# Why is undiluted acetic acid "glacial"?

**URL:** <https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506>\
**Category:** Factual Questions\
**Created:** [December 9, 2012, 1:00pm UTC](https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506 "2012-12-09T13:00:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\
**Post date:** [December 9, 2012, 1:00pm UTC](https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506/1 "2012-12-09T13:00:37Z")

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Undiluted acetic acid is sold as “glacial acetic acid”. What is the origin of this nomenclature?

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**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\
**Post date:** [December 9, 2012, 1:09pm UTC](https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506/2 "2012-12-09T13:09:36Z")

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[Wikipedia](http://en.wikipedia.org/wiki/Glacial_acetic_acid):

> [@](#):
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> Glacial acetic acid is a trivial name for water-free (anhydrous) acetic acid. Similar to the German name Eisessig (ice-vinegar), the name comes from the ice-like crystals that form slightly below room temperature at 16.6 °C (61.9 °F) (the presence of 0.1% water lowers its melting point by 0.2 °C).

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**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\
**Post date:** [December 9, 2012, 1:19pm UTC](https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506/3 "2012-12-09T13:19:22Z")

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Ah there we go. Checked the wiki but apparently the browser search function does not look inside the different sections of an article, which are minimized when the mobile version is displayed.

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**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\
**Post date:** [December 10, 2012, 11:15am UTC](https://boards.straightdope.com/t/why-is-undiluted-acetic-acid-glacial/643506/4 "2012-12-10T11:15:40Z")

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In my university chem lab it was a rule of thumb that when the glacial acetic acid froze we could nag them to put the heating on.