36Z")
> [@cjepson](#): > > Nitrogen gas is composed of molecular nitrogen (N2), which is pretty inert, due to the triple bond between the two atoms. Indeed. In fact, the reason so many explosives have nitro- in them is because they release a lot of energy as they react, because the end product, N2, is so very stable and low energy. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [April 25, 2012, 5:06pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/6 "2012-04-25T17:06:40Z")
It’s already been said that nitrogen is a LOT cheaper than noble gas. It’s also effectively inert, provided it is DRY. Moist nitrogen has a disappointing tendency to react with things. Usually you’re using nitrogen to keep things from oxidizing (bursting into flame being the extreme example of this) or you want to keep moisture off them (this is mainly what I used it for) Xenon costs over 200 times as much as nitrogen on a per-weight basis. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 25, 2012, 5:09pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/7 "2012-04-25T17:09:47Z")
> [@](#): > > Xenon costs over 200 times as much as nitrogen on a per-weight basis. That’s not really relevant, though, since what you really care about is the price of the _cheapest_ noble gas. How does the price of argon compare? ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [April 25, 2012, 5:19pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/8 "2012-04-25T17:19:34Z")
> [@Chronos](#): > > That’s not really relevant, though, since what you really care about is the price of the _cheapest_ noble gas. How does the price of argon compare? Also, since you are talking about using it to provide an inert atmosphere, shouldn’t you be more interested in comparing the prices on a per-volume basis? which is how gases are usually sold anyway. I’m sure nitrogen is still way cheaper. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [April 25, 2012, 5:25pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/9 "2012-04-25T17:25:18Z")
I looked it up quick, and they give the gas prices by mass, rather than volume. Xenon was the first one I chose, but my recollection was that there wasn’t a huge difference in prioce betwen argon and xenon. Checking, I find that on a per-weight basis, argon is only about 20% more expensive than nitrogen. ---
**Author:** ![Baracus](https://avatars.discourse-cdn.com/v4/letter/b/2bfe46/32.png) [@Baracus](https://boards.straightdope.com/u/Baracus)\ **Post date:** [April 25, 2012, 5:30pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/10 "2012-04-25T17:30:39Z")
> [@CalMeacham](#): > > I looked it up quick, and they give the gas prices by mass, rather than volume. Xenon was the first one I chose, but my recollection was that there wasn’t a huge difference in prioce betwen argon and xenon. Checking, I find that on a per-weight basis, argon is only about 20% more expensive than nitrogen. That is about what I found at a local supplier for research grade argon and nitrogen. For industrial grade gas or liquid, argon was about 3 times more. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [April 25, 2012, 5:40pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/11 "2012-04-25T17:40:17Z")
To convert to per-volume, argon is about 50% denser in gaseous state. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [April 25, 2012, 5:46pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/12 "2012-04-25T17:46:49Z")
For what it’s worth, wiki says that noble gases are used instead of nitrogen as the [shielding gas](http://en.wikipedia.org/wiki/Shielding_gas) in MIG and TIG welding. So for some purposes nitrogen doesn’t cut it. I’m guessing it’s because the heat makes the nitrogen gas more likely to ionize, making it more reactive. ---
**Author:** ![Cliffy](https://avatars.discourse-cdn.com/v4/letter/c/59ef9b/32.png) [@Cliffy](https://boards.straightdope.com/u/Cliffy)\ **Post date:** [April 25, 2012, 7:00pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/13 "2012-04-25T19:00:49Z")
> [@CalMeacham](#): > > I find that on a per-weight basis, argon is only about 20% more expensive than nitrogen. Although presumably that’s a function of demand being much lower, only for those (few-ish, I assume) applications for which nitrogen doesn’t suffice. So if every chemist in the world decided to switch from N to Ar, the price of argon would multiply dramatically. That is, nitrogen is still notably cheaper than argon despite an intense demand for nitrogen and a moderate demand for argon. –Cliffy ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 25, 2012, 8:24pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/14 "2012-04-25T20:24:18Z")
> [@Cliffy](#): > > Although presumably that’s a function of demand being much lower, only for those (few-ish, I assume) applications for which nitrogen doesn’t suffice. So if every chemist in the world decided to switch from N to Ar, the price of argon would multiply dramatically. That is, nitrogen is still notably cheaper than argon despite an intense demand for nitrogen and a moderate demand for argon. ICBW but isn’t liquid argon a byproduct of producing liquid nitrogen? I rather think that the volume of nitrogen used in chemists’ gloveboxes (which I’ve remembered as the correct term) is vanishingly small compared with all the other uses of nitrogen, though I can’t back that up with a cite. So a significant increase in demand might not result in a significant increase in price ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [April 25, 2012, 8:28pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/15 "2012-04-25T20:28:00Z")
Most chemists don’t use argon because nitrogen works just as well for a much lower cost. While in grad school we had five gloveboxes. Four had N[sub]2[/sub] atmospheres and one had Ar. My current lab is all nitrogen. Most chemists who require an inert atmosphere will never work with something that reacts with dinitrogen. If they do, it’s probably lithium metal. There are some metal complexes that will coordinate dinitrogen weakly, and even fewer that will coordinate it strongly or activate it toward some sort of reaction. Unless you really need to use it, money not spent on argon is better spent elsewhere. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [April 25, 2012, 9:32pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/16 "2012-04-25T21:32:46Z")
> [@Cliffy](#): > > Although presumably that’s a function of demand being much lower, only for those (few-ish, I assume) applications for which nitrogen doesn’t suffice. So if every chemist in the world decided to switch from N to Ar, the price of argon would multiply dramatically. That is, nitrogen is still notably cheaper than argon despite an intense demand for nitrogen and a moderate demand for argon. > > –Cliffy Isn’t argon used to fill incandescent light bulbs? I should have thought that was a fairly significant source of demand, certainly more than that of chem labs for nitrogen. (The principal demand for nitrogen is for making fertilizer, I presume.) I take it that the main source for both argon and nitrogen is distillation of liquid air, and the main relevant point for this thread is that that is going to net you hugely greater quantities of nitrogen. Furthermore, so long as the oxygen (and, probably, the CO2, and any reactive pollutants) has been removed, it is not going to matter much, for pretty much any application, if your nitrogen is contaminated with a bit of argon or other inert gas. By contrast, for most applications of argon, it probably will matter quite a bit if it is contaminated with nitrogen. That is another factor that is likely to make argon even more expensive. ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [April 25, 2012, 10:13pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/17 "2012-04-25T22:13:47Z")
I’ve read procedures that specifically call for an argon atmosphere because it will react with nitrogen, but that’s pretty rare. The last use for argon I know of in my part of the lab was for a pretty touchy organometallic catalyzed reaction. Sorry, don’t remember the name off the top of my head. Most organic chemistry, especially a lot of reactions done on scale, doesn’t really need an absolutely inert environment. Another factor is that nitrogen is simple to generate. A lot of places will buy liquid nitrogen and use the boil-off for their house nitrogen, but a decent-sized nitrogen generator will do for a small place. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [April 25, 2012, 10:54pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/18 "2012-04-25T22:54:37Z")
I used argon on my schlenk line because it is heavier. That gives you a little bit more leeway for sensitive reactions because it forms a blanket over any chemistry. My glovebox was nitrogen. There was one group doing nitrogen sensitive chemistry, and they used argon. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [April 25, 2012, 11:30pm UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/19 "2012-04-25T23:30:38Z")
> [@Smeghead](#): > > Indeed. In fact, the reason so many explosives have nitro- in them is because they release a lot of energy as they react, because the end product, N2, is so very stable and low energy. Like [Derek Lowe](http://pipeline.corante.com/archives/things_i_wont_work_with/) might say, nitrogen really _really REALLY_ wants to be a gas. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [April 26, 2012, 1:01am UTC](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914/20 "2012-04-26T01:01:02Z")
Compressed nitrogen is quite cheap. I do think welding supply companies stock it, so it may have welding uses too. When I worked in the paint industry, the plant mostly used burned air, mostly N2, CO2, and H2O. In the lab, a cylinder of liquid CO2 would work as an inert blanket for oxygen sensitive reactions for a long time. When we were working with isocyanates, we had to switch to what was called High, Dry Nitrogen. I am not sure where ‘‘high’’ came from. At one time we were using CO2 to pressurize a pressure pot paint sprayer. Oops! The CO2 dissolved into the lacquer increasing its volume and making a big mess. A switch to N2 solved that problem. The gas cylinders were a convenient source of high pressure that were in stock. [Next page](https://boards.straightdope.com/t/why-do-chemists-use-nitrogen-in-their-safety-boxes/619914.md?page=2)