# Can bar soap "go bad"? **URL:** \ **Category:** Factual Questions\ **Created:** [May 23, 2010, 12:10am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415 "2010-05-23T00:10:43Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [May 23, 2010, 12:10am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/1 "2010-05-23T00:10:43Z")
While cleaning out a bathroom cupboard, I came across a stray bar of soap. From what I remember of my time here, I know this soap is many years old - over five, probably more. Is there any reason to not use this soap? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 23, 2010, 12:39am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/2 "2010-05-23T00:39:14Z")
Yes it can eventually, but modern standard bar soap should last many years if kept in a cool, dry place. See [Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos](http://answers.yahoo.com/question/index?qid=20060626171904AA2jeJ9) ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [May 23, 2010, 3:19am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/3 "2010-05-23T03:19:21Z")
Twelve years after moving, I found a bar of Ivory soap in an unpacked box. Opening the wrapper, it was brownish at the edges and somewhat dry, but looked OK otherwise. I used it, it seemed to work just fine. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [May 23, 2010, 3:38am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/4 "2010-05-23T03:38:20Z")
Here’s a question, then. What is the negative effect of using “bad” soap? Can it hurt you or does is just no longer do its job? ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [May 23, 2010, 1:07pm UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/5 "2010-05-23T13:07:53Z")
I have had soap smell rancid. I wouldn’t use it, but I am sure it wouldn’t hurt you. Soap is made from fat and lye and the fat can certainly turn. ---
**Author:** ![Covered\_In\_Bees](https://avatars.discourse-cdn.com/v4/letter/c/7ab992/32.png) [@Covered\_In\_Bees](https://boards.straightdope.com/u/Covered_In_Bees)\ **Post date:** [May 23, 2010, 9:24pm UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/6 "2010-05-23T21:24:03Z")
> [@astro](#): > > Yes it can eventually, but modern standard bar soap should last many years if kept in a cool, dry place. > > See [Yahoo Search - Web Search](http://answers.yahoo.com/question/index?qid=20060626171904AA2jeJ9) Your cite is Yahoo Answers? Seriously? One of the richest collections of pure stupidity on the whole internet is your go to link? You couldn’t find anywhere else with a sufficient answer with a better reputation? ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [May 23, 2010, 9:31pm UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/7 "2010-05-23T21:31:41Z")
Soap that turns bad winds up in prison. Do not bend over in the prison shower to pick up the bad soap. ---
**Author:** ![Cheshire\_Human](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Cheshire\_Human](https://boards.straightdope.com/u/Cheshire_Human)\ **Post date:** [May 23, 2010, 10:08pm UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/8 "2010-05-23T22:08:30Z")
Speaking as someone who’s education is in chemistry, I can state definitively that “yes, it can go bad”, at least in the sense that in an atmosphere (like ours) that contains significant amounts of free oxygen, it will eventually oxidize. Depending on the storage conditions, however, it would take centuries or millenia before it stops working like soap. You are safe to use it if it’s younger than you are, or even if it’s only still in it’s original bar form. ETA: The packaging will probably deteriorate to uselessness before the soap itself does. 🙂 ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 23, 2010, 10:17pm UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/9 "2010-05-23T22:17:47Z")
> [@Covered\_In\_Bees](#): > > Your cite is Yahoo Answers? Seriously? One of the richest collections of pure stupidity on the whole internet is your go to link? You couldn’t find anywhere else with a sufficient answer with a better reputation? If the information offered (below) is correct and on point (and it is) I’ll link to the Onion. > [@](#): > > Bar soap can collect moisture in humid areas and get sticky. It can also dry out in areas like here in vegas, and crack and get brownish at the edges. Soap is made of fat and lye. oldfashioned soap that was made from animal fats could go rancid in hot weather too. ---
**Author:** ![susan\_foster](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@susan\_foster](https://boards.straightdope.com/u/susan_foster)\ **Post date:** [May 24, 2010, 2:33am UTC](https://boards.straightdope.com/t/can-bar-soap-go-bad/540415/10 "2010-05-24T02:33:24Z")
Homemade soap makers would talk about DOS - dreaded orange spots. They were spots that appeared on soap made with oil that went rancid.