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  #1  
Old 08-17-2009, 09:34 PM
Deeg Deeg is offline
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Where can I buy liquid nitrogen in the Boston area?

I want to try making ice cream with liquid nitrogen.
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  #2  
Old 08-17-2009, 09:46 PM
GaryM GaryM is offline
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Try http://www.boc-gases.com/products_an...ogen/index.asp


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Supply options
Call Us or Email Us for advice on the most cost effective supply option to meet your needs, these include:

* Compressed nitrogen gas cylinders for convenience or for mobile supply. Cylinder sizes and pressures are tailored to local markets.
* Liquid nitrogen cylinders for small volume cryogenic applications.
* Bulk nitrogen delivered by cryogenic tankers into on-site storage for high-volume applications.
* On-site nitrogen generation for secure cost-effective supply, from low volume ultra-high purity nitrogen supply to electronics facilities to hundreds of tonnes a day for food freezing.
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  #3  
Old 08-18-2009, 11:23 AM
janeslogin janeslogin is offline
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Isn't it in the yellow pages under welding supplies?
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  #4  
Old 08-18-2009, 02:09 PM
Chronos Chronos is offline
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You can also often get it from universities, of which there are a few in the Boston area. Contact the physics or engineering departments.
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  #5  
Old 08-19-2009, 12:32 PM
Mama Zappa Mama Zappa is offline
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No clue where to get it but I wanted to pop in and say it's great fun at parties, freezing and smashing stuff. A physics grad student brought a dewar of it to a party I attended and many laughs were had by all.

Disclaimer: the stuff can injure if improperly handled so don't do this unless you know what you're doing. Maybe also not good to combine LN games with alcohol consumption, which I guess limits the types of parties at which such fun should be had.
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  #6  
Old 08-20-2009, 10:09 AM
kayaker kayaker is online now
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Quote:
Originally Posted by Mama Zappa View Post
A physics grad student brought a dewar of it to a party I attended and many laughs were had by all.
How does the OP hope to transport the nitrogen? IME, an (empty) dewar costs >$500.
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  #7  
Old 08-20-2009, 11:56 AM
Chronos Chronos is offline
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You only need a dewar for long-term storage. For the short term, an ordinary consumer thermos like the one you carry hot coffee in will work fine. The only caveat is that you have to file the threads off the cap so it doesn't close tightly-- Try to seal a thermos of liquid nitrogen, and you've got yourself a bomb.
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  #8  
Old 08-20-2009, 12:09 PM
muldoonthief muldoonthief is offline
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Quote:
Originally Posted by Chronos View Post
You can also often get it from universities, of which there are a few in the Boston area. Contact the physics or engineering departments.
Heck, wander around the basements of various MIT buildings, and you just may find a storage tank or two, complete with filling stations.

NW16. Info is 20 years old, use at your own risk
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  #9  
Old 08-20-2009, 12:18 PM
Deeg Deeg is offline
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Thanks for the responses. I'm still trying to get a hold of the gas distributor on MIT's campus. My thought (perhaps ignorant) was that I could rent the dewar from the distributor.
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  #10  
Old 08-20-2009, 12:32 PM
HorseloverFat HorseloverFat is offline
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>No clue where to get it but I wanted to pop in and say it's great fun at parties, freezing and smashing stuff.

Cool. What did you smash? Im guessing plants and food are safe. Was there a lot of cleanup afterwards? Im guessing the pieces fly everywhere.
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  #11  
Old 08-20-2009, 12:46 PM
Harmonious Discord Harmonious Discord is offline
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Just don't be like the German cook that blew off his hands. Article
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  #12  
Old 08-20-2009, 12:53 PM
Mama Zappa Mama Zappa is offline
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Quote:
Originally Posted by HorseloverFat View Post
>No clue where to get it but I wanted to pop in and say it's great fun at parties, freezing and smashing stuff.

Cool. What did you smash? Im guessing plants and food are safe. Was there a lot of cleanup afterwards? Im guessing the pieces fly everywhere.
Yeah - I seem to recall leaves, and a ketchup packet (the contents turn into pale orange powder). Plus whatever other things we gathered up from the party supplies. This was 20+ years back so I don't recall all the details but I'm pretty sure we swept up; it was in a basement room with concrete floor so not too messy, all in all.
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  #13  
Old 08-20-2009, 12:56 PM
HorseloverFat HorseloverFat is offline
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Any idea of how much you used? Id like to buy the safest amount possible.
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  #14  
Old 08-20-2009, 02:18 PM
Mama Zappa Mama Zappa is offline
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Quote:
Originally Posted by HorseloverFat View Post
Any idea of how much you used? Id like to buy the safest amount possible.
I doubt it was very much - probably less than a pint. It was brought in an open-top dewar (sort of like a Thermos on steroids) by a grad student whose lab was down the hall. The dewar was perhaps the size of a half-gallon milk container.

I wouldn't really recommend playing around with the stuff, unless you know what you're doing regarding handling the stuff safely. As the article from Harmonious Discord shows, and Chronos points out, the stuff *can* be dangerous if mishandled. At the very least, spill it on yourself and you'll get a nasty case of freezerburn (no joke - anywhere from a few blisters to more serious skin damage). Same caution goes for Deeg who wants it for culinary purposes.
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  #15  
Old 08-20-2009, 04:12 PM
Chronos Chronos is offline
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Quote:
At the very least, spill it on yourself and you'll get a nasty case of freezerburn (no joke - anywhere from a few blisters to more serious skin damage).
Not unless you have extended skin contact. You could dump a bucket of it over your head and it'd just spill harmlessly off of you. You can even plunge a hand into it, as long as you're quick about it.

Now, plunging your hand in and leaving it there for a few seconds, that's bad, but that's beyond the realm of "didn't take adequate precautions" and into "just plain stupid". The only real precaution you need to take beyond "don't be stupid" is to not seal the stuff up (that looks like the mistake that German chef made).
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  #16  
Old 08-20-2009, 04:43 PM
Deeg Deeg is offline
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I assume that one should be careful choosing the containers to use. For example, don't pour LN2 into a glass (or possibly ceramic bowl).
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  #17  
Old 08-20-2009, 05:07 PM
johnpost johnpost is online now
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i wouldn't consider it something to play with.

that said if you haven't used it before and know how to use it then i would think it stupid to not have eye protection for splashing fluids.
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  #18  
Old 08-20-2009, 05:40 PM
JR Brown JR Brown is offline
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Quote:
Originally Posted by Chronos View Post
Not unless you have extended skin contact. You could dump a bucket of it over your head and it'd just spill harmlessly off of you. You can even plunge a hand into it, as long as you're quick about it.
Don't believe him. We use LN2 to freeze cell lines and mouse bits for storage and before grinding tissue for RNA/protein extraction. Splashing the stuff on yourself will, at the very least, give you a whole new meaning of "burning cold".

Whatever you've got the stuff in, or freeze in it, be careful about touching/holding it for too long. The first thing that happens is your skin/fingers/whatever goes numb, so you don't notice the irreparable tissue damage....

Note that, for short-term manipulation, you can perfectly well put a small amount of LN2 in one of those foam ice buckets like they used to have in motels, or even a styrofoam cooler; it evaporates fairly quickly though. Watch out for splashes, and make sure you maintain appropriate ventilation.

Last edited by JR Brown; 08-20-2009 at 05:41 PM..
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  #19  
Old 08-20-2009, 07:26 PM
Chronos Chronos is offline
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Really? I've never been hurt when I've splashed it on myself. Was yours maybe maintained at below the boiling point?

The bit about glass or ceramic bowls is a good point, though: The thermal shock can crack them.
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  #20  
Old 08-20-2009, 08:17 PM
racer72 racer72 is online now
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I was given about a gallon if it once. It came in a very thick styrofoam cooler. Onions shatter like glass. Carrots spinter into shards. Frozen potato chips taste nasty. A can of Pepsi was ice cold after 5 seconds. Slugs, potato bugs, and bees do not come back to life, the ants that did not break moved when thawed but were not the same. And for the 420 friendly, flash frozen bud is hard to light and other than a odd taste, it doesn't help or hurt the buzz. An afterthought was a bong filled with liquid nitrogen. What would the smoke do when frozen?
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  #21  
Old 08-20-2009, 09:03 PM
johnpost johnpost is online now
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Quote:
Originally Posted by racer72 View Post
I was given about a gallon if it once. It came in a very thick styrofoam cooler. Onions shatter like glass. Carrots spinter into shards. Frozen potato chips taste nasty. A can of Pepsi was ice cold after 5 seconds. Slugs, potato bugs, and bees do not come back to life, the ants that did not break moved when thawed but were not the same. And for the 420 friendly, flash frozen bud is hard to light and other than a odd taste, it doesn't help or hurt the buzz. An afterthought was a bong filled with liquid nitrogen. What would the smoke do when frozen?
it is hazardous to place something in liquid nitrogen and touch to yourself or put in your mouth. that object could be well below the freezing point of water, it could cause instant cell death. this would include freezing food objects or cooling alcohol beverage. as mentioned before touching an uninsulated container at liquid nitrogen temperature will freeze cells.

things have to reach their combustion point temperature before burning. things don't burn when they are cold.

a bong of liquid nitrogen could be very hazardous. you would have a lung full of cold nitrogen gas. it could be so cold as to damage your lungs, nitrogen gas is an asphyxiation hazard at that concentration as well.
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  #22  
Old 08-21-2009, 08:55 AM
Quercus Quercus is offline
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Originally Posted by JR Brown View Post
..and make sure you maintain appropriate ventilation.
This is easy to overlook, even for someone smart enough to avoid frozen flesh. Nitrogen gas won't directly hurt you, but if you add a bunch of it to a room, it will displace oxygen. And a lack of oxygen will make you a little stupid, then make you pass out, then kill you dead. And note how the first effects can easily lead to a) not noticing them, and b) failing to take steps to remedy the problem.

If you're playing with it inside, make sure there are fans or other ventilation unless you're in a very big space.
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  #23  
Old 08-21-2009, 10:27 AM
Deeg Deeg is offline
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I found a distributor who will sell me some. Now I need to find someone to rent me a dewar.

Does anybody have an estimate at how long LN2 will last in an enclosed styrofoam bucket (like the ones used to hold ice in hotels)? If it will last 12 hours I might be able to get by with one of those.

Last edited by Deeg; 08-21-2009 at 10:28 AM..
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  #24  
Old 08-21-2009, 11:03 AM
johnpost johnpost is online now
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Quote:
Originally Posted by Deeg View Post
I found a distributor who will sell me some. Now I need to find someone to rent me a dewar.

Does anybody have an estimate at how long LN2 will last in an enclosed styrofoam bucket (like the ones used to hold ice in hotels)? If it will last 12 hours I might be able to get by with one of those.
it is very important to allow for pressure relief of the container. do not put into anything with a screw on top. the top must be able to come up (with the slightest flick of a finger) to relieve pressure, not necessarily come off.

you also want a container that is stable and will not tip or spill its contents easily and be insulated so you can touch it without being exposed to the cold.

i would read all the cautions people have given and take them to heart.

doing home made liquid nitrogen ice cream is a hazard. don't ingest it until it is at normal household food freezer temperature. ingesting it before then could cause frostbite and maybe cell death in mouth, tongue and throat and would happen instantly before you could sense it.
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  #25  
Old 08-21-2009, 01:35 PM
WarmNPrickly WarmNPrickly is offline
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Quote:
Originally Posted by JR Brown View Post
Don't believe him. We use LN2 to freeze cell lines and mouse bits for storage and before grinding tissue for RNA/protein extraction. Splashing the stuff on yourself will, at the very least, give you a whole new meaning of "burning cold". ...
A cell line doesn't have warm blood pumping through it. You can definitely stick your hand in liquid N2 and pull it out without harm. I've done it many times. I doubt that your liquid Nitrogen was much below boiling either. If it was, your hand will change that quickly.

I would be suprised if anyone would sell you liquid nitrogen into an unapproved container. Like Chronos says, it can explode if mishandled. Even beyond simple pressure expansion, it can condense liquid oxygen. Unlike liquid Nitrogen, liquid oxygen is quite dangerous and can detonate from contact with almost anything.
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  #26  
Old 08-21-2009, 02:20 PM
enigmatic enigmatic is offline
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I've used liquid nitrogen quite a bit. While it isn't as dangerous as most people usually think, it's certainly not "safe". Mostly going to reiterate what other people have said.

1) When evaporating the stuff will expand to about 700 times it's volume, therefore it doesn't take much to fill an average sized room if you spill the stuff. If this does occur in an enclosed and poorly ventilated space you have much less time than you think to get out. The stuff will displace the air in your lungs just as easily as the air in your room and you can go from fine to unconscious in seconds. Fortunately it will tend to fill a room up from the bottom rather than spreading evenly, but this can cause problems if someone bends down suddenly to pick something up.

2) As people have said, keeping it in a sealed container will cause an explosion, the better sealed and stronger the container, the bigger the eventual bang.

These two factors are by far the biggest risks associated with the stuff and also combine to make it hard to transport safely, spilling it is bad (especially in a car) but you can't transport it in a sealed container which increases the spillage risk!

As far as it's freezing effects go you can treat it exactly the same way that you would with a very hot liquid with a couple of specific caveats - Firstly it is easy for the stuff to spill on other objects and cool them to the point that they can burn you.

Secondly whilst the leidenfrost effect discussed up thread does provide a degree of safety in handling, it is a very dangerous thing to rely on. The effect is caused by instant evaporation of the nitrogen, forming a cushion of gas between the droplet and the surface it has spilled on. The problem is that the effect tends to disappear abruptly once a threshold temperature has been reached. So one minute the stuff might be spilling off your hand and cooling it slowly and the next second your hand gets too cold and you are suddenly sustaining serious injury.

Being splashed on your clothing can cause problems because the fabric will quickly cool to the critical point and then get cold very fast, this cold fabric will then quickly reduce the surface temperature of your skin to the point that injury would occur. Sadly the the false sense of security caused by this effect can often cause people to be much sloppier in handling it than they would otherwise or to mess around with it, whilst unaware of the degree of risk they are taking.

As I said earlier if you treat the same way you would a very hot liquid whilst being careful not to keep it in a sealed container or use it in a confined small space you should be pretty safe.
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  #27  
Old 09-08-2009, 11:33 PM
Deeg Deeg is offline
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An update just in case somebody finds this thread looking for LN2.

I was able to get a used dewar at Cambridge Scientific Products for a good price. I had to go to them, though--my phone calls were ignored. I was also lucky (I think) that they just happened to have a smallish dewar.

I found LN2 by looking up welding supplies. The best deals I found were at Spec Air Gases & Technology (the owner was very friendly) and Igo's Welding Supply. I was able to get LN2 for less than $1/liter. Definitely check around--apparently the price will swing wildly up or down depending on how much they have on hand. One place gave me a quote of $3/liter one week and $7/liter the next week.

We made ice cream and it was very good. It took a few iterations to get the process down but we ended up with very creamy ice cream. Frozen marshmallows were a big hit too. I grabbed the opportunity to sneak in a physics lesson for my two teenage nieces and their friends.

Thanks for the suggestions and the safety tips. I felt pretty confident that nothing would go wrong.
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  #28  
Old 09-09-2009, 03:03 AM
otorophile otorophile is offline
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quick question: is the reason for liquid nitrogen's relative safeness because of it's low thermal conductivity or because it forms an insulating layer of nitrogen gas around whatever it touches?
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  #29  
Old 09-09-2009, 07:05 AM
johnpost johnpost is online now
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Quote:
Originally Posted by otorophile View Post
quick question: is the reason for liquid nitrogen's relative safeness because of it's low thermal conductivity or because it forms an insulating layer of nitrogen gas around whatever it touches?
all depends on circumstance.

the thread has statements of handling, safety and potential hazards.
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  #30  
Old 09-10-2009, 11:10 AM
Napier Napier is offline
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Quote:
Originally Posted by JR Brown View Post
Don't believe him. We use LN2 to freeze cell lines and mouse bits for storage and before grinding tissue for RNA/protein extraction. Splashing the stuff on yourself will, at the very least, give you a whole new meaning of "burning cold"..
Chronos is right, in my experience. I have many times stuck my finger into a bowl of liquid nitrogen for several seconds, and poured and held a small handfull for a few seconds, and even taken a small mouthfull and then blown it out (to spectacular misty effect).

I'm sure that you can do yourself very nasty harm with LN2, and I consider the possibility of touching a solid object at LN2 temperatures as a very nasty threat (especially if the fingers are wet with water). But brief splashes and submersion of extremeties in the liquid does not seem to be a problem at all. It has only ever given me a whole new meaning of "how interesting, now let's try this...".
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  #31  
Old 09-10-2009, 05:00 PM
Stranger On A Train Stranger On A Train is offline
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Quote:
Originally Posted by Chronos View Post
The only real precaution you need to take beyond "don't be stupid"...
You're asking a lot of most of humanity in that regard.

Stranger
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  #32  
Old 09-22-2009, 10:47 PM
falk falk is offline
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Enigmatic has a lot of good advice.

I've been playing with it a lot for the last couple of months, mostly making ice cream and sorbetto.

Safety guides say wear gloves, but I'm not so sure that's a good idea. If the stuff soaks into or runs into your gloves, you'd be a lot worse off than if you just splashed it on your bare hand. Once while making ice cream, my girlfriend suddenly screamed and shucked her gloves as fast as she could. We were using our patented Dr. Horrible welding gloves, but they won't help you if the stuff runs inside.

I've seen someone dip their hand into LN2 and splash it at us with no ill effect. I also saw someone get frostbite trying to imitate that person, so beware.

A lung-full of pure nitrogen will suck the oxygen back out of your blood. In a pure N2 environment you can be unconscious in seconds. A couple of safety documents I've read claim that more than half of N2-related deaths were caused by people rushing in to try to help someone else. One poor sap was standing over a vat of LN2, got a lung-full of the stuff, and then pitched forward into it. He was not missed for several hours. Mull on that.

That said, as long as there's reasonable ventilation, and you don't actually spill the whole dewar on the ground, there's really nothing to worry about.
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  #33  
Old 09-22-2009, 10:48 PM
falk falk is offline
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Where can I get a dewar serviced?

Picked up a 30L dewar for nothing on Craig's list, but it's rusty on the inside. Anybody know where I might take such a thing to be inspected, cleaned, and have its vacuum replenished? I'm in Silicon Valley FWIW.
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