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Nyrin t1_j92f707 wrote

You know how salt has historically been used as a de-icer? That's because salt water has a lower freezing point than normal water, meaning it has to get colder to freeze.

When it gets cold enough anyway, salt water forms something with the cool name of a "eutectic frigorific mixture," which establishes crystals of high-heat-transfer ice crystals on skin at much, much lower temperatures than normal ice. That means really bad frostburn with no sensitivity to know you're even being burned.

This has apparently been idiotically embraced as an "internet challenge" enough to merit a Wikipedia page:

>The mixture of ice and salt create eutectic frigorific mixture which can get as cold as −18 °C (0 °F).[3]

>The salt and ice challenge can quickly cause second- and third-degree injuries similar to frostbite or being burnt with the metal end of a lighter, as well as causing painful open sores to form on the skin. Due to the numbing sensation of the cold and possible nerve damage during the stunt, participants are often unaware of the extent of any injuries sustained during the challenge, only feeling pain once the salt on their skin enters lesions created during the challenge. Skin discoloration from the challenge may remain after the challenge has been attempted.[4][5][6]


BrightCharlie t1_j93b1jl wrote

And in case you're wondering where the water comes from in rock salt, remember that sodium chloride is a powerful desiccant, it'll literally remove water from the air and turn it into salt water -- which is also why it's used as a food preservative, because it very thoroughly dries it (and any bacteria it might have, too)


[deleted] t1_j948dn7 wrote



DeftTurnOfPhrase t1_j94a0xa wrote

This basically does happen in places with high humidity. It doesn't become "full" of water, but the salt clumps together enough to become impossible to shake out of the container. One remedy is to mix the salt with dry rice, which is either more of a desiccant than salt or has a mechanical effect that breaks up the clumps.


lunchlady55 t1_j95wnw2 wrote

Not Morton Salt with it's anti-caking agent Calcium Silicate!

When it rains, it pours!


Y34rZer0 t1_j95zjtx wrote

just like glitter clumping, it’s a common stripper problem.
Well that’s what my Nan used to say


Kolemawny t1_j949toz wrote

There is a humidity difference between your kitchen and an underground mine.


freshmountainbreeze t1_j94yulb wrote

The top of the shaker is often covered with water droplets where I live due to the salt residue collecting moisture from the extremely humid air.


rational_american t1_j97epu7 wrote

Where would this be? That sounds like variations in temperature are causing condensation. I have lived on a literal island in the ocean, 500 meters from the pounding waves, and have had my salt clump a bit, but never dissolve itself into salt water in the container, even though dew and condensation was on everything at least some part of almost every day.


comparmentaliser t1_j95gl6h wrote

Many restaurants put rice in the shaker to help break up clumps that form when it a absorbs moisture.


akeean t1_j937lot wrote

You can use this effect to chill some cans of soda or beer very quickly. Put just enough cold tap water to submerge your cans+ice cube+salt in a bowl and slowly stir with a long spoon until the cubes *melt.Wait a minute & give the can a short wash under cold tapwater (to wash off the saltwater)

Edit: Non-native English speaker here. I used molten there since it is interchangable in German 'geschmolzen' as incorrect past tense of 'melt' for describing the phase change of a substance from solid to liquid. The German term works with glaciers, ice cubes, rock and steel. I see it makes no sense in English like this. Thanks for correcting me. Must be painful to browse reddit, lol.


LogicalMeerkat t1_j93k3dt wrote

Describing ice cubes as molten is weird and I don't like it. It's not wrong, it just sounds wrong.


[deleted] t1_j93p69z wrote



monsieurkaizer t1_j93pgtj wrote

It is because they can't be molten. Molten means liquefied by heat. Cheese can be molten, because it exists as cheese and melted cheese. Ice cubes just melt into water. So they're no longer cubes, and maybe that's why it irks you.


ParanoidMaron t1_j93q0ce wrote

>Molten means liquefied by heat.

... Ice melts thanks to heat.. into liquid water, ice is just solid water. Ergo, ice can become molten, as water and ice are the same material, just the same as aluminium is the same material molten or not.

It sounds wrong. It is not, technically speaking, wrong.


Reliv3 t1_j93s6hd wrote

Yeah, I think molten is actually fine here. People are just used to using molten when describing melting materials which are solid at higher temperatures. Ice is a solid at much lower temperatures, so a state one may describe as "molten" will also exist at a much lower temperature.


Patsastus t1_j946f5s wrote

It's more that "molten" is an extra descriptor used for the liquid state of something that's usually solid. So molten ice sounds fine, molten water sounds weird and tautological, because of the assumption that you mean liquid water the majority of the time you say "water"


Fish_On_again t1_j94lrgk wrote

Temperatures are relative. There are many places on this planet where water in its molten state is very rare at times.


[deleted] t1_j94dnn2 wrote

Molten is only really used with things that are hot and will solidify again at room temp.

For example there is molten chocolate and there is liquid chocolate(sauce). They have clear definitions and are straight up never used interchangeably. Its like a rectangle and square.


asdaaaaaaaa t1_j968s3c wrote

It's how you "make" ice cream at home. You use salt + ice to drop the temperature really cold, really fast.


mschweini t1_j93iz8i wrote

Since sweat is also salt water - do our bodies somehow do against this effect when sweating in cold climate?


EBtwopoint3 t1_j93tgsd wrote

The salt itself doesn’t make the water any colder. It just lets the water get colder before freezing, and increases the rate of heat transfer. For sweat, if it’s not much below freezing it’s really no different than being wet. With that said, sweating when it’s really cold out actually is dangerous.


DieFlavourMouse t1_j94sroa wrote

Thank you, there's a lot of great information I your response. "eutectic frigorific mixture" is quite a fascinating concept. But can you explain a bit more of what you meant by "... frostburn with no sensitivity to know you're even being burned"? Why do we sense this phenomenon differently than other types of burns?


InevitableSignUp t1_j9621ra wrote

I hate to sound silly, but where does the extra cold come from? Is this assuming the ice/salt mixture is still in a sub-freezing environment? How does putting salt on ice and then onto your skin make the ice colder? Colder enough to cause such damage?