Why Having A Liquid Nitrogen Pool Party Is A Bad Idea

[n2doc]

Note to Fox News: it wasn't a cloud of toxic chlorine.
By Francie Diep


So you probably know it's not a good idea to swim in a pool with liquid nitrogen. You might not know exactly why—we'll discuss this further ahead—but it just sounds like a bad idea, right?

Right. German liquor company Jägermeister recently hosted a party in Mexico, during which staffers poured what appeared to be numerous 10-liter dewars of liquid nitrogen into the water, creating a foggy effect. In videos, you can hear partiers "Woo!"-ing… and then, not two minutes later, those not in the water pointing and saying, in Spanish, "Somebody's fainted. Someone else has fainted." Another video shows partiers jumping into the pool to pull limp bodies out of the water.

What happened? Not what others have reported, according to ChemBark, a blog by St. Louis University chemist Paul Bracher. Fox News Latino, the U.K.'s the Daily Mail, KTLA and others have said the nitrogen reacted with chlorine in the pool to form a "toxic cloud."

"This is almost certainly incorrect," Bracher wrote. Actually, molecular nitrogen is inert and shouldn't react with anything in the pool, he said. Instead, the nitrogen displaced oxygen from the air above the pool, "leaving none for the swimmers to breathe." Yipes!

more
http://www.popsci.com/science/article/2013-06/why-having-liquid-nitrogen-pool-party-bad-idea

There is no "almost certainly" about it. N2 is essentially inert unless very high energies are applied to it, or certain catalysts (biological or otherwise).

[Buzz Clik]

1. Hm. About breathing nitrogen:

These guys breathe nitrogen:




These do not:

[DreamGypsy]

5. Well, actually, Jack Nicholson, et al, do breathe nitrogen...with every breath...

...since the Earth's atmosphere is ~78% nitrogen. However, our lungs only absorb the oxygen, and only a small part of the oxygen, ~20% of the atmosphere, on each breath. The nitrogen acts as an inert gas.

However, some animals inhale other bad things.

[SCantiGOP]

15. correct on being inert

That is why potato chip bags are filled so fully with nitrogen. Unlike regular air, that would ruin the chips in a few days, the nitrogen cannot react with the organic matter so it stays fresh.

[Downwinder]

2. 1954 -- New Mexico Military institute

On May 31, 1954 between 9 and 9:30 p.m., tragedy struck during Final Ball. Three cadets, Donald Wallace Vertress, Wood Mullinax Moore and Perry George Vlahopoulas, were assisting with decorations for Final Ball in the Luna Natatorium when a pump used to spray water malfunctioned. The three decided to prime the pump and in doing so went into the swimming pool where carbon dioxide was given off by dry ice on a platform under a decorative bridge across the pool. The noxious gas given off by the dry ice suffocated or asphyxiated the cadets. The announcement was made to a stunned and grief torn crowd about 10:30 that evening, turning one of the NMMI's finest galas into one of its greatest tragedies.

[longship]

3. Hold my beer. WATCH THIS!!

Darwin Award coming right up.

Anyway, they should have used liquid helium. It's crazy stuff.

[DetlefK]

8. LHe? That stuff is lethal. It can freeze you, asphyxiate you and explode, all at once.

There are reasons for laboratory safety briefings. If you don't watch out, if you don't know what you are doing, if you don't keep a clear head
That.
Stuff.
Can.
Kill.
You.

[longship]

10. Uhm! No! It cannot explode.

Helium is an inert gas and does not interact with anything.

I've worked with it; it's weird stuff, but relatively safe. (For stuff that's at about 3 degrees above absolute zero.)

[DetlefK]

11. I'm not talking about combustion. I'm talking thermal expansion.

Even the tiniest amounts of energy are enough to bring it to boil and it has a far greater volume as gas than as liquid. If that much heat sneaks in while the liquid Helium is in a closed vessel, the pressure will rise until the vessel explodes (if some idiot forgot to open the safety valve), sending shrapnel flying, pushing oxygen out and freezing the vicinity so cold, you get skin-damage.


I've worked with it, too, occasionally refilling the LHe-cryostat of a low-temperature STM.

[formercia]

19. Helium will suffocate you just as fast.

Fail.

[Warpy]

4. Dumb dumb dumb dumb dumb

The same intensity of lethal fog could have been had for a lot less money with a few hundred pounds of dry ice.

If you want to kill off your guests, why waste money on liquid nitrogen?

(something tells me a "molecular gastronomist" was catering this disaster)

[JayhawkSD]

6. Dry ice would do the same thing

Carbon dioxide would also displace the oxygen and suffocate the swimmers.

[rwsanders]

16. The big difference is that CO2

would trigger the bodies defenses and they would know something is wrong. If the O2 is displaced, they would never feel short of breath.
There were a few USCG inspectors (and others) entering enclosed spaces that died because rusting actually consumed the O2 and left air that wouldn't support life, but didn't provoke the feeling SOB.

[TxDemChem]

7. 2 posters hit the nail on the head

We breathe air that is approximately 78% N2 and 21% O2. Our bodies metabolize the O2 for various processes required to biologically function. The size of a diatomic oxygen molecule is very similar to that of diatomic nitrogen and carbon monoxide; therefore, in the presence of extreme concentrations of N2 or CO, the O2 is displaced and we essentially are suffocated. You will get lightheaded and possibly faint, or worse, die.

Figured I'd also add that diatomic nitrogen has a triple covalent bond, so it is pretty inert; it would take some work to break those bonds. I seriously doubt the nitrogen reacted with much of the chlorine to form any sort of hazardous product.

[eppur_se_muova]

12. It certainly did not react. N2 is called an "inert gas" in industry.

Find an easy way to get N2 to react, patent it, and you could become the richest person in history.


ETA: cf n2doc's "no 'almost certainly'" remark in the OP. With a name like n2doc, I suppose he could be an expert on N2.

[TxDemChem]

14. I know!

My main concern was with the impurities that may be present in the canister they got the liquid nitrogen from, not so mich the N2 itself. I'm guessing they may have gotten 99.9% or even 99.99% purity. And if they allowed any air into the tank when they opened it. No telling what environment they opened it in and what the pressure of the canister was before opening. Either way, you're right. Under everyday conditions, the N2 won't react.

[formercia]

20. N2 will react.

An experiment in Basic Chemistry is to burn some Magnesium in Air, leaving a white powder. One would assume it is Magnesium Oxide, but if you add a few drops of Water, the odor of Ammonia soon be comes apparent. The Magnesium burns at a high temperature which, Besides the Magnesium Oxide, forms Magnesium Nitride, which will react with water to form Ammonia.

[eppur_se_muova]

21. Yes, yes ... with magnesium, with lithium. Not with anything found in a pool at room temp.

Actually, lots of reactive metals react with nitrogen, but they are all a bit "exotic" and usually produced only by electrolysis. Not a practical approach to N2 fixation.

Thermodynamically, the reaction of N2 and O2 is exothermic, but the barrier of activation is absurdly high. IC engines produce traces of NOx this way, but only traces.

[mercuryblues]

9. I sense

a CSI Vegas plot in the making.

[eppur_se_muova]

13. Well, DUH ... http://en.wikipedia.org/wiki/Inert_gas_asphyxiation

Accidental deaths[edit]

Accidental nitrogen asphyxiation is a possible hazard where large quantities of nitrogen are used.

Accidental nitrogen asphyxiation causes about eight deaths per year in the United States,[12] which is asserted to be more than from any other industrial gas. For example in 1981, shortly before the launch of the first Space Shuttle mission, two technicians lost consciousness and one of them died after they entered the Orbiter aft compartment which was pressurized with pure nitrogen as a precaution against fire.[13]

A laboratory assistant died in Scotland in 1999, apparently from asphyxiation, after liquid nitrogen spilled in a basement storage room.[14]

Occasional deaths are reported from recreational death from inhaling helium, but these are very rare from direct inhalation from small balloons. Entering large helium balloons has been fatal.[15] Accidental falls have been fatal after a person inhaled from a balloon, and lost consciousness. Lung rupture and fatal gas embolism has occurred from inhaling from a pressure tank, and although this is reported as helium inhalation death, it is a different process from inert gas asphyxiation.[16].



http://en.wikipedia.org/wiki/Inert_gas_asphyxiation

http://www.csb.gov/board-releases-safety-bulletin-on-nitrogen-asphyxiation-hazards-underscores-need-for-good-safety-practices/



In this case, the N2 was cold, thus denser than warmer air, and so accumulated in the pool instead of escaping.

[Iterate]

17. 1986: 1700 dead at Lake Lyos, Cameroon

In that case the initial reports also blamed toxic gases, largely because those who survived the gas escape from the volcanic lake were on slightly higher ground and were only exposed to the lighter, irritating gases such as hydrogen sulfide. The real killer was the heavier CO2 that flowed close to the ground.

In 2011, a woman was killed in a McDonald's restroom in Georgia from CO2 that had leaked from a soda machine.

CO2 is also used to kill chickens before slaughter. There is some controversy over the use of CO2 in fire suppression systems because of its lethal and narcotic effects on those trying to escape a fire.

As with the N2 in this incident, it is referred to as "inert gas asphyxiation" even though CO2 is not technically inert. In either case there is no struggle and no warning.

The promoters who pulled this stunt might barely be excused for not knowing about inert gas asphyxiation, but certainly not the reporters who should at least have been aware of past events and some high school chemistry.

[intaglio]

18. unsurprisingly this has made it to the "Cool" classification

on the front page.

Obvious really -195 degrees C