Agent Name

Methylcyclopentadienyl manganese tricarbonyl

Alternative Name

MMT

CAS Number

12108-13-3

Formula

C9-H7-Mn-O3

Major Category

Metals

Synonyms

CI-2; Combustion Improver-2; Manganese, tricarbonylmethylcyclopentadienyl; 2-Methylcyclopentadienyl manganese tricarbonyl; MMT; [NIOSH]

Category

Metals, Organic Compounds

Description

Yellow to dark-orange liquid with a faint, pleasant odor. [Note: A solid below 36 degrees F.] [NIOSH]

Sources/Uses

Used as a "combustion improver"; [ACGIH] Its use as a gasoline additive was banned by the EPA because it interfered with catalytic converters. [Hawley]

Comments

MMT is toxic to the central nervous system by inhalation and skin absorption. The acute adverse effects in laboratory animals are similar to those of tetraethyl lead with hyperactivity and seizures. Also seen are injuries to the liver, kidneys, and lungs. MMT has a "low order of toxicity" when used as a fuel additive. [ACGIH] When MMT is used as a fuel additive, the magnitude of the risk from chronic environmental exposure is uncertain. [AJIM 2001;39:426-33] See "Manganese" and linked occupational diseases.

Reference Link

Use of MMT in Canadian gasoline: health and environment issues

Exposure Assessment
Skin Designation (ACGIH)

Yes

Bioaccumulates

Yes

TLV (ACGIH)

0.2 mg/m3, as Mn

Vapor Pressure

0.04 mm Hg

Lethal Concentration

LC50 (rat) = 8.5 ppm/4 hr;

Explanatory Notes

VP = 7 mmHg at 212 degrees F; Flash point = 230 deg F; [CHEMINFO]

Adverse Effects
Neurotoxin

Other CNS Neurotoxin

Hepatotoxin

Hepatotoxin, Secondary

Nephrotoxin

Yes

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

Search ChemIDplus

Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent: