Sciencemadness Discussion Board - Isopropyl Alcohol (2-propanol) Peroxides

Isopropyl Alcohol (2-propanol) Peroxides

maxpayne - 15-11-2011 at 12:16

Hello.

I have a concern with peroxides forming alcohol, 2-propanol. I read that upon standing in a closed bottle, 2-propanol can form explosive peroxides. It is especially noted that upon concentration or unintended evaporation it is very likely that will form peroxides. Of course this is only for pure >99% alcohol.

Now, I have a bottle at least 4 years old of 2-propanol >99% which I have forgotten until now (90% full 1 liter bottle). I want to open the bottle and use this alcohol. Is it possible that peroxides have formed around cap screw or to put it simple, is it safe to open this bottle and use the alcohol?

Here are links to texts that i read:
http://www.bnl.gov/esh/shsd/programs/Program_Area_Chemicals_...

and here:
http://www.sigmaaldrich.com/chemistry/solvents/learning-cent...

[Edited on 15-11-2011 by maxpayne]

maxpayne - 16-11-2011 at 09:54

I just received an answer to my question from a pro, and also want to share this valuable information with you (personal info removed):

Dear Mr. V....

Thank you for contacting the Canadian Centre for Occupational Health and Safety with your recent inquiry. Isopropyl alcohol does form peroxides on standing. It can form peroxides when the anhydrous (no water) material is stored for long periods in contact with air and light. The peroxides are not hazardous unless concentrated by distillation. A number of explosions have been reported, which occurred during distillation of isopropyl alcohol following prolonged storage (4 years and longer). The explosions were caused by the presence of peroxides which had become concentrated in the distillation residue. Storage of the alcohol for over-long periods, often under poor conditions, is a common feature of the incidents. Also, the presence of 0.36M peroxide has been reported in a 99.5% pure sample of isopropyl alcohol stored for several months in a partially full clear glass bottle in strong daylight. The reformation of peroxides in de-peroxided isopropyl alcohol within a few days was reported.

The question is where was the bottle stored? Was it stored in the dark and how much air was in the bottle? What type of cap was on the bottle? Screw caps can cause a problem if some of the alcohol with peroxide collected on the cap. If the peroxide was dry, the opening of the screw cap can cause some friction and the peroxide can explode. It will probably be fine to open it bearing in mind what I just wrote, and dilute with water. It is also advisable to open the bottle in a fume hood, preferably behind a glass screen.

However, for safety reasons, if the bottle is 3-4 years old, with unknown amounts of peroxide present, it would be prudent not to use it, but to dispose of it unopened as hazardous waste. The rule is not to open and use bottles containing unknown amounts of peroxides that that have been standing around for more than 1 year. I don’t know what the regulations are in your country concerning disposal of hazardous waste. Certainly not to pour down the drain. If isopropyl alcohol is needed for an experiment, it is better to acquire a fresh bottle of the alcohol and store it in the dark.

If the bottle of isopropyl alcohol has been stored in the dark for the long period in the absence of air then it should be safe to open it. However, the bottle had been opened once and so there was air in the bottle. Under no circumstances should the alcohol be heated or distilled.

The alcohol can be tested for peroxides. Also there are procedures to remove the peroxides. The alcohol can be purified by passage through alumina. When peroxides are removed from solvents by chromatographic adsorption on alumina columns, the concentrated band of strongly adsorbed peroxides at the top of the column may become hazardous if the solvent evaporates. Alternative methods of removing peroxides are to use acidified aqueous ferrous sulfate or aqueous potassium iodide.

I trust you will find this information helpful. If you have additional questions after you read this material or if you require more information, please don’t hesitate to contact the Inquiries Service at 1-800-668-4284.

Kind Regards,

E... A......

Occupational Health and Safety Specialist | Spécialiste de santé et sécurité au travail
Inquiries and Client Services | Demandes de renseignements et services à la clientèle
Canadian Centre for Occupational Health and Safety | Centre canadien d'hygiène et de sécurité au travail
135 Hunter St E | 135 rue Hunter est
Hamilton, ON Canada L8N 1M5
emma.ashurst@ccohs.ca
Telephone |Téléphone 905-572-2981 x4487 Facsimile |Télécopieur 905-572-4500
www.ccohs.ca | www.cchst.ca
Government of Canada | Gouvernement du Canada

[Edited on 16-11-2011 by maxpayne]

Explosive Isopropyl Alcohol

ScienceHideout - 16-9-2012 at 16:42

Just a Big Warning!

I've never heard anyone talk about this before, nor is it printed on the labels of the isopropyl alcohol bottles...

Is it coincidental that isopropyl alcohol is a secondary alcohol- and quite a few other secondary alcohols (sec butanol comes to mind) form peroxides?

I was reading a paper today and saw that once a school was distilling isopropyl alcohol and it exploded, injuring students. As it turns out, 2-propanol explodes on concentration...

If you've done it before (alas, I have... thank God I am alive) don't do it again. 99% isopropanol is available not only at Meijer but also at many computer stores. Although it is great to teach and learn about distillation, it is not worth it and there are many other chemicals that would work and are safer.

Distilling isopropanol is a common rookie mistake that should be eliminated. We should prevent it.

Dr.Bob - 16-9-2012 at 17:08

I was originally quite skeptical of this post, but after searching, but there are actually real articles on this. I would say that the dangers of 2-propanol can't be too high, based on the lack of actual accidents I could find, compared to THF and diethyl ether, but that could be because so few people normally distill 2-propanol, and it normally has some water in it, which reduces peroxide formation in most cases. So it might be wise to not distill it to dryness or to simply test it for peroxides if it is old. We have certainly seen that happen in old bottles of THF and diethyl ether, never tried testing isopropanol before.

http://www.sigmaaldrich.com/chemistry/solvents/learning-cent...

Hexavalent - 16-9-2012 at 22:44

This is precisely why I only buy my iPrOH from lab suppliers, at 99% concentration. If I need better, I simply just dry it with anhydrous salts and hope for the best.

99chemicals - 17-9-2012 at 05:46

Somebody should tell that to this guy:

https://www.youtube.com/watch?v=2u1EK0vAPwY

maxpayne - 17-9-2012 at 09:49

I already started thread about this some time ago:

Here is the link:

http://www.sciencemadness.org/whisper/viewthread.php?tid=180...

I still did not opened that bottle

but I do not think that peroxides can form on the cap. It is only dangerous on concentration (distillation, evaporation)

kristofvagyok - 17-9-2012 at 10:13

Isoproanol forms peroxides? What? Never ever heard from that. Test it with tianyl-sulfate.

Also, I have had a project with choline derivatives what was a bit impure so I have to recrystallize it. I have used isopropanol/acetone mixture and I have found a circa 50 year old bottle of iPA in the lab. It was perfect. I also redistilled the solvents to use them again... An wolala, I haven't exploded.

In the paper where they described this explosion how did they distilled it? On atmospheric pressure? Vacuum? Did they used flame or a hotplate?

maxpayne - 17-9-2012 at 10:24

kristofvagyok,

It seems that all this story about peroxide forming is not 100% guaranteed. I remember that I read somewhere, 16 solvents that are susceptible to form peroxides on contact with air, diethyl ether won first place, and our IPA was last, 16. place. So, there is no defined condition when, if at all, peroxides will form.

We just need to test it for peroxides before use, that is all what is needed for safety.

mr.crow - 17-9-2012 at 11:21

This thread is a huge over-reaction

Hexavalent - 17-9-2012 at 11:53

Quote: Originally posted by mr.crow

This thread is a huge over-reaction

Not for the school mentioned in the OP.

ScienceHideout - 17-9-2012 at 11:55

Well we all know that secondary alchohols form peroxides- like sec-Butanol, or 2-octanol (doesn't pentan-2-ol form peroxides, too?).

That being said, this thread isn't an over reaction- it is dictated simply by common sense... although we often forget to think about this type of thing twice because of how innocuous iPrOH usually seems.

Here We are...

ScienceHideout - 17-9-2012 at 12:03

Excuse my double post...
The following chems form peroxides:
I put an asterisk near any sec alcohols, and I put two asterisks next to anything that the home chemist might have lying around.

Table A--Chemicals that form explosive levels of peroxides without concentration.
Butadinea
Isopropyl ether
Sodium amide (sodamide)
Chloroprenea
Potassium amide
Tetrafluoroethylenea
Divinylacetylene
**Potassium metal
Vinylidene chloride

Table B--Chemicals that form explosive levels of peroxides upon concentration
Acetal
**Diethyl ether
2-Pentanol
**Acetaldehyde
Diethylene glycol dimethyl ether (diglyme)
4-Penten-1-ol
**Benzyl alcohol
**Dioxanes
1-Phenylethanol
*,**2-Butanol
Ethylene glycol dimethyl ether (glyme)
2-Phenylethanol
Cumene
4-Heptanol
*,**2-Propanol
**Cyclohexanol
*2-Hexanol
**Tetrahydrofuran
2-Cyclohexen-1-ol
Methylacetylene
Tetrahydronaphthalene
Cyclohexene
3-Methyl-1-butanol
Vinyl ethers
Decahydronaphthalene
Methylcyclopentane
*Other secondary alcohols
Diacetylene
Methyl isobutyl ketone
Dicyclopentadiene
4-Methyl-2-pentanol

*******************Access to the full list is here: http://safety.dri.edu/Hazards/PeroxideFormingCompounds.pdf

[Edited on 17-9-2012 by ScienceHideout]

S.C. Wack - 17-9-2012 at 12:13

http://pubs.acs.org/doi/abs/10.1021/ja01264a512
Explosions have been noted since this.

mr.crow - 20-9-2012 at 06:50

Thanks for the article, interesting

The usual precautions of storing in the dark with amber bottles and not distilling to dryness seem sufficient.

Saying no one should do this ever is a bit much. Its a very easy and useful thing to do. Risks also include the flask cracking, falling off, being knocked over, spills, etc

How about adding some sort of reducing agent before distilling? Like FeCl2

feacetech - 20-9-2012 at 13:43

This got me thinking I noticed a bottle of IPA in a clearglass bottle 2.5 L with a handle, half full.

I had been on the shelf for some time (~ 6 - 12 month) and is used for wetting hydrophobic filters

it tested positive for peroxide (0.1 g of KI in 1 mL of GAA mixed with 1 mL IPA turned dark brown, 1 mL of 10% KI in 10 mL of IPA developed for 10mins yielded a yellow colour)

So I tested the source, a 25 L drum in a flammable goods storgae cupboard this was about half full but has been kept with the lid on in the dark in a realitivly cold climate, I am un sure of its age but at a guess its not new :p

It tested positive for peroxide aswell with the same intesity yellow as the clear bottle (1 mL of 10% KI in 10 mL of IPA for 10mins in the dark)

For the what the IPA is used for I belive the risk is next to none.

However I have trasfered the aliquot from the clear glass into an amber bottle

I had never thought of IPA forming organic peroxides, but was aware that all orgaincs should be kept in amber glass and am glad I read this thread incase I had ever tried to distill it to dryness. Although its probly a low chance of explosion.

Next time I get a drum/bottle of IPA I think I wll check it upon receipt.

[Edited on 20-9-2012 by feacetech]

subsecret - 10-7-2013 at 15:21

This is pretty exciting. Just about half an hour ago I distilled about 250 ml of 2-propanol after drying it with magnesium sulfate. When I took a small whiff of the flask, it didn't smell quite like 2-propanol. During the distillation, however, I noticed that after the 2-propanol had boiled off at about 85 C, I observed another defined boiling point at about 95 C. This could be due to the fact that I had inserted my thermometer past the immersion line, but I'm not sure. A good half of the solution boiled at this elevated temperature. I just disposed of the solution without any problems.

If this higher-boiling material was a peroxide of 2-propanol, I could've easily hurt myself. I'm not familiar with the sensitivity of these materials, but I assume that they're pretty dangerous. Being informed is the best way to prevent accidents, so be sure to do your research before you do an experiment. I'm thankful that I escaped unscathed.

[Edited on 10-7-2013 by Awesomeness]

[Edited on 11-7-2013 by Awesomeness]

AndersHoveland - 10-7-2013 at 15:26

That isopropanol could be peroxidated in storage is not too surprising. That alpha hydrogen atom is fairly easy to oxidize, and isopropyl alcohol is much more easily oxidized (initially to acetone) than ethanol or methanol.

I am assuming that acetone peroxide forms, or at least monomer fragments in the solution, consisting of the hydroperoxide. (CH3)2C(OH)(OOH)

I wonder if there is some way to intentionally promote the peroxidation of isopropyl alcohol. Perhaps continuously bubbling in air and exposing it to sunlight? Then hydrolyze it with dilute acid (to hydrolyze the peroxide) and recover the H2O2. It could be an amateur route to making H2O2, though not very practical.

[Edited on 10-7-2013 by AndersHoveland]

kristofvagyok - 10-7-2013 at 21:27

This is such a popular thread and it is about something that almost never happen...

Today afternoon I will start an experiment with 100cm3 iPrOH , 1cm3 35% H2O2 and a little catalyst, maybe sulfuric acid. Since a lot of you are frightened from the peroxide of the propanol. One month standing on the shelf and I will distill it to see what will happen. I will report if anything interesting happens.

AndersHoveland - 10-7-2013 at 21:40

Quote: Originally posted by kristofvagyok

Today afternoon I will start an experiment with 100cm3 iPrOH , 1cm3 35% H2O2 and a little catalyst, maybe sulfuric acid.

That may likely not do anything. Perhaps you do not understand the chemistry behind this. It is not the same as mixing acetone and H2O2.

The isopropanol is not a ketone, so H2O2 would not be able to condense with it. Although, if the H2O2 managed to oxidize the isopropanol to acetone, then it could condense with more H2O2.

I am not sure exactly how vulnerable isopropanol is to oxidation, under what specific reaction conditions, but I suspect it can be slowly oxidized by O2 in the presence of sunlight.

For your experiment, I strongly recommend continuously passing oxygen into it, or at least having it well aerated, and exposure to sunlight (or fluorescent) as well.

AndersHoveland - 28-7-2013 at 04:07

I did find this:

Quote:

"Evaporating hydrogen peroxide solution in diethyl ether gives rise to a residue that detonates when it comes into contact with a glass stirrer or a platinum spatula."

Chemical Risk Analysis: A Practical Handbook, Bernard Martel

S.C. Wack - 28-7-2013 at 11:09

Quote: Originally posted by AndersHoveland

I did find this:

Quote:

"Evaporating hydrogen peroxide solution in diethyl ether gives rise to a residue that detonates

So? Were you planning on reproducing this? It is the reproduction I approve of for many of our newer members...

Bretherick's:
Several explosions have occurred during laboratory distillation of isopropanol
Renfrew, M. M., J. Chem. Educ., 1983, 60(9), A229
Bonafede, J. D., J. Chem. Educ., 1984, 61, 632
Mirafzal, G. A. et al., J. Chem. Educ., 1988, 65(9), A226—229
Bohanon, J. T., Chem. Eng. News, 1989, 67(1), 4

[Edited on 28-7-2013 by S.C. Wack]

Mush - 28-10-2019 at 13:32

Quote: Originally posted by S.C. Wack

Quote: Originally posted by AndersHoveland

I did find this:

Quote:

"Evaporating hydrogen peroxide solution in diethyl ether gives rise to a residue that detonates

Great find! Thanx for it!

Everyone who uses IPA should be aware of this danger. IPA is a very common solvent.

Bretherick's Handbook of Reactive Chemical Hazards, 7th Edition.
Academic Press, 2006, page 509.

1, Renfrew, M. M., J. Chem. Educ., 1983, 60(9), A229
2, Bonafede, J. D., J. Chem. Educ., 1984, 61, 632
3, Redemann, C. E., J. Amer. Chem Soc, 1942, 64, 3049
4, Mirafzal, G. A. et al., J. Chem. Educ., 1988, 65(9), A226—229
5, Bohanon, J. T., Chem. Eng. News, 1989, 67(1), 4

Several explosions have occurred during laboratory distillation of isopropanol[1,2,4,5], some with a sample stored for 5 years in a part empty can [5], No cause was apparent, but presence of traces of ketone(s) promoting peroxidation is a probability. Previously, the presence of 0.36M peroxide had been reported in a 99.5% pure sample of isopropanol stored for several months in a partially full clear glass bottle in strong daylight [3]. The reformation of peroxides in de-peroxided isopropanol "within a few days' had been noted [2]. It appears that the tertiary H on the 2-position is susceptible to autoxidation, and that 2-propanol must be classed as peroxidisable.2-Hydroperoxy-2-hydroxypropane has, in fact, been isolated from photocatalysed
oxidation of isopropanol.

See 2-Butanone, below
See also Oxygen (Gas): Alcohols
See peroxidisable compounds (reference 7)

2-Hydroperoxy-2-hydroxypropane

Preparative Organic Photochemistry (Springer, 1968)
Alexander Schönberg
page 379

c) Photosensitized oxidation of secondary alcohols

When secondary alcohols are irradiated under oxygen in the presence of
dehydrogenating sensitizers, e.g. benzophenone, a radical chain reaction is initiated leading to alkyl hydroperoxides carrying the OOH function at the same carbon atom as the hydroxy group [37]. For instance, 2-hydroperoxy-2-hydroxypropane (38), 2-hydroperoxy-2-hydroxybutane (39) and 2-hydroperoxy-2-hydroxypentane (40) are obtained by this method.

2-Hydroperoxy-2-hydroxypropane (38) [37], 78 g isopropanol, in which 1.5 gbenzophenone were dissolved, were irradiated with a Philips HPK 125 W mercury burner in an apparatus incorporating a water-cooled glass shaft for immersing the lamp. Oxygen, which was passed through a calcium chloride drying tower, was circulated entering the
solution through a fritted glass gas inlet. 3.9 l O2 were absorbed in 17.7 hrs. (12°), the reactants adopting a light yellow color during the irradiation. An aliquot of the solution was analyzed: 82% of the oxygen consumed titrated for active oxygen, and acetone 2,4- dinitrophenylhydrazone precipitated in 92% yield. The irradiated solution was concentrated at room temperature/0.1 mm Hg and the residue distilled at 0.01 mm Hg (bath temperature 20—25°) when 0.6 g bis-(2-hydroperoxy-2-propyl) peroxide (41), m.p. 37°, crystallized in the condenser. 4 g 38 (25% based on 02 consumed) was obtained as "distillate". The hydroperoxide is explosive, and the experiment should therefore be carried out with the utmost caution (explosion screen, use of water bath only I).

[Edited on 28-10-2019 by Mush]

2-Hydroperoxy-2-hydroxypropane.jpg - 16kB

SWIM - 28-10-2019 at 14:16

Quote: Originally posted by subsecret

This is pretty exciting. Just about half an hour ago I distilled about 250 ml of 2-propanol after drying it with magnesium sulfate. When I took a small whiff of the flask, it didn't smell quite like 2-propanol. During the distillation, however, I noticed that after the 2-propanol had boiled off at about 85 C, I observed another defined boiling point at about 95 C. This could be due to the fact that I had inserted my thermometer past the immersion line, but I'm not sure. A good half of the solution boiled at this elevated temperature. I just disposed of the solution without any problems.

If this higher-boiling material was a peroxide of 2-propanol, I could've easily hurt myself. I'm not familiar with the sensitivity of these materials, but I assume that they're pretty dangerous. Being informed is the best way to prevent accidents, so be sure to do your research before you do an experiment. I'm thankful that I escaped unscathed.

[Edited on 10-7-2013 by Awesomeness]

[Edited on 11-7-2013 by Awesomeness]

I was just reading about this peroxide because of another related thread.
Boiling point estimates for this compound run around 90C, so it could well be what you distilled.

It's amazing what can be distilled with a little luck. I read once of somebody distilling nitroglycerine at atmospheric pressure.
Mostly it just decomposed from the heat, but it didn't explode. (This was done behind a blast shield in some sort of a real lab somewhere, not in some crazy guy's basement)

Schmiddy - 8-11-2019 at 16:05

This thread has solved a mystery of why my evaporating dish exploded.

While evaping some iso extracted resin with low heat my evaporating dish exploded with a noticeable sound,not just the distinct chink or psht of glass breaking but the sound like a firecracker.

the iso I was using was old,used,abused and improperly stored in a clear bottle,in direct sunlight in a south facing window(northern hemsiphere)

The only explanation I have is that accumulated peroxides are the culprit.

I had been warned to always use fresh iso and not to recycle iso for extractions by old timers.
I was also advised to store unused iso in a cool and dark place in full bottles.

I was standing 18" from the pyrex dish which measured 9x13" when it exploded. I was uninjured but sticky and had 3 hours of cleaning up a thousand pieces of sticky glass.

Not fun.

[Edited on 9-11-2019 by Schmiddy]

chloric1 - 6-10-2024 at 18:09

Wow! I was actually in the middle of distilling 99% isopropyl alcohol that is roughly 3 years old. I had distilled roughly 250ml without incident I browsed and found this! The only reason I was distilling isopropyl was because it was cloudy with what I presume is denatonium benzoate. I did not want to burn the impurities into my new round bottom flask so I was never planning on distilling to dryness. I am not sure when distilling to dryness is ever a good idea. Anyways, after this thread I made a strong ferrous sulfate solution acidified with sulfuric acid. I added it to the remaining 250 that I was about to distill and stirred.

When I applied heat the ferrous sulfate started to produce bubbles at 35 Celsius similar like hydrogen peroxide decomposition

. Judging about what I saw any peroxide that was present was pretty dilute as definitely less than 1%. The temperature then rapidly rose to 80 Celsius and water clear isopropyl alcohol came over 2 drops a second. The ferrous sulfate precipitated to the bottom and it became more a grey green color. I stopped distillation when I received 250 ml of clear distillate. I discarded roughly 100 ml of fluid into fire pit for incineration. Although initially I saw some peroxide action, nothing suggested that such a hazard exists. Maybe a preliminary heating with acid ferrous sulfate then distillation is feasible. But then again 99 % isopropyl alcohol is cheap and widely available. I just had cloudy alcohol that I wanted clear for solvent dyes.

Gualterio_Malatesta - 31-10-2024 at 02:10

A "wow!" from me also - first time hearing that IPA forms peroxides, big surprise for me!
So I went and got meself peroxide test strips and tested my IPA. I got two dark glass bottles of IPA from 2010 and 2011 stored all these years in a dark place at rt. One of them was 2/3 full.
Both tested negative.