Sciencemadness Discussion Board

Hydrogen peroxide maximum safe concentration

ChemistryForever - 9-1-2019 at 05:16

If you want to concentrate further a 30% H2O2 solution, and you want to go even over the 55% that some solutions are, what is the maximum concentration which is safe, so that it does not possess explosion risk ?

XeonTheMGPony - 9-1-2019 at 05:27

99% it depends what you store it in and around and your competence of handling it.

How can you figure out what is safe storage media you ask? Welcome to the world of material compatibility lists. read through several and find the consensus on the best material for storage.

[Edited on 9-1-2019 by XeonTheMGPony]

ChemistryForever - 9-1-2019 at 07:53

So I mean it is not an explosive if it is pure than other peroxides. So it cannot happen like I open a bottle with 100% hydrogen peroxide and it makes a boom.

XeonTheMGPony - 9-1-2019 at 08:12

Quote: Originally posted by ChemistryForever  
So I mean it is not an explosive if it is pure than other peroxides. So it cannot happen like I open a bottle with 100% hydrogen peroxide and it makes a boom.


So long as you used non reactive lid and jar no.

It decomposes to Oxygen and water, for there to be a boom there needs to be fuel as well.

If you spill it on you or some thing combustible how ever! then unconfined it simply bursts into flames.

Honestly, the fact you need to ask tells me you really should consider studying peroxide a lot more be for playing with it to any level of concentration above 30%, and even at 30% it can do your body damage.

XeonTheMGPony - 9-1-2019 at 08:26

https://en.wikipedia.org/wiki/Hydrogen_peroxide

https://webwiser.nlm.nih.gov/getSubstanceData.do?substanceId...

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&...

to get you started

unionised - 9-1-2019 at 08:41

Quote: Originally posted by XeonTheMGPony  


It decomposes to Oxygen and water, for there to be a boom there needs to be fuel as well.

Nope.
You don't need a fuel. The decomposition is exothermic and the heat released will decompose more peroxide.

Highly concentrated solutions can be made to explode. The vapour can detonate too.
https://pubs.acs.org/doi/abs/10.1021/je60020a040?journalCode...

If you do not know what you are talking about, you shouldn't be giving "advice"

XeonTheMGPony - 9-1-2019 at 08:44

Well less he plans to add catalyst or a blasting cap,which is all so why I mentioned competence in handling.

Perhaps read more links?

All so to get explosive decomposition in the true sense of a boom you need confinement.

Teacher heal thy self?

[Edited on 9-1-2019 by XeonTheMGPony]

j_sum1 - 9-1-2019 at 18:21

I am halfway through reading Ignition. (Which I reccomend btw). There are stories about high concentration peroxide that would make me extremely nervous about handling or storing it. Grease from a fingerprint becomes a fuel. Dust particles become a catalyst. Undiluted exothermic decomposition and you have a runaway. Boom. And this is a book that discusses ClF3 and hydrazine tetrafluoride quite casually.

This sounds like a bad idea unless you are working extremely low volume, have a immediate need, and have excellent cooling ability and a blast shield.

happyfooddance - 9-1-2019 at 20:21

Hydrogen peroxide is one common reagent that makes me uncomfortable. It is too unpredictable, and too powerful. Looks/moves/smells like water, doesn't react immediately with many things; but will also start doing strange unexpected things if you just let it sit in contact with (like some organic material that might just float around for 20 minutes, then all of the sudden start foaming or turning colors (or turning white).

It burns like hell, too, worse than H2SO4, though I've never spilled more than a few drops of either on my skin.

I feel like I had more to say with this post but I guess not.

Wear goggles.

woelen - 10-1-2019 at 00:21

Just for simplicity. In a home/hobby setting I would say, keep the concentration of hydrogen peroxide below 30...35%. Even at this concentration, it is a very powerful and also very corrosive (to skin, tissue) oxidizer, which is very unstable. If you want to see how violently it can decompose (simple catalytic decomposition to O2 and H2O), take a small spatula of KMnO4 and drip some 30% H2O2 on that. Do not use more than 0.5 ml for this experiment! You will be amazed!

Can you imagine what happens if a small crystal of KMnO4 comes into a bottle, full of 30% H2O2 :o ??


[Edited on 10-1-19 by woelen]

fusso - 10-1-2019 at 03:48

Quote: Originally posted by happyfooddance  
smells like water
What? But my ~30% H2O2 don't smell like water at all?? It smells even pungenter and stronger than Cl2 and NO2??? I dunno what should I associate its smell with.

[Edited on 190110 by fusso]

XeonTheMGPony - 10-1-2019 at 04:28

Quote: Originally posted by woelen  
Just for simplicity. In a home/hobby setting I would say, keep the concentration of hydrogen peroxide below 30...35%. Even at this concentration, it is a very powerful and also very corrosive (to skin, tissue) oxidizer, which is very unstable. If you want to see how violently it can decompose (simple catalytic decomposition to O2 and H2O), take a small spatula of KMnO4 and drip some 30% H2O2 on that. Do not use more than 0.5 ml for this experiment! You will be amazed!

Can you imagine what happens if a small crystal of KMnO4 comes into a bottle, full of 30% H2O2 :o ??


[Edited on 10-1-19 by woelen]


How I make O2 when I need it, Works with just MnO2.

I can say I have rarely ever needed to go over 35% that is my standard here as I can get gallons of it very cheap (Some people think it is smart to drink the stuff)

But take great caution when concentrating it, all glass wear is cleaned several times, then oven dried and protected from any contamination, then it is stored in all non sealed but covered glass containers.

It is not to be taken lightly, as I said it is one of those things that if you need to ask, you haven't researched it enough.

Go slow, and at each step experiment and test, so you have a handle of it.

35% requires good handling, if it gets on you you don't know till you feel the pain then it turns white the spot it hit. best to store in cold dark place and bottle needs to be vented every so often.

So study a crap load as it is not a light or simple thing to get into.

Felab - 10-1-2019 at 09:17

I would really fear it at arround 75% or higher. If even the 30% stuff I have is incredibly painful when you get it on your skin, I cannot imagine the 75% stuff.

You can concentrate H2O2 further than 35% by putting it in a desecator with H2SO4 or CaCl for a month or so.

My suggestions are you use impolute glassware and analytical grade H2O2. Also, measure its density every two days before it becomes too concentrated and impurities can make it explode and try it on a small scale so if something goes wrong it doesn't cause a disaster.

What do you exactly need extremely concentrated H2O2 for?

Felab - 10-1-2019 at 11:03

Quote: Originally posted by fusso  
Quote: Originally posted by happyfooddance  
smells like water
What? But my ~30% H2O2 don't smell like water at all?? It smells even pungenter and stronger than Cl2 and NO2??? I dunno what should I associate its smell with.

[Edited on 190110 by fusso]


If your H2O2 smells that strong, you might consider buying it from another supply. Mine smells like a hospital but nowhere near as pungent as chlorine.

ChemistryForever - 11-1-2019 at 16:10

I don't need concentrated H2O2 for anything. It was just a question.

FeedMe94 - 11-1-2019 at 17:42

What is the best way to concentrate it if you don't have vacuum distillation? I already have 50% solution but i want to concentrate it up to 70%

Felab - 18-1-2019 at 09:48

Quote: Originally posted by feedme94  
What is the best way to concentrate it if you don't have vacuum distillation? I already have 50% solution but i want to concentrate it up to 70%


Put it on a desiccator (an aquarium tank with a lid and a drying agent at the bottom will suffice) with H2SO4 or the drying agent of your choice. Keep mesauring density and decrease in volume until you get to the concentration you want (or it explodes). This could take you a month or so.

Please, use clean glasware and be very carefull!

CobaltChloride - 19-1-2019 at 06:33

If you do attempt Felab's procedure, please be careful as the highly concentrated H2O2 might explode and it is also very corrosive. I suggest taking the same precautions as the experimenter in this video does: https://www.youtube.com/watch?v=mvrObVmXTUU