# Why no "pure" hydrogen peroxide? **URL:** \ **Category:** Factual Questions\ **Created:** [January 24, 2008, 4:55pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827 "2008-01-24T16:55:14Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [January 24, 2008, 4:55pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/1 "2008-01-24T16:55:14Z")
Most commercially available H[sub]2[/sub]O[sub]2[/sub] is available as a “solution” (something like 5%, IIRC). Anyway: Why isn’t “pure” H[sub]2[/sub]O[sub]2[/sub] sold? My WAG is cost and practicality, that most consumer applications work fine with just a solution, and that by putting it in a solution, it goes a lot longer (for the manufacturer). I’ve always assumed that drinking H[sub]2[/sub]O[sub]2[/sub] would not be good for me. Would I get sick, either with the solution or the pure stuff? ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [January 24, 2008, 5:08pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/2 "2008-01-24T17:08:19Z")
I actually learned quite a bit reading through the wiki… I just figured it was pretty caustic in higher concentrations, but I had no idea straight hydrogen peroxide was a rocket propellent. > [@](#): > > Hydrogen peroxide works best as a propellant in extremely high concentrations-- roughly over 70%. Although any concentration of peroxide will generate some hot gas (oxygen plus some steam), at concentrations above approximately 67%, the heat of decomposing hydrogen peroxide becomes large enough to completely vaporize all the liquid at standard temperature. This represents a safety and utilization turning point, since decomposition of any concentration above this amount is capable of transforming the liquid entirely to heated gas (the higher the concentration, the hotter the resulting gas). This very hot steam/oxygen mixture can then be used to generate maximal thrust, power, or work, but it also makes explosive decomposition of the material far more hazardous. > **[Hydrogen peroxide](https://en.wikipedia.org/wiki/Hydrogen_peroxide)** > > .mw-parser-output .ib-chembox{border-collapse:collapse;text-align:left}.mw-parser-output .ib-chembox td,.mw-parser-output .ib-chembox th{border:1px solid #a2a9b1;width:40%}.mw-parser-output .ib-chembox td+td{width:60%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .ib-chembox figure:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent){background:var(--background-color-inverted,#f8f9fa)}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-pa... ---
**Author:** ![Tapioca\_Dextrin](https://avatars.discourse-cdn.com/v4/letter/t/3d9bf3/32.png) [@Tapioca\_Dextrin](https://boards.straightdope.com/u/Tapioca_Dextrin)\ **Post date:** [January 24, 2008, 5:13pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/3 "2008-01-24T17:13:48Z")
[QUOTE=Earl Snake-Hips Tucker] I’ve always assumed that drinking H[sub]2[/sub]O[sub]2[/sub] would not be good for me. Would I get sick, either with the solution or the pure stuff? [/QUOTE] From the [MSDS](http://www.bu.edu/es/labsafety/ESMSDSs/MSHydPeroxide.html#anchor888417) > [@](#): > > Danger! Strong oxidizer. Contact with other material may cause a fire. Harmful if inhaled. Corrosive. Causes eye and skin burns. May cause severe respiratory tract irritation with possible burns. May cause severe digestive tract irritation with possible burns. > Target Organs: None known. > > Potential Health Effects > Eye: > Causes eye burns. Produces irritation, characterized by a burning sensation, redness, tearing, inflammation, and possible corneal injury. > Skin: > Causes skin burns. > Ingestion: > May cause severe and permanent damage to the digestive tract. Causes gastrointestinal tract burns. May cause perforation of the digestive > tract. May cause severe digestive tract irritation with abdominal pain, nausea, vomiting and diarrhea. > Inhalation: > Harmful if inhaled. May cause irritation of the respiratory tract with burning pain in the nose and throat, coughing, wheezing, > shortness of breath and pulmonary edema. Causes chemical burns to the respiratory tract. May cause ulceration of nasal tissue, insomnia, nervous tremors with numb extremities, chemical pneumonia, unconsciousness, and death. > Chronic: > Prolonged or repeated skin contact may cause dermatitis. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 24, 2008, 5:18pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/4 "2008-01-24T17:18:18Z")
Hydrogen peroxide is a very strong oxidizing agent, and is not very stable. It spontaneously decomposes into water and oxygen, releasing heat in the process. At very high concentrations (\>70%) , the heat released during decomposition can actually vaporize the remaining liquid. Because it spontaneously decomposes, concentrated hydrogen peroxide has to be stored in special vented containers. As the concentration increases, it gets progressively more dangerous. High concentrations of hydrogen peroxide spilled on clothing or other combustible materials can cause the material to spontaneously combust. High concentrations spilled on skin causes severe chemical burns. If you drank pure hydrogen peroxide, it would kill you, and it wouldn’t be pleasant. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [January 24, 2008, 5:23pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/5 "2008-01-24T17:23:40Z")
[QUOTE=robby] If you drank pure hydrogen peroxide, it would kill you, and it wouldn’t be pleasant. [/QUOTE] From this and the above posts, I’m imagining a death somewhat along the lines of the one sufferred by the hapless “lucky shot” gunnery officer on Captain Kruge’s bird of prey. Owie. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [January 24, 2008, 5:26pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/6 "2008-01-24T17:26:04Z")
[QUOTE=steronz] I actually learned quite a bit reading through the wiki… I just figured it was pretty caustic in higher concentrations, but I had no idea straight hydrogen peroxide was a rocket propellent. > **[Hydrogen peroxide](https://en.wikipedia.org/wiki/Hydrogen_peroxide)** > > .mw-parser-output .ib-chembox{border-collapse:collapse;text-align:left}.mw-parser-output .ib-chembox td,.mw-parser-output .ib-chembox th{border:1px solid #a2a9b1;width:40%}.mw-parser-output .ib-chembox td+td{width:60%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .ib-chembox figure:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent){background:var(--background-color-inverted,#f8f9fa)}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-pa... [/QUOTE] First Astronaut: My God! Why is there a corpse of a naked blonde in orbit? Second Astronaut, looking closer: She’s not a _natural_ blonde. 😃 ---
**Author:** ![Solfy](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@Solfy](https://boards.straightdope.com/u/Solfy)\ **Post date:** [January 24, 2008, 5:52pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/7 "2008-01-24T17:52:36Z")
I’ve worked with 30% hydrogen peroxide. It has to be kept refrigerated at all times. It comes in a special vapor venting bottle. It’s not pure liquid evil, but close to it. I got some residue from the outside of the bottle on my hand when putting it back in the fridge. The skin on the surface of my hand died off where it touched. With many things in life, concentration matters. There are a lot of chemicals that are beneficial in small amounts that will kill you in large amounts. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [January 24, 2008, 6:48pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/8 "2008-01-24T18:48:50Z")
Concentrated H2O2 was used to power torpedoes… ---
**Author:** ![Solfy](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@Solfy](https://boards.straightdope.com/u/Solfy)\ **Post date:** [January 24, 2008, 7:23pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/9 "2008-01-24T19:23:04Z")
[QUOTE=Raft] What percentage is used to bleach hair? Not the 3% we use as antiseptic is it? [/QUOTE] Hairdressers’ hydrogen peroxide is sold in “volume” levels of 10, 20, and 30 (and possibly 40). The 10 volume approximately corresponds to the 3% you mention, with the 40 volume working out to about 15%. There’s a good explanation on the [H2O2 wiki](http://en.wikipedia.org/wiki/Hydrogen_peroxide). ---
**Author:** ![Cluricaun](https://avatars.discourse-cdn.com/v4/letter/c/bb73d2/32.png) [@Cluricaun](https://boards.straightdope.com/u/Cluricaun)\ **Post date:** [January 24, 2008, 7:53pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/10 "2008-01-24T19:53:06Z")
If all this is true (and I know it is) then what in the hell is [this food grade hydrogen peroxide stuff?](http://www.dfwx.com/goewebsite.htm) ---
**Author:** ![Solfy](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@Solfy](https://boards.straightdope.com/u/Solfy)\ **Post date:** [January 24, 2008, 8:13pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/11 "2008-01-24T20:13:38Z")
[QUOTE=Cluricaun] If all this is true (and I know it is) then what in the hell is [this food grade hydrogen peroxide stuff?](http://www.dfwx.com/goewebsite.htm) [/QUOTE] Frankly I’m sort of surprised they make this available to consumers, but then one can aquire all sorts of lovely things off the internet these days, no? One can get up to 50% from [Aldrich](http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIAL/516813), but I don’t believe they’ll ship that off to just anyone. The disclaimer on that site amuses: > [@](#): > > UPDATE: Can 35% food grade hydrogen peroxide be used for making chemical bombs? > With recent publicity of a terror plot involving using “peroxide”, questions have arisen whether 35% concentration hydrogen peroxide could be used to make explosives? The answer is no. 35% hydrogen peroxide is by volume 35% h2o2 and 65% h2o (water). Unless a person could figure how to make an explosive device from water, there is no manner to use 35% concentration hydrogen peroxide to make any explosive device or compound. I see no mention of handling precautions, oh, wait, it’s on another page: > [@](#): > > WHY IS HYDROGEN PEROXIDE NOT SOLD IN HEALTH SUPPLEMENT STORES ? > While some now do, most do not. The primary reason is to avoid lawsuits founded in foolishness of some people and because of limited shelf life. 35% Food Grade hydrogen peroxide should be stored in a cool, completely dark location - which does not lend itself to retail over-the-counter sales. Right. . . ---
**Author:** ![Barrington](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Barrington](https://boards.straightdope.com/u/Barrington)\ **Post date:** [January 24, 2008, 8:28pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/12 "2008-01-24T20:28:18Z")
[QUOTE=beowulff] Concentrated H2O2 was used to power torpedoes… [/QUOTE] Also submarines (the WWII German Walther turbine), but never made it into production mainly because of the storage and handling difficulties and dangers. Post-war, the US Navy experimented the same way based on the Walther design, but abandoned the project for similar reasons. As someone at the time concluded “hydrogen peroxide and submarines just don’t mix”. The reason that both countries were experimenting with this means of propulsion was that it would give subs (which at the time were all diesel-electric) hugely extended submerged times as well as very high underwater speed. ---
**Author:** ![Bobotheoptimist](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@Bobotheoptimist](https://boards.straightdope.com/u/Bobotheoptimist)\ **Post date:** [January 24, 2008, 8:56pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/13 "2008-01-24T20:56:53Z")
The second coolest classroom demonstration in “Chemistry of Hazardous Materials” was pouring hydrogen peroxide on assorted substances and watching them ignite. For a while after, I eyed the bubbling peroxide on various scratches and scrapes with suspicion. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [January 24, 2008, 10:22pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/14 "2008-01-24T22:22:03Z")
[QUOTE=Bobotheoptimist] The second coolest classroom demonstration in “Chemistry of Hazardous Materials” was pouring hydrogen peroxide on assorted substances and watching them ignite. For a while after, I eyed the bubbling peroxide on various scratches and scrapes with suspicion. [/QUOTE] Not to mention using it loosen ear wax. OTOH, the bottle of 3% medicinal hydrogen peroxide tells you to gargle with the stuff. That’s where I draw the line. ---
**Author:** ![Max\_Torque](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)\ **Post date:** [January 24, 2008, 10:34pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/15 "2008-01-24T22:34:29Z")
[QUOTE=yabob] Not to mention using it loosen ear wax. OTOH, the bottle of 3% medicinal hydrogen peroxide tells you to gargle with the stuff. That’s where I draw the line. [/QUOTE] Done that. Actually, in my experience, the bottle tells you to dilute the amount you’re going to gargle with an equal amount of water, which leaves you with a 1.5% solution if my elementary math skills are correct. Anyway, it didn’t taste bad at all; didn’t taste like anything, really. Foamed like a mofo, though, and required a couple of spits to relieve the pressure to continue swishing. Sure does make your mouth feel squeaky clean afterwards. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 24, 2008, 10:35pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/16 "2008-01-24T22:35:35Z")
[QUOTE=yabob] That’s where I draw the line. [/QUOTE] Before or after gargling? If after, [Catalase](http://en.wikipedia.org/wiki/Catalase) will protect you, and provide your mouth with a burst of oxygeny goodness. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [January 24, 2008, 11:02pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/17 "2008-01-24T23:02:40Z")
[QUOTE=robby] Hydrogen peroxide is a very strong oxidizing agent, and is not very stable. It spontaneously decomposes into water and oxygen, releasing heat in the process. At very high concentrations (\>70%) , the heat released during decomposition can actually vaporize the remaining liquid. Because it spontaneously decomposes, concentrated hydrogen peroxide has to be stored in special vented containers. As the concentration increases, it gets progressively more dangerous. High concentrations of hydrogen peroxide spilled on clothing or other combustible materials can cause the material to spontaneously combust. High concentrations spilled on skin causes severe chemical burns. If you drank pure hydrogen peroxide, it would kill you, and it wouldn’t be pleasant. [/QUOTE] To add to the joys of hydrogen peroxide, you have to realize that when it decomposes into water and oxygen, you’re getting \*individual \* oxygen atoms. Oxygen doesn’t like going around like that. It wants to be happily settled down as part of a molecule. It will form molecules by itself (as about 19% of the atmosphere attests) but, while it’s temporarily in atomic form, it isn’t too fussy about what it can get. Think of it as a 2am barfly with serious beer goggles - any hookup at all counts as a score. You may have seen that thing you do with magnesium ribbon where you light it and let it burn brightly in air, and then put it in a jar full of pure oxygen where it blazes much, much brighter. That’s the different between 19% oxygen and 100% oxygen. Well, atomic oxygen ramps it up a step further. Be moderately afraid. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 24, 2008, 11:25pm UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/18 "2008-01-24T23:25:38Z")
[QUOTE=beowulff] Concentrated H2O2 was used to power torpedoes… [/QUOTE] And [rocket planes](http://en.wikipedia.org/wiki/Me_163_Komet). Rocket planes that had a disturbing tendency to spontaneously explode on take-off, landing, or for no explicable reason while sitting on a flight line. ---
**Author:** ![Bewildebeest](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@Bewildebeest](https://boards.straightdope.com/u/Bewildebeest)\ **Post date:** [January 25, 2008, 12:11am UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/19 "2008-01-25T00:11:01Z")
And torpedo propellant. The [explode at the wrong time kind](http://en.wikipedia.org/wiki/Russian_submarine_Kursk_explosion) . ---
**Author:** ![The\_Scrivener](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@The\_Scrivener](https://boards.straightdope.com/u/The_Scrivener)\ **Post date:** [January 25, 2008, 1:59am UTC](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827/20 "2008-01-25T01:59:44Z")
For more on HTP-fueled torpedoes and the 2000 sinking of the Russian nuclear submarine _Kursk_, there’s [this thread](http://boards.straightdope.com/sdmb/showthread.php?t=315813&highlight=Kursk+peroxide). That French conspiracy-theory film cited in the Wiki article sounds like complete BS, BTW. [Next page](https://boards.straightdope.com/t/why-no-pure-hydrogen-peroxide/434827.md?page=2)