TERT-BUTYL METHYL ETHER (METHYL TERT-BUTYL ETHER)

Chemical Identification
CAS #	1634-04-4
Formula	C₅H₁₂O
Synonyms	methyl-t-butyl Ether; methoxy-2-methyl propane; MTBE

Physical Properties
Physical description	A colorless liquid with a distinctive anesthetic-like odor.
Boiling point	131.4°F	Molecular weight	88.17
Freezing point/melting point	-164.2°F	Vapor pressure
Flash point	-14°F	Vapor density
Specific gravity	0.7405	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.

Bulk/Wipe Method
Wipe Sampler/Sampling media
Bulk Method

On-Site Screening Techniques
Device	CMS Chip
Model/Type	MTBE, 10-200 ppm range
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		TLV-TWA	50 ppm [1999]	PEL-TWA	40 ppm (144 mg/m³)
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	NA	Skin notation	NA	Skin notation	N	Skin notation	N
Notes: Not established		Notes: Not established		Notes:		Notes:
Health factors: See NIH-NLM PubChem.		IDLH
Carcinogenic classifications: IARC-3, TLV-A3		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3: 5 ppm/1000 ppm/5000 ppm

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Methyl tert-butyl ether

NIOSH: Pocket Guide to Chemical Hazards - Methyl tert-butyl ether

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Methyl tert-butyl ether. See annual publication for most recent information.
(absorption; metabolism) Draper, A.J., Madan, A. and Parkinson, A.: Inhibition of coumarin 7-hydroxylase activity in human liver microsomes. Arch. Biolchem. Biophys. 341(1): 47-61, 1997.
Prah, J.D., Blount, B., Cardinali, F.L., Ashley, D.L., Leavens, T. and Case, M.W.: The development and testing of a dermal exposure system for pharmacokinetic studies of administered and ambient water contaminants. J. Pharmacol. Toxicol. Methods 47(3): 189-195, 2002.
(clinical use) Hellstern, A., et al.: Dissolution of gallbladder stones with methyl tert-butyl ether and stone recurrence: a European survey. Dig. Dis. Sci. 43(5): 911-920, 1998.
(general reviews) Borak, J., Pastides, H., Van Ert, M., Russi, M. and Herzstein J.: Exposure to MTBE and acute human health effects: a critical literature review. Human and Ecological Risk Assessment 4(1): 177-200, 1998.
No Authors. Methyl tert-butyl ether . IARC Monogr. Eval. Carcinog. Risks Hum. 73: 339-383, 1999.

Last Updated Date : 01/12/2021

TERT-BUTYL METHYL ETHER (METHYL TERT-BUTYL ETHER)

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References