# Freezing point of toothpaste **URL:** \ **Category:** Factual Questions\ **Created:** [December 24, 1999, 8:11pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579 "1999-12-24T20:11:00Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [December 24, 1999, 8:11pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/1 "1999-12-24T20:11:00Z")
My brother was travelling through Dayton, Ohio last night and he left his luggage in the trunk of his car for several hours. When he got to his hotel room and tried to brush his teeth, he couldn’t as his toothpaste was frozen (or at least couldn’t move by squeezing the tube as hard as he possibly could.) So, at what temperature does the average toothpaste freeze at? The toothpaste was inside a suitcase, so it should have been insulated somewhat. ---
**Author:** ![Ursa\_Major](https://avatars.discourse-cdn.com/v4/letter/u/a88e57/32.png) [@Ursa\_Major](https://boards.straightdope.com/u/Ursa_Major)\ **Post date:** [December 24, 1999, 8:24pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/2 "1999-12-24T20:24:00Z")
The solvent used in toothpaste is a hydroxide liquid commonly known as water. Freezing point: 0 degrees celcius. ---
**Author:** ![Doctordec](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@Doctordec](https://boards.straightdope.com/u/Doctordec)\ **Post date:** [December 25, 1999, 2:12am UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/3 "1999-12-25T02:12:00Z")
Wait a minute. If it’s baking soda toothpaste wouldn’t it freeze lower than that. Seems the soda might act just like salt and keep it plastic just a little lower. Just how does one brush one’s teeth on Everest anyhow ?? * * * “Hope is not a method” ---
**Author:** ![BobT](https://avatars.discourse-cdn.com/v4/letter/b/8e8cbc/32.png) [@BobT](https://boards.straightdope.com/u/BobT)\ **Post date:** [December 25, 1999, 7:28am UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/4 "1999-12-25T07:28:00Z")
I had assumed that the other materials in toothpaste would have affected the freezing point. However, I can accept 0 celsius. ---
**Author:** ![funneefarmer](https://avatars.discourse-cdn.com/v4/letter/f/9fc348/32.png) [@funneefarmer](https://boards.straightdope.com/u/funneefarmer)\ **Post date:** [December 25, 1999, 10:56am UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/5 "1999-12-25T10:56:00Z")
Well back when I was a young whipper-snapper my mother had us use plain old baking soda when we ran out of regular toothpaste. My cousins after staying over one night distinctly remember it even now and comment on how they now buy baking soda toothpaste for their kids. So if you need a toothpaste that won’t freeze, some baking soda on a brush will do just fine. ---
**Author:** ![Doctordec](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@Doctordec](https://boards.straightdope.com/u/Doctordec)\ **Post date:** [December 25, 1999, 3:45pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/6 "1999-12-25T15:45:00Z")
Good point. I forgot about it but I used to use “tooth powder” made by Pepsodent and it was packaged in a can and was sold with the toothpaste. I think you can still buy it. I figured it was cheaper than toothpaste. * * * “Hope is not a method” ---
**Author:** ![Konrad](https://avatars.discourse-cdn.com/v4/letter/k/f475e1/32.png) [@Konrad](https://boards.straightdope.com/u/Konrad)\ **Post date:** [December 25, 1999, 4:14pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/7 "1999-12-25T16:14:00Z")
Ursa: According to my chemistry teacher anything that dissolves in water will lower its freezing point. ---
**Author:** ![Ursa\_Major](https://avatars.discourse-cdn.com/v4/letter/u/a88e57/32.png) [@Ursa\_Major](https://boards.straightdope.com/u/Ursa_Major)\ **Post date:** [December 25, 1999, 5:11pm UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/8 "1999-12-25T17:11:00Z")
My assumption (probably wrong) was that the powder in toothpaste is no more dissolved in water than, say, dirt is dissolved in water when it makes mud. “Suspended in” sounds closer to the mark. Personal observation has convinced me that mud freezes at the same temp as water. Water is the component that makes toothpaste malleable, the powder technically has a freezing point of several hundred degrees (just below its melting point). Of course, I’m willing to be convinced otherwise, since I haven’t taken a chemistry class in 20 years. ---
**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:** [December 27, 1999, 5:41am UTC](https://boards.straightdope.com/t/freezing-point-of-toothpaste/5579/9 "1999-12-27T05:41:00Z")
My Colgate toothpaste lists glycerin as the most abundant ingredient. Glycerin in a 67% solution with water has a [freezing point](http://www.sy-kogyo.co.jp/therma3.htm) of -47 degrees Celcius, so it is not surprising that your toothpaste did not freeze. * * * TT “Believe those who seek the truth. Doubt those who find it.” --Andre Gide