Potassium permanganate (KMnO4) is a strong oxidizing agent . As an oxidizing agent it has the ability to add oxygen, remove hydrogen or remove electrons from an element or compound. Potassium permanganate is made up of 1 manganese atom surrounded by 4 oxygen atoms. The molecular weight of permanganate is 158.04 g/mol.
Potassium permanganate has the ability to “oxidize” soluble manganese and iron in drinking water to an insoluble manganese dioxide and iron oxide that can be removed by filtration. If these compounds were left untreated, they would cause staining of plumbing fixtures such as toilets, sinks and bath tubs and impart a bad taste to the water.
Potassium permanganate is recognized by its characteristic purple to pink color when made into a solution. In high concentrations it is a dark purple color.
Potassium Permanganate has been used in many applications over the years from drinking water treatment to pharmaceutical manufacture. In drinking water treatment, Potassium Permanganate is used to oxidize iron, manganese, hydrogen sulfide, arsenic, to improve taste and odor and is used as a preoxidant for disinfection by-product control. Potassium Permanganate can help to produce high quality water and to meet strict drinking water standards. In pharmaceutical applications it has been used to oxidize functional groups, such as aromatic side chains to carboxylic acids, organic sulfides to sulfones and to produce antibiotics and tranquilizers.
Listed below are some of the many applications of potassium permanganate. Permanganate is a powerful oxidizing agent. The optimum condition under which it is to be used can be easily established through technical service evaluations or laboratory testing.
Oxidation and Synthesis - Organic chemicals and intermediates manufacture. Oxidizes impurities in organic and inorganic chemicals.
Water Treatment - Oxidizes iron, manganese, and hydrogensulfide; controls taste and odor; and is an alternate pre-oxidant for Disinfection By-Product (THMs and HAAs) control.
Municipal Wastewater Treatment - Destroys hydrogen sulfide in wastewater and sludge. Improves sludge dewatering.
Industrial Wastewater Treatment - Oxidizes hydrogen sulfide, phenols, iron, manganese, and many other organic and inorganic contaminants; resultant manganese dioxide aids in removing heavy metals.
Metal Surface Treatment - Conditions mill scale and smut to facilitate subsequent removal by acid pickling in wrought metals manufacturing and jet engine cleaning.
Equipment Cleaning - Assists in cleaning organic and inorganic residues from refining and cooling towers and other processing equipment. Decontaminates hydrogen sulfides, pyrophoric iron sulfides, phenols, and others.
Purification of Gases - Removes trace impurities of sulfur, arsine, phosphine, silane, borane, and sulfides from carbon dioxide and other industrial gases.
Mining and Metallurgical - Aids in separation of molybdenum from copper; removes impurities from zinc and cadmium; oxidizes flotation compounds. Removes iron and manganese from acid mine drainage.
Hazardous Waste Treatment or Remediation - Treats phenols, chlorinated solvents (TCE, PCE), tetraethyl lead, chelated metals, cyanides, and sulfides.
Slag Quenching - Controls hydrogen sulfide and acetylene emissions during quenching of hot slag.
Food Processing - Controls sulfides, soluble animal oil, grease, organic acids, ketones, nitrogen compounds, mercaptans, and BOD.
Formula Weight 158.0 g/mol
Form Granular Crystalline
Solid 2.703 g/cm3
3% Solution 1.020 g/mL by weight, 20°C / 4°C
Bulk Density Approximately 100 lb/ft3
Decomposition may start at 150 °C / 302 °F
Crystals or granules are dark purple with a metallic sheen, sometimes with a dark bronze-like appearance. Potassium permanganate has a sweetish, astringent taste and is odorless.
HANDLING, STORAGE, AND INCOMPATIBILITY
Protect containers against physical damage. When handling potassium permanganate, respirators should be worn to avoid irritation of or damage to mucous membranes. Eye protection should also be worn when handling potassium permanganate as a solid or in solution.
Potassium permanganate is stable and will keep indefinitely if stored in a cool, dry area in closed containers. Concrete floors are preferred to wooden decks. To clean up spills and leaks, follow the steps recommended in the MSDS. Be sure to use goggles, rubber gloves, and respirator when cleaning up a spill or leak.
Avoid contact with acids, peroxides, and all combustible organic or readily oxidizable materials including inorganic oxidizable materials and metal powders. With hydrochloric acid, chlorine gas is liberated. Potassium permanganate is not combustible, but will support combustion. It may decompose if exposed to intense heat. Fires may be controlled and extinguished by using large quantities of water. Refer to the MSDS for more information.
Potassium permanganate is compatible with many metals and synthetic materials. Natural rubbers and fibers are often incompatible. Solution pH and temperature are also important factors. The material must be compatible with either the acid or alkali also being used.
In neutral and alkaline solutions, potassium permanganate is not corrosive to iron, mild steel, or stainless steel; however, chloride corrosion of metals may be accelerated when an oxidant such as permanganate is present in solution. Plastics such as polypropylene, polyvinyl chloride Type I (PVC I), epoxy resins, fiberglass reinforced plastic (FRP), Penton, Lucite, Viton A, and Hypalon are suitable. Teflon FEP and TFE, and Tefzel ETFE are best. Refer to Material Compatibility Chart.
Aluminum, zinc, copper, lead, and alloys containing these metals may be (slightly) affected by potassium permanganate solutions. Actual studies should be made under the conditions in which permanganate will be used.
Potassium permanganate is classified by the Hazardous Materials Transportation Board (HMTB) as an oxidizer. It is shipped under Interstate Commerce Comission’s (ICC) Tariff 19.
Proper Shipping Name: Potassium Permanganate (RQ-100/45.4)
Hazard Class: Oxidizer
Identification Number: UN 1490
Label Requirements: Oxidizer
Packaging Requirements: 49 CFR Parts 100 to 199,
Sections: 173.152, 173.153, 173.194
Rail car: See Tariff for destination
Truck: No minimum
When potassium permanganate is repacked, the packing, markings, labels, and shipping conditions must meet applicable Federal regulations. See Code of Federal Regulations-49, Transportation (parts 100-199) and Federal Hazardous Materials Substances Act, 15 U.S.C. 1261.