Agent Name

Manganese

CAS Number

7439-96-5

Formula

Mn

Major Category

Metals

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] 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.)

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

Bioaccumulates

Yes

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) [metal and fume]

IDLH (NIOSH)

500 mg/m3

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]

Reference Link

Blood manganese as an exposure biomarker: state of the evidence.

Adverse Effects
Asthma

Yes

Toxic Pneumonitis

Yes

Neurotoxin

Parkinson's Syndrome

Hepatotoxin

Hepatotoxin, Secondary

Reproductive Toxin

Yes

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Search TOXNET

Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: