Manganese is predominantly used to produce ferromanganese, or metallic manganese, which is used in the production of steel to improve hardness, stiffness, and strength. It is used in carbon steel, stainless steel, high-temperature steel, and tool steel, along with cast iron and superalloys. Manganese finds further applications in a number of non-ferrous alloys, especially with aluminium, magnesium, copper and zinc.
Applications for various manganese compounds follow.
- Manganese dioxide is commonly used in the production of batteries, matches, fireworks, porcelain, glass-bonding materials and amethyst glass, as the starting material for production of other manganese compounds, and as an oxidising agent.
- Manganese chloride is used as a precursor for other manganese compounds, as a catalyst in the chlorination of organic compounds, as dietary supplement/food additive, in animal feed to supply essential trace minerals, in paint driers, fertilisers, in dyeing, disinfecting, purifying natural gas, and in dry-cell batteries.
- Manganese sulfate is used in glazes, varnishes, ceramics, dyeing, fertilisers, fungicides, and ore flotation. It is also used in medicines and as a nutritional supplement.
- Potassium permanganate is used as an oxidising agent, a disinfectant, as an anti-algal agent, in metal cleaning, in tanning, bleaching, and as a preservative for fresh flowers and fruits.
- Manganese gluconate is used as a feed additive, food additive, and dietary supplement.
- Manganese oxide is used in textile printing, ceramics, paints, coloured glass, animal feeds, fertilisers, and in welding. It is used as a catalyst in the manufacture of allyl alcohol, as food additive and a dietary supplement.
- Manganese nitrate is used as a colour agent in porcelain and ceramic manufacture, as a catalyst, and in the production of manganese dioxide.
- Manganese acetate is used in textile dyeing, fertilisers, food packaging, feed additives, and in manufacturing paints and varnishes.
- Manganese carbonate is used as a pigment, drier for varnishes, in medications, and as a plant nutrient. It is used in the manufacturing of manganese salts, pharmaceuticals, animal feeds, and ceramics.
Substance name: Manganese & compounds
CASR number: 7439-96-5
Molecular formula: Mn
Synonyms: Colloidal manganese, elemental manganese, cutaval. Manganese compounds include manganese acetate (CASR# 638-38-0), manganese carbonate (CASR# 598-62-9), manganese chloride (CASR# 7773-01-5), manganese tetroxide (CASR# 1317-35-7), manganese dioxide (CASR# 1313-13-9), potassium permanganate (CASR# 7722-64-7), manganese gluconate (CASR# 6485-39-8), manganese oxide (CASR# 1344-43-0), and manganese sulfate (CASR# 7785-87-7).
Manganese is a very brittle, hard metal of white-grey colour.
Atomic Number: 25
Atomic Mass: 54.9
Melting Point: 1244°C
Boiling Point: about 2000°C
Specific Gravity: 7.2 to 7.4
Manganese is very similar to iron in its physical and chemical properties, the chief difference being that manganese is harder and more brittle but less refractory. Properties vary widely depending on the particular compound.
- Manganese acetate comes in the form of brown crystals.
- Manganese carbonate is a pink-to-white hygroscopic powder with specific gravity 3.1.
- Manganese chloride comes in the form of pink cubic hygroscopic crystals with melting point 650°C and boiling point 1190°C.
- Manganese nitrate is a colourless or pink solid in crystal form.
- Manganese dioxide is a black crystalline solid or powder with melting point 535°C and specific gravity 5.0.
- Manganese gluconate comes in the form of a light pink powder or coarse pink granules.
- Manganese oxide comes in the form of green cubic crystals or green powder.
- Manganese sulfate comes in the form of reddish crystals or pale red, slightly efflorescent crystals.
- Potassium permanganate comes as dark purple crystals with blue metallic sheen. The crystals have a specific gravity of 2.7, a vapour density of 5.4 and melt at 240°C.
Manganese exists mostly in the (II) oxidation state in natural compounds. It can also appear as manganese (IV) in manganese dioxide. Synthetic compounds are known in nearly all oxidation states between (III-) and (VII+). The metal decomposes in water and readily dissolves in dilute, non-oxidising acids and reacts vigorously with many non-metals at elevated temperatures. Finely divided manganese can combine explosively with a number of materials. Solubility of manganese compounds in water ranges from poorly soluble (manganese dioxide, manganese tetroxide, manganese carbonate, and manganese sulfide) to soluble (manganese sulfate, manganese chloride, manganese nitrate, permanganate ion).
- Manganese acetate is soluble in alcohol and water, and decomposes in cold water.
- Manganese carbonate decomposes before reaching its melting point. It is soluble in dilute acid, and insoluble in water, alcohol, and ammonia.
- Manganese chloride is soluble in water and alcohol, and insoluble in ether. It is deliquescent (i.e. if exposed to air, it absorbs moisture from the atmosphere to such an extent that it will dissolve).
- Manganese gluconate is soluble in water, and insoluble in alcohol and benzene.
- Manganese oxide is soluble in acids and ammonium chloride, and insoluble in water.
- Manganese sulfate is soluble in alcohol, and insoluble in ether.
- Manganese tetroxide is insoluble in water, and soluble in hydrochloric acid.
- Manganese dioxide is insoluble in water, and inert to most acids except when heated. With hot hydrochloric acid chlorine is evolved.
- Potassium permanganate is soluble in water, sulfuric acid and acetone.
The National Pollutant Inventory (NPI) holds data for all sources of manganese and compounds emissions in Australia.
Manganese is an essential element for humans, in fact for all living organisms including animals, plants and bacteria. Its naturally occurring concentrations are hardly toxic and relatively large doses can be tolerated without adverse effects. It is found in all human tissues, with the highest manganese concentrations in the liver, pancreas, intestinal tract and kidneys. Food is the major natural source of manganese intake and the amount of manganese in a normal diet is enough to meet daily needs with no ill health effects. Its absorption can be influenced by dietary level of manganese and iron, the type of manganese compound, iron deficiency and age. Occupational exposure to manganese can be substantial. In its acute form, manganese poisoning has an effect characteristic of other heavy metals, leading to 'metal fume fever' if dust or fume is inhaled in sufficient quantity. An airborne concentration thought to be immediately dangerous to life or health is in the order of 10,000 milligram/m3. Chronic exposure to manganese can express itself in two major ways, namely bronchitis/pneumonitis after inhalation of manganese dust, and 'manganism'. Manganism may also result from inhalation. However, the airborne manganese concentration which gives rise to these effects is different. Manganism is the effect of chronic manganese poisoning. This disease, which arises from damage to the central nervous system (CNS), usually begins with psychological symptoms such as hallucinations, emotional instability and disturbances in behaviour. These may be followed by neurological symptoms such as muscular weakness, speech disturbances and headaches, as well as symptoms resembling those of Parkinson's disease (tremors, stiffness, motor dysfunction). If exposure is terminated soon after the neurological symptoms appear, the individual generally recovers, but some speech and balance problems may remain. Individual susceptibility to the adverse effects of manganese varies considerably. The minimum dose that produces effects on the CNS is not known, but signs of adverse effects may occur at manganese concentrations ranging from 2 to 5 milligram/m3 in air. Deficiencies in the diet may predispose workers to anaemia, thus increasing susceptibility to manganese. An increased incidence of pneumonia has been reported among individuals exposed to manganese. A common effect in men who are exposed to high levels of manganese dust in air is impotence.
Entering the body
Manganese can be inhaled or ingested. Absorption of inorganic manganese through the skin appears to be negligible. However, with organo-manganese compounds there can be significant absorption through the skin.
Most exposure will be associated with drinking water and consuming foods containing manganese. Exposure to manganese and its compounds may also occur during mining and processing of the ore, manganese smelting, ferrous and non-ferrous alloying, welding/brazing processes (either from electrodes/rods or parent material), battery (dry cell and alkaline) manufacture, and production and use of manganese chemicals and fertilisers, for those involved in these industries.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for manganese fume through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 1 mg/m3
- Maximum short term exposure limit (STEL): 3 mg/m3
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
The Australian Drinking Water Guidelines include the following guidelines for acceptable water quality:
- Maximum of 0.5 milligrams per litre of water for health purposes
- Maximum of 0.1 milligrams per litre of water for aesthetic considerations
Manganese is an essential element for all living organisms including animals, plants and bacteria. Manganese and its compounds have moderate acute and chronic toxicity to aquatic life. Insufficient data are available to evaluate or predict the short-term and long-term effects of manganese and its compounds on plants, birds, or land animals. Most plants have a very high tolerance for manganese.
Entering the environment
Manganese can be transported as particles released into the atmosphere or as dissolved compounds in natural waters.
Where it ends up
Manganese occurs everywhere and can be found in nature at background levels in air, soil, water and food. Iron-manganese oxides in waters are carriers for many other inorganic and organic pollutants and are thus sources and sinks of them in aquatic environments including sediments. Airborne manganese particles settle and accumulate in the upper part of the soil and its availability for plants depends on the form of the manganese compounds and pH value of the soil.
No national guidelines.
Problems with air pollution can arise during the mining, crushing, and smelting of ores, during steel production, and from battery factories.
Diffuse sources, and industry sources included in diffuse emissions data
Some agricultural and gardening applications may use products containing manganese. Some hazardous waste sites may leach manganese.
Manganese is a naturally occurring element, although it is not naturally found in the metallic form. The earth's crust contains approximately 0.1 % manganese on average, with low levels present in lakes, streams, and the ocean. Nodules containing manganese oxides have been found on the seabed of the Pacific. More than 100 manganese minerals are known, including sulfides, oxides, carbonates, silicates, phosphates, and borates. The most important manganese mineral is native manganese dioxide (pyrolusite). Manganese ores very often occur together with iron ores.
Mobile sources are normally not associated with emissions of manganese.
Alkaline and dry cell batteries, some vitamin/mineral dietary supplements, some fertilisers, some disinfectants, some porcelain and ceramic goods. Some drinking water supplies may contain small amounts of manganese.
Sources used in preparing this information
- ChemFinder WebServer Project (1995), Manganese (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (II) acetate (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (II) chloride (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (II) gluconate (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (II) oxide (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (II) sulfate (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese (IV) dioxide (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese tetroxide or Manganese (II, III) oxide (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Manganese(II) carbonate (accessed, May, 1999)
- ChemFinder WebServer Project (1995), Potassium permanganate (accessed, May, 1999)
- Environmental Health Center (a division of the National Safety Council) Environment Writer - Chemical Backgrounders (July 1, 1997), Manganese (accessed, May, 1999)
- Environmental Health Center (a division of the National Safety Council) Environment Writer - Chemical Backgrounders (November 17, 1998), Manganese compounds 2 - Manganese gluconate, Manganous oxide, Manganese sulfate (accessed, May, 1999)
- Environmental Health Center (a division of the National Safety Council) Environment Writer - Chemical Backgrounders (October 16, 1998), Manganese compounds 1 - Manganese acetate, Manganese carbonate, Manganese chloride (accessed, May, 1999)
- Integrated Risk Information System (IRIS, September 26, 1988), Manganese (accessed, May, 1999)
- Merian, E. (editor, 1991), Metals and Their Compounds in the Environment – Occurrence, Analysis, and Biological Relevance, VCH.
- National Environment Protection Council (1998), National Environment Protection Measure for the National Pollutant Inventory. (accessed, May 1999)
- Open Data Solutions, EPA factsheets for regulated toxic chemicals (January, 1987), Manganese Nitrate (accessed, May, 1999)
- Open Data Solutions, EPA factsheets for regulated toxic chemicals (January, 1989), Manganese (accessed, May, 1999)
- Open Data Solutions, EPA factsheets for regulated toxic chemicals (July, 1986), Manganese Dioxide (accessed, May, 1999)
- Technical Advisory Panel (1999), Final Report to the National Environment Protection Council.
- US EPA TTNWeb and US OAQPS UATW, Health Effects Notebook for Hazardous Air Pollutants (December 1994), Manganese and Compounds (accessed, May, 1999)
- WebElements – The periodic table on the WWW (May 1999), Manganese (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substances Database, Manganese (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substances Database, Manganese dioxide (accessed, May, 1999)
- Worksafe Australia (1996), Hazardous Substances Database, Potassium permanganate (accessed, May, 1999)
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed December 2018.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018