# Chemical that changes color in the presense of urine?

**URL:** <https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545>\
**Category:** Factual Questions\
**Created:** [August 6, 2006, 11:13am UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545 "2006-08-06T11:13:42Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\
**Post date:** [August 6, 2006, 11:13am UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545/1 "2006-08-06T11:13:42Z")

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I was at a pool party yesterday and some of the people started joking that the one person looked so content in his pool chair that he was probably taking a leak.

The owner of the pool said that he had put chemicals in place that turned green if anyone were to urninate in his pool.

Which made everyone wonder if such a chemical existed. (it need not turn green, just change colors.)

Q1. Is there such a checmical?  
Q2. If there is, would it be dangerous (as I suspect) having it in the pool.

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**Author:** ![Hogwash](https://avatars.discourse-cdn.com/v4/letter/h/a88e57/32.png) [@Hogwash](https://boards.straightdope.com/u/Hogwash)\
**Post date:** [August 6, 2006, 11:17am UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545/2 "2006-08-06T11:17:56Z")

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You will find much enlightenment [here](http://www.snopes.com/science/poolpiss.htm).

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**Author:** ![glee](https://avatars.discourse-cdn.com/v4/letter/g/b5a626/32.png) [@glee](https://boards.straightdope.com/u/glee)\
**Post date:** [August 6, 2006, 11:51am UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545/3 "2006-08-06T11:51:33Z")

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After this happened, many people stopped going to public pools (including me).  
Yeuchh.

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**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\
**Post date:** [August 6, 2006, 1:40pm UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545/4 "2006-08-06T13:40:19Z")

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I researched this for a Staff Report for Cecil, and was unable to find anything either. Doesn’t mean there isn’t, but I spent some time searching online, and calling pool/chemical supply places and asking a lot of amused-sounding wiseacres. I’ve been debating whether or not it’s worth publishing “can’t find nothin’, sorry”.

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [August 6, 2006, 1:57pm UTC](https://boards.straightdope.com/t/chemical-that-changes-color-in-the-presense-of-urine/367545/5 "2006-08-06T13:57:40Z")

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> [@Una Persson](#):
>
> I researched this for a Staff Report for Cecil, and was unable to find anything either.

[Ninhydrin](http://en.wikipedia.org/wiki/Ninhydrin) might be made to work, but it would have the disadvantage of turning anyone who swam in the pool purple.  
Some would say that’s a small price to pay, others would complain about being graped.