Synonyms
Manganese metal: Colloidal manganese; Manganese-55; Manganese compounds; [NIOSH]
Category
Manganese Compounds, Inorganic
Description
A lustrous, brittle, silvery solid; [NIOSH]
Sources/Uses
MINING, SMELTING, AND METALLURGY: Ore mining and crushing operations; Iron and steel production; Ferrous & nonferrous alloys (for rock crushers, railroad points and crossings, etc.); MANUFACTURING: Dry-cell batteries; Anti-knock gasoline additive; Incendiary devices; Matches; Pigments for ceramics, glass, or paints; Dyes & inks; Pesticides; USING: Grind, drill, or arc weld Mn alloy; use Mn welding rods;
Comments
Manganese is an essential nutrient in the human diet. Daily needs are in the range of 1-10 mg per day. [ATSDR ToxProfiles] Heavy exposure to fume can cause acute pneumonitis. [Harber, p. 498] Loss of libido was described in patients with chronic manganese poisoning. [Nordberg, p. 996] Sperm analysis was normal in Danish welders. [
PMID 9535501] Manganese can accumulate in the body over time to cause chronic neurological disease. [Sullivan, p. 933] Manganese is a "hepatotoxic agent." [Zimmerman, p. 4] Rodier reported manganese dust concentrations of 100-900 mg/m3 in mines in the early 1950s. [ACGIH] Air levels in past decades were in the range of 1-20 mg Mn/m3 in ferroalloy production foundries, dry battery plants, and welding operations. In recent decades, air levels decreased to <1 mg Mn/m3 in similar workplaces. [IRRST: Synthesis of scientific knowledge on the health risks following occupational exposure to manganese] ". . . we hypothesize that below the concentration of about 10 ug/m3, Mn in the body is dominated by dietary Mn, and additional inhaled Mn only causes negligible changes in Mn levels unless the inhaled amount is substantial." [Reference #2] "In total, these and other studies suggest that there are adverse neurologic health effects from Mn exposures at or below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for Mn of 0.1 mg Mn/m3." [
PMID 32472844] Occupational asthma in a welder confirmed by bronchoprovocation testing; [Malo] (Note: In Haz-Map, occupational asthma is linked to Manganese but not to manganese compounds.)
Skin Designation (ACGIH)
Insufficient data
TLV (ACGIH)
0.02 mg/m3, as Mn (respirable fraction), 0.1 mg/m3, as Mn (inhalable fraction) [metal and fume]
PEL (OSHA)
Ceiling(OSHA) = 5 mg/m3, as Mn (metal and fume)
MAK
0.2 mg/m3, as Mn (inhalable fraction), 0.02 mg/m3, as Mn (respirable fraction)
Excerpts from Documentation for IDLHs
Chronic exposures to workers averaging 47 mg/m3 caused manganese poisoning, while no cases occurred at exposures less than 30 mg/m3 [Flinn et al. 1940]. Chronic exposure to concentrations averaging 210 mg/m3 have been associated with pneumonia [Lloyd-Davies 1946]. Workers chronically exposed to concentrations of manganese dust averaging 20 mg/m3 showed signs of manganism [Smyth et al. 1973].
Explanatory Notes
Melting Point = 2271 degrees F;
Half Life
Whole body: 2-5 weeks depending on body stores; [TDR, p. 803]
Hepatotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
ACGIH Carcinogen
Not Classifiable
Diseases
Occupational diseases associated with exposure to this agent:
Processes
Industrial Processes with risk of exposure:
Activities
Activities with risk of exposure: