# Why does water put fire out? **URL:** \ **Category:** Factual Questions\ **Created:** [May 27, 2016, 12:38am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776 "2016-05-27T00:38:36Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![obbn](https://avatars.discourse-cdn.com/v4/letter/o/d6d6ee/32.png) [@obbn](https://boards.straightdope.com/u/obbn)\ **Post date:** [May 27, 2016, 12:38am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/1 "2016-05-27T00:38:36Z")
Hello Everyone, Why does water put out fire? Besides, it’s wet. What exactly happen? Does water cover the combustible material and for a bond between it and the fire? ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [May 27, 2016, 12:41am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/2 "2016-05-27T00:41:46Z")
There’s a couple of things going on, I believe. First, water cools the fuel to where fire is no longer possible. Second, the steam displaces the air and thus deprives the fire of oxygen. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 27, 2016, 12:59am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/3 "2016-05-27T00:59:27Z")
Mainly cooling. Of course with enough water it also blocks of the supply of oxygen. Burning substances that have their own supply of oxygen often aren’t extinguished by water, and burning aluminum can strip the oxygen out of water molecules to keep burning. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [May 27, 2016, 3:31am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/4 "2016-05-27T03:31:58Z")
[Fire Triangle](https://en.wikipedia.org/wiki/Fire_triangle). > [@](#): > > The fire triangles or combustion triangles are simple models for understanding the necessary ingredients for most fires. > > The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture, meaning that fire is actually an event rather than a thing. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle. For example, covering a fire with a fire blanket removes the oxygen part of the triangle and can extinguish a fire. ---
**Author:** ![bordelond](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bordelond/32/150_2.png) [@bordelond](https://boards.straightdope.com/u/bordelond)\ **Post date:** [May 27, 2016, 3:42am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/5 "2016-05-27T03:42:30Z")
Slight tangent: What elemental sodium does when placed in water … is that properly called “burning”? Or is that reaction better described in other terms? ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [May 27, 2016, 3:42am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/6 "2016-05-27T03:42:43Z")
So water removes the heat, so it’s too cool for fire. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [May 27, 2016, 3:44am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/7 "2016-05-27T03:44:54Z")
The heat of the fire evaporates the water into steam and that reaction removes enough energy from the fire that it can’t sustain itself. ---
**Author:** ![Raygun99](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@Raygun99](https://boards.straightdope.com/u/Raygun99)\ **Post date:** [May 27, 2016, 3:55am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/8 "2016-05-27T03:55:03Z")
> [@bordelond](#): > > Slight tangent: > > What elemental sodium does when placed in water … is that properly called “burning”? Or is that reaction better described in other terms? It’s an oxidation reaction, or combination with oxygen, which **is** what’s happening in a combustion reaction - but it’s also what’s happening with a rusty car, which lacks a bit in comparison with the idea of burning. The flame produced from sodium and water is actually the combustion of the released (and very hot) hydrogen from water with atmospheric oxygen. Meanwhile, you can burn sodium directly and it looks like [this](https://www.youtube.com/watch?v=8PJP4MKFCfY). I’d stick with calling it an oxidation reaction. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [May 27, 2016, 4:14am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/9 "2016-05-27T04:14:11Z")
Water has two actions. cools the fire and if enough water is used it can deprive the fire of oxygen. ---
**Author:** ![Richox](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@Richox](https://boards.straightdope.com/u/Richox)\ **Post date:** [May 27, 2016, 5:47am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/10 "2016-05-27T05:47:45Z")
A slightly more involved description. Generally solids don’t burn in the obvious way, they get hot enough to begin releasing vapours that do burn. If you lower the temperature of the burning item sufficiently, the vapor release stops, and therefore the fire does not continue. Hence some things can’t be controlled with water… Their vapor release point is lower than the possible cooling effect of water. For a heavily engaged fire, a sensible temperature for that to occur is 90ish deg C ---
**Author:** ![bardos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bardos/32/1069_2.png) [@bardos](https://boards.straightdope.com/u/bardos)\ **Post date:** [May 27, 2016, 7:05am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/11 "2016-05-27T07:05:56Z")
I have a strange perspective on fire. I have always viewed fire as some sort of living organic being, trying to survive at all costs, just like any human being or animal would. Very fierce in its survival mechanism. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 27, 2016, 7:08am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/12 "2016-05-27T07:08:59Z")
> [@Richox](#): > > A slightly more involved description. Generally solids don’t burn in the obvious way, they get hot enough to begin releasing vapours that do burn. If you lower the temperature of the burning item sufficiently, the vapor release stops, and therefore the fire does not continue. Hence some things can’t be controlled with water… Their vapor release point is lower than the possible cooling effect of water. For a heavily engaged fire, a sensible temperature for that to occur is 90ish deg C True, although solids do burn directly. When you see glowing embers without flame, that’s a solid burning. Steel wool burns similarly. ---
**Author:** ![Anaglyph](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anaglyph](https://boards.straightdope.com/u/Anaglyph)\ **Post date:** [May 27, 2016, 8:45am UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/13 "2016-05-27T08:45:30Z")
> [@bordelond](#): > > Slight tangent: > > What elemental sodium does when placed in water … is that properly called “burning”? Or is that reaction better described in other terms? You have the redox reaction of 2Na(s) + 2H2O → 2NaOH(aq) + H2(g) So, sodium is so reactive that it can use water as oxydizing agent, releasing reduced hydrogen as a biproduct. The reaction is so exotermic that it ignites the released H2, which burns with air oxygen to produce water ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [May 27, 2016, 4:24pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/14 "2016-05-27T16:24:30Z")
> [@Duckster](#): > > [Fire Triangle](https://en.wikipedia.org/wiki/Fire_triangle). You can actually go further for a “fire tetrahedron”, heat, fuel, oxygen, and a sustained reaction. Some firefighting agents like halon, work by chemically disrupting the reaction with no significant cooling or blanketing effect. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [May 27, 2016, 4:44pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/15 "2016-05-27T16:44:12Z")
You can gain insight (and a lot of entertainment) into what burning means by learning about interesting compounds such as Chlorine Trifluoride. [Sand Won’t Save You This Time](http://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time) > [@](#): > > The compound also a stronger oxidizing agent than oxygen itself… It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention **asbestos** , **sand** , and water-with which it reacts explosively. The link and excerpt above are from chemist Derek Lowe’s “Things I won’t Work With” blog - if you google that you can find many more fun tales. FOOF is another favorite. And an interest in burning leads naturally to exploding, so check out Azidoazide Azides. There’s also a great book about the history of rocket fuels called “Ignition!”, by John Clark - you can find a pdf online for free, e.g. here: > **[ignition.pdf](https://library.sciencemadness.org/library/books/ignition.pdf)** > > 3.52 MB ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [May 27, 2016, 4:57pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/16 "2016-05-27T16:57:04Z")
> [@watchwolf49](#): > > So water removes the heat, so it’s too cool for fire. That’s right, but there’s an interesting reason why water is so effective here, and it’s something called the latent heat of evaporation. Picture this: if you have a small container of 100 grams of water at room temperature, you may recall from school that it takes 1 calorie of heat to change the temperature of 1 g of water by 1 degree C. So every 100 calories of heat you add changes the temperature of our container by 1 degree. After we’ve added about 7800 calories, our 100 g of water will be heated up to the boiling point. Now the question is: how much more heat will it take to change this 100 g of water at 100 C to 100 g of water vapor at 100 C? The answer is surprisingly large: it will take 54,000 calories. It only took 7800 to heat it up from room temperature to boiling, but it takes 54,000 more to change it to vapor, without even increasing its temperature any. So for a fire to keep burning, it has to be above the temperature where water vaporizes, but to get to that point, it sucks a HUGE amount of the heat out of the fire for every gram of water that’s on it. By the way, that latent heat thing is also why steam burns you so badly - for every gram of water vapor that condenses on you, your skin gets 540 calories. And it’s why a cold drink gets warmed up so much by water condensing onto the glass on a humid day. ---
**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:** [May 27, 2016, 5:11pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/17 "2016-05-27T17:11:56Z")
> [@Riemann](#): > > You can gain insight (and a lot of entertainment) into what burning means by learning about interesting compounds such as Chlorine Trifluoride. > [Sand Won’t Save You This Time](http://blogs.sciencemag.org/pipeline/archives/2008/02/26/sand_wont_save_you_this_time) > The link and excerpt above are from chemist Derek Lowe’s “Things I won’t Work With” blog - if you google that you can find many more fun tales. FOOF is another favorite. And an interest in burning leads naturally to exploding, so check out Azidoazide Azides. > > There’s also a great book about the history of rocket fuels called “Ignition!”, by John Clark - you can find a pdf online for free, e.g. here: > [http://library.sciencemadness.org/library/books/ignition.pdf](http://library.sciencemadness.org/library/books/ignition.pdf) I only took a couple of 100-level chemistry courses, so it’s difficult for me to wrap my head around the notion that a nolecule with no oxygen in it could be such a potent oxidizer. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [May 27, 2016, 5:36pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/18 "2016-05-27T17:36:54Z")
> [@jz78817](#): > > I only took a couple of 100-level chemistry courses, so it’s difficult for me to wrap my head around the notion that a nolecule with no oxygen in it could be such a potent oxidizer. Yeah, _oxidizer_ is a bad name, although there’s historical reasons for it. It should be called _de-electronizer_. ---
**Author:** ![notsoheavyd3](https://avatars.discourse-cdn.com/v4/letter/n/85e7bf/32.png) [@notsoheavyd3](https://boards.straightdope.com/u/notsoheavyd3)\ **Post date:** [May 27, 2016, 9:22pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/19 "2016-05-27T21:22:55Z")
> [@jz78817](#): > > I only took a couple of 100-level chemistry courses, so it’s difficult for me to wrap my head around the notion that a nolecule with no oxygen in it could be such a potent oxidizer. Actually the easiest way to understand this is to look at the periodic table.(But ignore the noble gases) As you go up and right things become better oxidizers and as you go up and left you get things that reduce more easily. Since fluorine is on the upper right (except for helium) it’s a better oxidizer than anything including oxygen. Hydrogen and sodium are in the upper left so they’re really good at reducing. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [May 27, 2016, 10:12pm UTC](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776/20 "2016-05-27T22:12:44Z")
> [@notsoheavyd3](#): > > Actually the easiest way to understand this is to look at the periodic table.(But ignore the noble gases) As you go up and right things become better oxidizers and as you go up and left you get things that reduce more easily. Since fluorine is on the upper right (except for helium) it’s a better oxidizer than anything including oxygen. Hydrogen and sodium are in the upper left so they’re really good at reducing. Does this imply that hydrogen + fluorine compounds would be about as unstable/corrosive/toxic/exothermic as compounds can be? What difference, if any, is there between burning and corrosion except the timeframe? [Next page](https://boards.straightdope.com/t/why-does-water-put-fire-out/755776.md?page=2)