Potassium permanganate is aninorganic compound with thechemical formula KMnO4. It is a purplish-black crystalline salt, which dissolves in water asK+ andMnO− 4 ions to give an intensely pink to purple solution.
It is also referred to as chameleon mineral, Condy's crystals, permanganate of potash, hypermangan, purple potion powder, permanganic acid (potassium salt),[1] and purple salt.[1]
KMnO4 formsorthorhombic crystals with constants:a = 910.5 pm,b = 572.0 pm,c = 742.5 pm. The overall motif is similar to that forbarium sulfate, with which it formssolid solutions.[7] In the solid (as in solution), eachMnO−4 centre is tetrahedral. The Mn–O distances are 1.62 Å.[8]
The purplish-black color of solid potassium permanganate, and the intensely pink to purple color of its solutions, is caused by its permanganate anion, which gets its color from a strongcharge-transfer absorption band caused by excitation of electrons from oxo ligand orbitals to empty orbitals of the manganese(VII) center.[9] The crystal form can range from purple to black or gray, and has a blue metallic sheen.[1]
Potassium permanganate is no longer the preferred treatment for dermatological conditions[10] and no form of it is labeled for human use by theUS Food and Drug Administration.[12] It should never be taken internally, because it is highly toxic and corrosive tomucous membranes and skin.[13][14][10][15][1]
Potassium Permanganate, U.S.P., has a limited topical efficacy against bacteria and fungi. Concentrations of 1:5000 or more are necessary for an effective bactericidal action, but they are irritating to tissues. Consequently, solutions of 1: 10,000 are usually used. However, up to an hour may be required to kill many bacteria, and some strains survive exposure to this concentration. For this reason, permanganate has been made obsolete by much superior antiseptic and antifungal drugs.
Traditionally potassium permanganate was prescribed for a number ofskin conditions, includingfungal infections of the foot,impetigo,pemphigus, superficial wounds,dermatitis, and topical ulcers.[16][17][1]Radioactive contamination of the skin could be cleaned with potassium permanganate[1] and vigorous scrubbing. For topical ulcers it was used together withprocaine benzylpenicillin.[17] Typically it was used in skin conditions that produce a lot of liquid.[16] It could be applied as a soaked dressing or a bath.[17] Petroleum jelly may be used on the nails before soaking to prevent their discoloration.[18] For treating eczema, it was recommended using for only a few days at a time due to irritating the skin.[19]
Potassium permanganate was first made in the 1600s and came into common medical use at least as early as the 1800s.[20] DuringWorld War I Canadian soldiers were given potassium permanganate (to be applied mixed with an ointment) in an effort to preventsexually transmitted infections.[21] Some have attempted to bring about anabortion by putting it in the vagina, though this is not effective.[22][23][14] Other historical uses have included an effort to wash out the stomach in those withstrychnine orpicrotoxin poisoning.[24]
Side effects fromtopical use include irritation of the skin and discoloration of clothing.[17] A harsh burn on a child from an undissolved tablet has been reported.[19] Higher concentration solutions can result inchemical burns.[15] Therefore, in 2015 theBritish National Formulary recommended 100 mg be dissolved in a liter of water before use to form a 1:10,000 (0.01%) solution.[19][25][17] Wrapping the dressings soaked with potassium permanganate is not recommended.[citation needed]
Potassium permanganate istoxic if taken by mouth.[13][1] Concentrated solutions when drunk have resulted inacute respiratory distress syndrome or swelling of the airway.[26] Effects may includenausea,vomiting, andshortness of breath.[27] If a sufficiently large amount (about 10 grams) is eaten death may occur.[27] Concentrated solutions of potassium permanganate and repeated exposure cause skin corrosion anddermatitis.[1]
Recommended measures for those who have ingested potassium permanganate includegastroscopy.[26]Activated charcoal or medications to cause vomiting are not recommended. While medications likeranitidine andacetylcysteine may be used in toxicity, evidence for this use is poor.[26]
In the United States the FDA requires tablets of the medication to be sold byprescription.[14] Potassium permanganate, however, does not have FDA approved uses[12] and therefore non medical grade potassium permanganate is sometimes used for medical purposes.[citation needed]
It is available under a number ofbrand names including Permasol, Koi Med Tricho-Ex, and Kalii permanganas RFF.[28] It is occasionally called "Condy's crystals".[29]
Almost all applications of potassium permanganate exploit itsoxidizing properties.[31] As a strong oxidant that does not generate toxic byproducts, KMnO4 has many niche uses.[citation needed]
Potassium permanganate colors the water purple and neutralizesrotenone treatment inSoda Butte Creek.
Potassium permanganate is used extensively in the water treatment industry.[32] It is used to removeiron[33] andhydrogen sulfide (rotten egg smell) fromwell water via a "manganese greensand" filter.[citation needed] "Pot-Perm" is also obtainable atpool supply stores and is used additionally to treat wastewater.[citation needed] Historically it was used to disinfect drinking water,[34][35] though the EPA considers it a poor disinfectant.[36] It can turn water afuchsia or pink color.[37][35][38] Modern hiking and survivalist guides advise against using potassium permanganate in the field because it is difficult to dose correctly.[39]
Potassium permanganate is not FDA approved for use with food fish in the United States, however it is categorized under "regulatory action deferred" and is legal to use because the FDA considers it "low regulatory priority" and at low risk for adverse human health effects.[12][40][41]
Potassium permanganate is a treatment forIchthyophthirius multifiliis (commonly known as "ich") andprotozoa (such asTrichodina), which infect and usually kill freshwater aquarium fish.[42] A minimum dose of 2ppm is required. Water with more organic load and a higher number of organisms includingalgae requires more permanganate. High concentrations and use more than once per week kill fish. Food fish require a 7-day period after treatment before they can be consumed.[43][12]
An alternative application is in the control of nuisance organisms such aszebra mussels[32] in freshwater collection and treatment systems.[citation needed]
Rotenone can be deactivated in water with the use of potassium permanganate to lower toxicity to acceptable levels. A 1:1 ratio of permanganate to rotenone is insufficient to deactivate rotenone in most situations.[44]
KMnO4 is used inqualitative organic analysis to test for the presence ofunsaturation. It is sometimes referred to asBaeyer's reagent after the German organic chemistAdolf von Baeyer. The reagent is an alkaline solution of potassium permanganate. Reaction with double or triple bonds (R2C=CR2 orR−C≡C−R) causes the color to fade from purplish-pink to brown.Aldehydes andformic acid (andformates) also give a positive test.[46] The test is antiquated.
Baeyer's reagent reaction
KMnO4 solution is a commonthin layer chromatography (TLC) stain for the detection of oxidizable functional groups, such as alcohols, aldehydes, alkenes, and ketones. Such compounds result in a white to orange spot on TLC plates.[47][48][49]
Potassium permanganate can be used to quantitatively determine the total oxidizable organic material in an aqueous sample. The value determined is known as thepermanganate value. Inanalytical chemistry, a standardizedaqueous solution of KMnO4 is sometimes used as an oxidizingtitrant forredox titrations (permanganometry). As potassium permanganate is titrated, the solution becomes a light shade of purple, which darkens as excess of the titrant is added to the solution. In a related way, it is used as areagent to determine theKappa number of wood pulp. For the standardization of KMnO4 solutions, reduction byoxalic acid is often used.[50] In agricultural chemistry, it is used for estimation of activecarbon in soil.[51]
Aqueous, acidic solutions of KMnO4 are used to collect gaseousmercury in flue gas during stationary source emissions testing.[52]
Inhistology, potassium permanganate was used as a bleaching agent.[53][54]
Ethylene absorbents extend storage time ofbananas even at high temperatures. This effect can be exploited by packing bananas inpolyethylene together with potassium permanganate. By removing ethylene by oxidation, the permanganate delays the ripening, increasing the fruit's shelf life up to 4 weeks without the need for refrigeration.[55][56][57]
Potassium permanganate is sometimes included in survival kits: as ahypergolic fire starter (when mixed withglycerol antifreeze from a car radiator);[59][60][61] as a water sterilizer; and for creating distress signals on snow.[62] Modern hiking and survivalist guides advise against using potassium permanganate in the field because it is difficult to dose correctly.[39]
Potassium permanganate is added to "plastic sphere dispensers" to create backfires, burnouts, andcontrolled burns. Polymer spheres resemblingping-pong balls containing small amounts of permanganate are injected withethylene glycol and projected towards the area where ignition is desired, where they spontaneously ignite seconds later.[63][64] Both handheld[64] helicopter-[63] unmanned aircraft systems (UAS) or boat-mounted[64] plastic sphere dispensers are used.
Potassium permanganate is one of the principal chemicals used in the film and television industries to "age" props and set dressings. Its ready conversion to brownMnO2 creates "hundred-year-old" or "ancient" looks onhessian cloth (burlap), ropes, timber and glass.[65][non-primary source needed]
Potassium permanganate is used as anoxidizing agent in the synthesis ofcocaine andmethcathinone.[66] It can purifycocaine paste with oxidization to increase its stability. This led to theDrug Enforcement Administration launching Operation Purple in 2000, with the goal of monitoring the world supply of potassium permanganate; however, potassium permanganate derivatives and substitutes were soon used thereafter to avoid the operation.[67]
Treating a well with potassium permanganate in India (1949).
In 1659,Johann Rudolf Glauber fused a mixture of the mineralpyrolusite (manganese dioxide, MnO2) andpotassium carbonate to obtain a material that, when dissolved in water, gave a green solution (potassium manganate) which slowly shifted to violet and then finally red.[68][69][70] The reaction that produced the color changes that Glauber observed in his solution of potassium permanganate and potassium manganate (K2MnO4) is now known as the "chemical chameleon".[71]
The case of the chameleon mineral alludes to a broader reflection on how epistemological framework dictates what early modern scientists perceived as meaningful discoveries.[72] Little literature exists on Glauber’s accidental discovery of potassium permanganate and the importance of both its dismissal and its conversion into a modern medical and hygienic staple.
The earliest description of the production of potassium permanganate is here.[73] Just under 200 years later, London chemistHenry Bollmann Condy had an interest in disinfectants; he found that fusing pyrolusite withsodium hydroxide (NaOH) and dissolving it in water produced a solution with disinfectant properties. He patented this solution, and marketed it as 'Condy's Fluid'. Although effective, the solution was not very stable. This was overcome by usingpotassium hydroxide (KOH) rather than NaOH. This was more stable, and had the advantage of easy conversion to the equally effective potassium permanganate crystals. This crystalline material was known as 'Condy's crystals' or 'Condy's powder'. Potassium permanganate was comparatively easy to manufacture, so Condy was subsequently forced to spend considerable time in litigation to stop competitors from marketing similar products.[74] According toVarlam Shalamov, potassium permanganate solution was used as a catch-all treatment for dysentery, frostbite and ulcers in the Gulag camps of Kolyma.
Early photographers used it as a component offlash powder. It is now replaced with other oxidizers, due to the instability of permanganate mixtures.[citation needed]
With sodium hydroxide, the end product is notsodium manganate but a Mn(V) compound, which is one reason why the potassium permanganate is more commonly used thansodium permanganate. Furthermore, the potassium salt crystallizes better.[31]
The potassium manganate is then converted into permanganate byelectrolytic oxidation in alkaline media:
Although of no commercial importance, potassium manganate can be oxidized bychlorine or bydisproportionation under acidic conditions.[75] The chlorine oxidation reaction is
2 K2MnO4 + Cl2 → 2 KMnO4 + 2 KCl
and the acid-induced disproportionation reaction may be written as
3 K2MnO4 + 4 HCl → 2 KMnO4 + MnO2 + 2 H2O + 4 KCl
A weak acid such ascarbonic acid is sufficient for this reaction:
3 K2MnO4 + 2 CO2 → 2 KMnO4 + 2 K2CO3 + MnO2
Permanganate salts may also be generated by treating a solution of Mn2+ ions with strong oxidants such aslead dioxide (PbO2),sodium bismuthate (NaBiO3), orperoxydisulfate.Tests for the presence of manganese exploit the vivid violet color of permanganate produced by these reagents.
Dilute solutions of KMnO4 convertalkenes intodiols. This behaviour is also used as aqualitativetest for the presence of double or triple bonds in a molecule, since the reaction decolorizes the initially purplepermanganate solution and generates a brown precipitate (MnO2). In this context, it is sometimes calledBaeyer's reagent. However,bromine serves better in measuring unsaturation (double or triple bonds) quantitatively, since KMnO4, being a very strongoxidizing agent, can react with a variety of groups.
Under acidic conditions, the alkene double bond is cleaved to give the appropriatecarboxylic acid:[76]
Glycols andpolyols are highly reactive toward KMnO4. For example, addition of potassium permanganate to an aqueous solution ofsugar andsodium hydroxide produces thechemical chameleon reaction, which involves dramatic color changes associated with the various oxidation states ofmanganese. A related vigorous reaction is exploited as a fire starter in survival kits. For example, a mixture of potassium permanganate andglycerol or pulverizedglucose ignites readily.[59] Its sterilizing properties are another reason for inclusion of KMnO4 in a survival kit.[citation needed]
Treating a mixture of aqueous potassium permanganate with aquaternary ammonium salt results in ion exchange, precipitating the quat salt of permanganate. Solutions of these salts are sometimes soluble in organic solvents:[79]
KMnO4 + R4NCl → R4NMnO4 + KCl
Similarly, addition of acrown ether also gives a lipophilic salt.[80]
This reaction illustrates the relatively rare role of hydroxide as a reducing agent.
Addition of concentrated sulfuric acid to potassium permanganate givesMn2O7.[82] Although no reaction may be apparent, the vapor over the mixture will ignite paper impregnated with alcohol. Potassium permanganate and sulfuric acid react to produce someozone, which has a high oxidizing power and rapidly oxidizes the alcohol, causing it to combust. As the reaction also produces explosive Mn2O7, this should only be attempted with great caution.[83][84]
Potassium permanganate poses risks as a strong[1]oxidizer.[85] Contact with skin can cause skin irritation, skin and mucous membrane corrosion,[1] and in some cases severe allergic reaction.[citation needed] It is poisonous to humans and animals, and ingestion may lead to respiratory failure.[26] It is incompatible with organic and readily oxidized materials and poses a violent reaction and explosion hazard. It is flammable during some chemical reactions and emits toxic fumes when burning.[1]
It can also result in discoloration and clothing stains.[86]
^Hocart R, Mathieu-Sicaud A (1945). "A stabilization factor in the polymorphism of ammonium nitrate".Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences [Weekly Reports of the Sessions of the Academy of Sciences] (in French).221:261–263.
^World Health Organization (2019).World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization.hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
^Brauer E, ed. (1963).Handbook of Preparative Inorganic Chemistry. New York: Academic Press.
^Palenik GJ (1967). "Crystal structure of potassium permanganate".Inorg. Chem.6 (3):503–507.doi:10.1021/ic50049a015.
^Miessler GL, Fischer PJ, Tarr DA (2014).Inorganic Chemistry (5th ed.). Pearson. p. 430.ISBN978-0321811059.
^ Written at Drugs Used in Skin Diseases > Antiseptic agents > Potassium permanganate.WHO Model Prescribing Information (in English and French). Geneva, Switzerland: WHO Medicines Publications and Documentation. 1997. pp. 92-93 (PDF pages 98-99).ISBN92-4-140106-0. NLM Classification 250. Archived fromthe original on July 6, 2009. Retrieved12 October 2017.
^abcdYanong RP, Francis-Floyd R, Petty BD (October 28, 2021)."Therapeutic Considerations in Aquaculture".Merck Veterinary Manual. RetrievedAugust 27, 2025.A few compounds, including copper sulfate and potassium permanganate, are not FDA approved but are legally available for limited use in food fish under the category "regulatory action deferred" pending further study.
^abc"CFR – Code of Federal Regulations Title 21".CDRH Super Search. U.S. Food and Drug Administration, Center for Devices and Radiological Health. April 1, 2002. Archived fromthe original on November 29, 2002. Retrieved11 October 2017.(a) There have been a number of reports in the medical literature of serious injuries to women resulting from the misuse of potassium permanganate in an effort to induce abortion. Reports from physicians who have treated such cases show that the injuries are commonly caused by introducing tablets or crystals of potassium permanganate into the vagina. Experience with these cases shows that such use of potassium permanganate is not effective in producing abortion, but that instead the drug produces serious and painful injury to the walls of the vagina, causing ulcers, massive hemorrhage, and infection. Such dangerous and useless employment of potassium permanganate is apparently encouraged among the misinformed by the mistaken idea that the vaginal bleeding caused by the corrosive action of the drug indicates a termination of pregnancy, which it does not.
^Stout M (2013)."Chapter 16".The Complete Idiot's Guide to Aquaponic Gardening. Penguin. p. 234.ISBN9781615643332.Archived from the original on 2017-01-16.
^Durborow, Mitchell & Crosby 1998, p. 4: "At the time of this writing, FDA has also given copper sulfate (CuSO 4) and potassium permanganate (KMnO4) deferred status, which means that these treatments may be used without legal prosecution, but they may lose deferred status if evidence is found of any danger to the human consumer."
^Glagovich N (2013)."Baeyer Test".Department of Chemistry and Biochemistry. Central Connecticut State University. Archived fromthe original on 24 January 2013. Retrieved9 May 2018.
^Picken MM (April 2010). "Amyloidosis-where are we now and where are we heading?".Archives of Pathology & Laboratory Medicine.134 (4):545–551.doi:10.5858/134.4.545.PMID20367306.
^Scott KJ, McGlasson WB, Roberts EA (1970). "Potassium Permanganate as an Ethylene Absorbent in Polyethylene Bags to Delay the Ripening of Bananas During Storage".Australian Journal of Experimental Agriculture and Animal Husbandry.10 (43): 237.doi:10.1071/EA9700237.
^Scott KJ, Blake, JR, Stracha, G, Tugwell, et al. (1971). "Transport of Bananas at Ambient Temperatures using Polyethylene Bags".Tropical Agriculture (Trinidad).48:163–165.
^Scott KJ, Gandanegara S (1974). "Effect of Temperature on the Storage Life of bananas Held in Polyethylene Bags with an Ethylene Absorbent".Tropical Agriculture (Trinidad).51:23–26.
^Álvarez-Hernández MH, Artés-Hernández F, Ávalos-Belmontes F, Castillo- Campohermoso MA, Contreras-Esquivel JC, Ventura-Sobrevilla JM, et al. (2018). "Current scenario of adsorbent materials used in ethylene scavenging systems to extend fruit and vegetable postharvest life".Food Bioproc Technol.11 (3):511–525.doi:10.1007/s11947-018-2076-7.
^abc"Wetland Warrior".Dirty Jobs. Season 6. Episode 2.
^Brody E (February 2000)."Victor DeLor contractor profile".PaintPRO.2 (1).Archived from the original on 2008-07-23. Retrieved2009-11-12.One of the techniques DeLor is known for among designers and clients is the special effects he creates with various chemical solutions. When applied to wood surfaces, these chemicals give a weathered appearance to new wood. ... To achieve the aesthetic on interior surfaces, DeLor often uses a mixture of water and potassium permanganate, a dry powder chemical.
^Binder R, Machata G, Stead H (May 2003). "[Analysis of potassium permanganate as addictive drug "precursor"]".Archiv für Kriminologie.211 (5–6):160–165.PMID12872685.
^Glauber JR (1659).Prosperitas Germaniae [The prosperity of Germany, part 3]. Amsterdam, Netherlands: Johann Jansson. pp. 93–94.… donec tandem Magnesiam istam nitro fixo permixtam, in crucibulo forti coctione a nitro reseratam vidi, unde elegans color purpureus provenit, massam hanc effusam in pulvere redegi, aqua calida extraxi, per filtrum liquorem transmisi. Tandem vero elegantissimum purpureum, igneumque liquorem accepi, qui fere singulis horis in frigore tantummodo consistens colorem permutavit, sic ut jam viridis, jam caerulei, jam sanguinei coloris sponte sua factus sit, mox iterum alios elegantissimos colores receperit. [… until finally I saw [that] by mixing thatmagnesia [i.e.,magnesia nigra,pyrolusite, the ore containingmanganese dioxide ] with fixedniter [i.e., inert niter, potassium carbonate], by cooking [it] in a strong crucible, [the colored compound was] released by the niter, whence a fine purple color arises; this mass [was] poured out, reduced to powder, extracted with hot water, [and] the solution passed through a filter. Then I got a truly most elegant, purple, and fiery solution, which nearly every hour ([while] standing just in the cold) changed color, so that it was spontaneously made now green, now blue, now red in color; soon again it received other most elegant colors.]
^Cotton FA, Wilkinson G, Murillo CA, Bochmann M (1999).Advanced Inorganic Chemistry (6th ed.). Wiley-VCH.ISBN0-471-19957-5.
^Barthel H, Duvinage B (2000). "Clemens Winkler. His Experiments with Ozone in 1892".Praxis der Naturwissenschaften, Chemie.49: 18ff.
^Dzhabiev TS, Denisov NN, Moiseev DN, Shilov AE (2005). "Formation of Ozone During the Reduction of Potassium Permanganate in Sulfuric Acid Solutions".Russian Journal of Physical Chemistry.79:1755–1760.
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