# Does odor have mass? **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2011, 3:53pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455 "2011-07-18T15:53:08Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![phreesh](https://avatars.discourse-cdn.com/v4/letter/p/9fc29f/32.png) [@phreesh](https://boards.straightdope.com/u/phreesh)\ **Post date:** [July 18, 2011, 3:53pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/1 "2011-07-18T15:53:08Z")
I’m pretty sure odor is stuff from the smelly thing leaving the smelly thing and entering your nose. So, if you leave a smelly thing in a box for a long enough time, will the odor ‘molecules’ leave the smelly thing and in the end, all you’d have is odor and the smelly thing would turn into pure odor (Sounds like something out of the Princess Bride or something - a vile of purist odor)? Put another way, are smelly things being slowly (very slowly) eroded simply by the act of being smelly? Also, does everything have a smell? Is everthing giving off odors? ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [July 18, 2011, 3:59pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/2 "2011-07-18T15:59:50Z")
I’ve wondered this too. Odor is caused by chemicals that enter your nose, so in a closed system, it would seem that any odorous object is either 1) going to dissipate into nothingness, 2) reach a point where it is odorless because all of the odoriferous chemicals exposed to the elements that are in such a state as to break away have already dissipated, or 3) reach an equilibrium where something else is feeding the odor cycle, such as bacteria and food for said bacteria being brought on the wind and deposited on the object, producing more odor. Now, I would expect that #2 may take a while, possibly longer than your life. ---
**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:** [July 18, 2011, 4:07pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/3 "2011-07-18T16:07:49Z")
Yes, odors have mass, and a thing which is producing odors is losing mass in the process. It probably won’t evaporate away completely, though: More likely, you’ll just lose all of the volatiles, and eventually be left with a pile of no-longer-smelly residue. If the smelly thing is sealed in a box, then this becomes a little more complicated: Not only can smelly molecules escape the surface of the thing and become airborne, but airborne smelly molecules can also attach themselves back to the surface of the thing. You’ll reach some equilibrium level of airborne stink where these two processes cancel each other out. And all substances will emit molecules to some degree, but for some (most metals, for instance), that degree is incredibly tiny at room temperature, such that you never actually need to worry about it. And even of those things which do emit significant amounts of molecules, not all of those are things that can be detected by your nose. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [July 18, 2011, 4:14pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/4 "2011-07-18T16:14:07Z")
Atoms have mass. Electrons have mass. Certainly odor has mass. 😉 ---
**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:** [July 18, 2011, 5:35pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/5 "2011-07-18T17:35:05Z")
yep. can’t have odor without molecules. molecules have mass. ---
**Author:** ![Hyperelastic](https://avatars.discourse-cdn.com/v4/letter/h/a3d4f5/32.png) [@Hyperelastic](https://boards.straightdope.com/u/Hyperelastic)\ **Post date:** [July 18, 2011, 7:46pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/6 "2011-07-18T19:46:05Z")
> [@robert\_columbia](#): > > Now, I would expect that #2 may take a while, possibly longer than your life. I thought this once, but it turned out I’d just eaten too much cheese. ---
**Author:** ![Jake](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@Jake](https://boards.straightdope.com/u/Jake)\ **Post date:** [July 18, 2011, 7:49pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/7 "2011-07-18T19:49:49Z")
I wonder, when I’m buried, how long do I smell? (No, not through my nose, I hope) 🙂 Y’know, just in case someone digs me up. I want to be pristine. 😃 ---
**Author:** ![phreesh](https://avatars.discourse-cdn.com/v4/letter/p/9fc29f/32.png) [@phreesh](https://boards.straightdope.com/u/phreesh)\ **Post date:** [July 18, 2011, 9:45pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/8 "2011-07-18T21:45:08Z")
So, to be clear, there are things in existence that have zero odor? Completely unsmellable? ---
**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:** [July 18, 2011, 10:01pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/9 "2011-07-18T22:01:42Z")
Completely unsmellable to the human nose, at least. But you could probably build a detector that could smell even something like gold (though you’d probably need to let it run for a very long time). ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [July 19, 2011, 12:57am UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/10 "2011-07-19T00:57:22Z")
I don’t think [coprolites](http://en.wikipedia.org/wiki/Coprolite)smell the same as they did when they were fresh. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [July 19, 2011, 1:04am UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/11 "2011-07-19T01:04:04Z")
> [@phreesh](#): > > So, to be clear, there are things in existence that have zero odor? Completely unsmellable? Pure water is odorless. Other things are, too. (Actually, seems odd to me that it would be, from an evolutionary standpoint, given the importance of being able to find it.) ---
**Author:** ![typoink](https://avatars.discourse-cdn.com/v4/letter/t/ecb155/32.png) [@typoink](https://boards.straightdope.com/u/typoink)\ **Post date:** [July 19, 2011, 1:45am UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/12 "2011-07-19T01:45:17Z")
> [@CookingWithGas](#): > > Pure water is odorless. Other things are, too. > > (Actually, seems odd to me that it would be, from an evolutionary standpoint, given the importance of being able to find it.) H20 is odorless. Naturally-located bodies of fresh water often less so. ---
**Author:** ![carnut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnut/32/3531_2.png) [@carnut](https://boards.straightdope.com/u/carnut)\ **Post date:** [July 19, 2011, 3:20am UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/13 "2011-07-19T03:20:42Z")
> [@kayaker](#): > > Atoms have mass. Electrons have mass. Certainly odor has mass. 😉 Catholics have Mass, which is much heavier. 😉 ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 19, 2011, 5:21am UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/14 "2011-07-19T05:21:17Z")
Well trying to find out more about volatile vs non-volatile substances I happened upon[this best answer](http://ask.metafilter.com/172747/Could-something-smell-so-much-that-it-entirely-disappears): > [@](#): > > All condensed matter (solids and liquids) has a vapor pressure specific to that material. That means that these substances will continually sublimate or evaporate into the surrounding environment until the partial pressure matches the vapor pressure. If that point is never met (if the surrounding environment is well ventilated, say), then the substance will eventually vanish into the gas phase. > > You can find the vapor pressure by looking at a phase diagram. At room temperature, for example, liquid water will evaporate until the partial pressure of water in the surrounding environment is about 3 kPa (3% of atmospheric pressure), then it will stop. Of course what we _smell_ are both substances that evaporate or sublimate easily under normal living conditions and that have been selected for our being consciously aware of at various concentrations. Clearly any particular object may have only some components that evaporate/sublimate to human detectable levels at room conditions. And humans can only detect in conditions within some range around those conditions … we don’t do too well in a near vacuum at 100C for example … ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [July 19, 2011, 12:29pm UTC](https://boards.straightdope.com/t/does-odor-have-mass/589455/15 "2011-07-19T12:29:09Z")
> [@CookingWithGas](#): > > Pure water is odorless. Other things are, too. > > (Actually, seems odd to me that it would be, from an evolutionary standpoint, given the importance of being able to find it.) It’s very easy to find water; your cells are filled with it and surrounded by it.