Sciencemadness Discussion Board

Potassium permanganate storage

HydrogenSulphate - 18-10-2020 at 09:18

Hi fellow SciMad members,

I have in storage perfectly dry potassium permanganate in its original plastic (polythene, I suspect) bag packaging, unopened and totally dry. It has been kept in complete darkness. The material is fine grade (as opposed to coarse crystals). I have noticed that, where the crystals are in direct contact with the polythene, there is brown staining, which has to be manganese dioxide. It appears that the permanganate slowly reacts with certain plastics. Would it be a good idea to transfer the material to a glass Duran/Schott reagent bottle in order to avoid further decomposition and contamination of the material with manganese dioxide?

valeg96 - 18-10-2020 at 10:25

Glass containers are 9/10 times better. Plastic is chosen by suppliers because it's cheaper, lighter (cheaper to deliver!) and more durable should the product be slammed around. I would transfer it to a glass container along with the original label.

[Edited on 18-10-2020 by valeg96]

metalresearcher - 18-10-2020 at 11:42

I agree. I have KMnO4 in a glass jar since ten years and it is still intact.

Herr Haber - 18-10-2020 at 13:56

As a kid I found glass drink bottles in an old shed filled with KMnO4. Many of them were not even closed.
The crystals were huge. All of this was stored among other gardening supplies.

It worked so well on the city's fountains that we went back to collect as much as we could from the broken bottles :)

My own has now been for several years in a LDPE bottle and shows no sign of change.

chemist1243 - 18-10-2020 at 16:52

I ordered a few ounces of KMnO4 from loud wolf scientific around Christmas last year. It’s completely dry and at least 95% purity(they claim its higher, though). It’s stored in a polypropylene container and there’s no brown staining what so ever. None the less, transfer it to a glass bottle. Maybe i just haven’t let my KMnO4 sit long enough.

arkoma - 18-10-2020 at 20:30

Quote: Originally posted by chemist1243  
I ordered a few ounces of KMnO4 from loud wolf scientific around Christmas last year. It’s completely dry and at least 95% purity(they claim its higher, though). It’s stored in a polypropylene container and there’s no brown staining what so ever. None the less, transfer it to a glass bottle. Maybe i just haven’t let my KMnO4 sit long enough.



Had a bottle from same supplier for four years. No problems.

DavidJR - 19-10-2020 at 02:07

I've got mine stored in a plastic bottle (PE, I think) and there are no signs of brown staining on the bottle walls.

HydrogenSulphate - 25-10-2020 at 16:42

Thanks for your inputs. I have transferred the material to a glass GL45 Simax reagent bottle. The original container was a flexible polythene pouch, which shows brown staining on the inner surface where the permanganate reacted with it. The permanganate was bought from a garden supply store (it is used for disinfecting and algae control). I assume that it is technical grade. Hopefully pure enough for most reactions. The crystals are small-grained and dull black- not shiny and lustrous.

[Edited on 26-10-2020 by HydrogenSulphate]

aromaticfanatic - 26-11-2020 at 15:07

Quote: Originally posted by arkoma  
Quote: Originally posted by chemist1243  
I ordered a few ounces of KMnO4 from loud wolf scientific around Christmas last year. It’s completely dry and at least 95% purity(they claim its higher, though). It’s stored in a polypropylene container and there’s no brown staining what so ever. None the less, transfer it to a glass bottle. Maybe i just haven’t let my KMnO4 sit long enough.



Had a bottle from same supplier for four years. No problems.


Good to know. I bought some from the same supplier. Good so far to my knowledge.

TriiodideFrog - 26-11-2020 at 18:14

I keep my KMnO4 in a cheap glass bottle and store in a cool, dry, well-ventilated location, away from flammables, combustibles, and other reducing agents.

Fery - 26-11-2020 at 23:25

I store it always in plastic for decades and bottom shelf. Bad situation could occur if stored in glass, falls to the ground and breaks together with glass bottle of glycerin.

aromaticfanatic - 26-11-2020 at 23:54

Quote: Originally posted by Fery  
I store it always in plastic for decades and bottom shelf. Bad situation could occur if stored in glass, falls to the ground and breaks together with glass bottle of glycerin.


That's why you don't store incompatible chemicals (fuel and oxidizers) in the same area.