Substance fact sheet
The background information page contains information and concepts that will be useful in understanding some of the issues surrounding the NPI. It is strongly recommended that you read this before reading the information presented below.
For an explanation of some of the terms used in this page, see the Glossary
| 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). |
Physical and chemical properties Physical properties: Manganese is a very brittle, hard metal of white-grey colour. Atomic Number: 25 Atomic Mass: 54.9 Melting Point (°C): 1244 Boiling Point (°C): about 2000 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.
Chemical properties:
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Common uses 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.
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Sources of emissions Point sources Problems with air pollution can arise during the mining, crushing, and smelting of ores, during steel production, and from battery factories. Diffuse sources, and point sources included in aggregated emissions data Some agricultural and gardening applications may use products containing manganese. Some hazardous waste sites may leach manganese. Natural sources 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 Mobile sources are normally not associated with emissions of manganese. Consumer products which may contain Manganese and compounds 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. |
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Health effects How might I be exposed to Manganese and compounds? 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. By what pathways might Manganese and compounds enter my 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. Relative health hazard On a health hazard spectrum of 0 - 3 Manganese and compounds registers 1.3. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the evaluation of its tendency to cause, or not cause cancer and/or birth defects. It does not take into account exposure to the substance. Human exposure is reflected in the NPI rank given to this substance (see comparative data below). A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.  Health guidelines Australian Drinking Water Guidelines (NHMRC and ARMCANZ, 1996): Health Maximum of 0.5 mg/L (i.e. 0.0005 g/L) Aesthetic Maximum of 0.1 mg/L (i.e. 0.0001 g/L) Worksafe Australia has set the exposure standard for manganese dust, fume, and compounds (as manganese) to 1 mg/m3 (TWA). The recommended short term exposure level (STEL) for manganese fume should not exceed 3 mg/m3. See the Additional Information page for current health information. The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information. Note that the emissions data in the NPI database is not directly comparable with these guidelines. What effect might Manganese and compounds have on my health? 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. |
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Environmental effects Environmental Fate 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. Environmental Transport Manganese can be transported as particles released into the atmosphere or as dissolved compounds in natural waters. Relative hazard to the environment On an environmental spectrum of 0 - 3 Manganese and compounds registers 1.3. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8.  Environmental guidelines See the Additional Information page for current environmental guidelines. No national guidelines. What effect might Manganese and compounds have on the environment? 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. |
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Comparative data NPI Rank Approximately 400 substances were considered for inclusion on the NPI reporting list. A risk ranking was given based on health and environmental hazard identification and human and environmental exposure to the substance. Some substances were grouped together at the same rank with 208 ranks in total. Manganese and compounds was ranked as 75 out of the 208 ranks. Total hazard score (human health + environmental criteria) = 2.6.  |
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Sources of information used in preparing this article
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