Methylcyclopentadienyl manganese tricarbonyl

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 #1

Biomedical References

Yes

Yes

0.2 mg/m3, as Mn

0.047 mm Hg

LC50 (rat) = 8.5 ppm/4 hr;

Explanatory Notes

VP from HSDB (at 20 deg C); VP = 7 mmHg at 212 degrees F; Flash point = 230 deg F; [CHEMINFO]

Other CNS neurotoxin

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Diseases

Occupational diseases associated with exposure to this agent:

• Encephalopathy, acute toxic
• Manganese, chronic toxic effect