maxpayne
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Isopropyl Alcohol (2-propanol) Peroxides
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]
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maxpayne
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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]
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ScienceHideout
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Explosive Isopropyl Alcohol
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.
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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Dr.Bob
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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...
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Hexavalent
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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.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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99chemicals
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Somebody should tell that to this guy:
https://www.youtube.com/watch?v=2u1EK0vAPwY
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maxpayne
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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)
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kristofvagyok
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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?
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
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maxpayne
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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.
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mr.crow
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This thread is a huge over-reaction
Double, double toil and trouble; Fire burn, and caldron bubble
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Hexavalent
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Not for the school mentioned in the OP.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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ScienceHideout
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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.
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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ScienceHideout
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Here We are...
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]
hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!
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S.C. Wack
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http://pubs.acs.org/doi/abs/10.1021/ja01264a512
Explosions have been noted since this.
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mr.crow
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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
Double, double toil and trouble; Fire burn, and caldron bubble
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feacetech
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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]
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subsecret
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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.![:o](./images/smilies/shocked.gif)
[Edited on 10-7-2013 by Awesomeness]
[Edited on 11-7-2013 by Awesomeness]
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AndersHoveland
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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]
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bfesser
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Threads Merged 10-7-2013 at 16:27 |
bfesser
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Thread Moved 10-7-2013 at 16:28 |
kristofvagyok
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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.
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
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AndersHoveland
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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.
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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AndersHoveland
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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 |
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S.C. Wack
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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]
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Mush
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Quote: Originally posted by S.C. Wack ![](images/xpblue/lastpost.gif) |
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] |
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]
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SWIM
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Quote: Originally posted by subsecret ![](images/xpblue/lastpost.gif) | 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.![:o](./images/smilies/shocked.gif)
[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)
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Schmiddy
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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]
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