2-METHYLCYCLOPENTADIENYL MANGANESE | Occupational Safety and Health Administration

2-METHYLCYCLOPENTADIENYL MANGANESE†

Chemical Identification
CAS #	12108-13-3
Formula	C₉H₇MnO₃
Synonyms	CI-2; Combustion Improver-2; manganese tricarbonylmethylcyclopentadienyl; 2-methylcyclopentadienyl manganese tricarbonyl; MMT; methylcyclopentadienyl manganese tricarbonyl

Physical Properties
Physical description	Yellow to dark-orange liquid with a faint, pleasant odor.
Boiling point	449°F	Molecular weight	218.1
Freezing point/melting point	34°F	Vapor pressure	7.3 mmHg at 212°F
Flash point	230°F	Vapor density	0.00064 at 70°F
Specific gravity	1.39	Ionization potential
Lower explosive limit (LEL)		Upper explosive limit (UEL)
NFPA health rating		NFPA fire rating
NFPA reactivity rating		NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)
Sampling group
Sampler/Sampling media
Sampling time^*
Sampling volume (TWA)^*
Sampling flow rate (TWA)^*
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments
Method reference
Notes
Special requirements

^* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Sampler/Sampling media

Bulk Method
Bulk Method

On-Site Screening Techniques
Device
Model/Type
Sampling information (see manufacturer instructions)

**Exposure Limits**
OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak		NIOSH REL Up to 10-hour TWA (ST) STEL (C) Ceiling		ACGIH TLV© 8-hour TWA (ST) STEL (C) Ceiling		CAL/OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak
PEL-TWA		REL-TWA	0.2 mg/m³	TLV-TWA	0.2 mg/m³ [1970]	PEL-TWA	0.2 mg/m³
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C	5 mg/m³	REL-C		TLV-C		PEL-C
Skin notation	N	Skin notation	Y	Skin notation	Y	Skin notation	Y
Notes: See Manganese compounds (as Mn), 29 CFR 1910.1000 Table Z-1		Notes:		Notes:		Notes:
Health factors: See NIH-NLM PubChem.		IDLH
Carcinogenic classifications: Not listed		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Methylcyclopentadienylmanganese tricarbonyl

NIOSH: Pocket Guide to Chemical Hazards - Methyl cyclopentadienyl manganese tricarbonyl (as Mn)

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - 2-Methylcyclopentadienyl manganese tricarbonyl. See annual publication for most recent information.
International Chemical Safety Cards (WHO/IPCS/ILO): Methylcyclopentadienyl manganese tricarbonyl.
Blanchard, K.T., Clay, R.J. and Morris, J.B.: Pulmonary activation and toxicity of cyclopentadienyl manganese tricarbonyl. Toxicol. Appl. Pharmacol. 136(2): 280-288, 1996.
Fishman, B.E., McGinley, P.A. and Gianutsos, G.: Neurotoxic effects of methylcyclopentadienyl manganese carbonyl (MMT) in the mouse: basis of MMT-induced seizure activity. Toxicology 45(2): 193-201, 1987.
Normandin, L., et al. : Manganese distribution in the brain and neurobehavioral changes following inhalation exposure of rats to three chemical forms of manganese. Neurotoxicology 25(3): 433-441, 2004.
Pohanish, R.P. (editor): Manganese, Tricarbonyl Methylcyclopentadienyl. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1450-1451.
Verschoyle, R.D., Wolf, C.R. and Dinsdale, D.: Cytochrome P450 2B isozymes are responsible for the pulmonary bioactivation and toxicity of butylated hydroxytoluene, O,O,S-trimethylphosphorothioate and methylcyclopentadienyl manganese tricarbonyl. J. Pharmacol. Exp. Ther. 266(2): 958-963, 1993.

Last Updated Date : 12/15/2020