# Will Hydrogen Peroxide degrade if I mix it with water?
**URL:** https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351
**Category:** Factual Questions
**Created:** [September 13, 2002, 9:15pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351 "2002-09-13T21:15:40Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)
#### Post date: [September 13, 2002, 9:15pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/1 "2002-09-13T21:15:40Z")
If I keep Hydrogen Peroxide in an airtight container with tap water, will it’s potency degrade (besides the dilution)? If it will because of whatever organisms might be in tap water, would it be significant and would distilled water solve the problem. Also, how fast would it degrade?
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### Author:  [@Padeye](https://boards.straightdope.com/u/Padeye)
#### Post date: [September 13, 2002, 10:21pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/2 "2002-09-13T22:21:34Z")
There shouldn’t be any degradation unless there is something with the peroxide to react with. Drugstore peroxide is only 2% strength in water and it doesn’t seem to lose potency.
Warning, be careful what you put high strength perodixe solutions in. A few years ago a man was killed when he drank undiluted peroxide his father stored in a water jug in the refrigerator. I’ll look up a cite but I’m pretty sure it was discussed here.
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### Author:  [@Squink](https://boards.straightdope.com/u/Squink)
#### Post date: [September 13, 2002, 11:07pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/3 "2002-09-13T23:07:33Z")
Iron, manganese or other heavy metal ions in tap water will catalyze the breakdown of H[sub]2[/sub]O[sub]2[/sub]. You _may_ be OK, but it’s safer to use distilled or deionized water.
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### Author:  [@Mangetout](https://boards.straightdope.com/u/Mangetout)
#### Post date: [September 13, 2002, 11:35pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/4 "2002-09-13T23:35:20Z")
I was told that Hydrogen peroxide will break down if simply shaken or stored for too long; is that true?
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### Author:  [@Derleth](https://boards.straightdope.com/u/Derleth)
#### Post date: [September 13, 2002, 11:42pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/5 "2002-09-13T23:42:52Z")
**Mangetout** : Hydrogen peroxide (H[sub]2[/sub]O[sub]2[/sub]) is _constantly_ trying to turn into water and oxygen gas. It just doesn’t do it very fast under normal conditions: Stored for a while, degredation will be negligible. It will happen, though, and it will happen more quickly if energy is added to the system somehow (heat, for example, or maybe just vibration) or catalysts are introduced.
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### Author:  [@CrazyCatLady](https://boards.straightdope.com/u/CrazyCatLady)
#### Post date: [September 13, 2002, 11:47pm UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/6 "2002-09-13T23:47:43Z")
Actually, exposure to light is often enough to make hydrogen peroxide break down. The energy in the light is enough to drive the reaction at a pretty good rate. Didn’t you ever wonder why it’s sold in colored bottles instead of clear ones?
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### Author:  [@Squink](https://boards.straightdope.com/u/Squink)
#### Post date: [September 14, 2002, 12:45am UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/7 "2002-09-14T00:45:04Z")
[INTRODUCTION TO HYDROGEN PEROXIDE frequently asked questions](http://www.h2o2.com/intro/faq.html#2)
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### Author:  [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)
#### Post date: [September 14, 2002, 1:10am UTC](https://boards.straightdope.com/t/will-hydrogen-peroxide-degrade-if-i-mix-it-with-water/128351/8 "2002-09-14T01:10:15Z")
nice, thanks!