Methyl tert-butyl ether

Athanor · official

C₅H₁₂O · 88.15 g/mol

IUPAC name: 2-methoxy-2-methylpropane

Also called MTBE, tert-butyl methyl ether, TBME

Solvents

Open in Athanor

Drawn from its SMILES with RDKit

DangerHighly Flammable liquid and vapor · Causes skin irritation

Names and identifiers

IUPAC name: 2-methoxy-2-methylpropane
Synonyms: MTBE, tert-butyl methyl ether, TBME
+ 37 more
tert-Butyl methyl ether, 2-Methoxy-2-methylpropane, Methyl t-butyl ether, Propane, 2-methoxy-2-methyl-, T-BUTYL METHYL ETHER, 2-Methyl-2-methoxypropane, Methyl tertiary-butyl ether, Ether, tert-butyl methyl, Methyl 1,1-dimethylethyl ether, 1,1-dimethylethyl methyl ether, DTXSID3020833, CHEBI:27642, 29I4YB3S89, TERT-BUTOXYMETHANE, DTXCID30833, methyl tert-butyl ether (mtbe), RefChem:818082, 2-methoxy-2-methyl propane, 216-653-1, Methyl-tert-butyl ether, Methyl-t-butyl ether, tert-Butylmethyl ether, tert-butylmethylether, 2-methoxy-2-methyl-propane, tert-C4H9OCH3, methyltert-butyl ether, methyl-tert-butyl-ether, MFCD00008812, Methyl Tertiary Butyl Ether, tBME, Methyl tert butyl ether, tert-BuOMe, methyl-t-butylether, t-butylmethyl ether, methyltertbutyl ether, tertbutylmethyl ether, CCRIS 7596
Molecular formula: C₅H₁₂O
Empirical formula: C₅H₁₂O
Molecular weight: 88.15 g/mol
Exact mass: 88.08882
CAS number: 1634-04-4
PubChem CID: 15413
Canonical SMILES: CC(C)(C)OC
Isomeric SMILES: CC(C)(C)OC
InChI: InChI=1S/C5H12O/c1-5(2,3)6-4/h1-4H3
InChIKey: BZLVMXJERCGZMT-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Colorless liquid[5]
5 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Methyl tert-butyl ether appears as a colorless liquid with a distinctive anesthetic-like odor. Vapors are heavier than air and narcotic (cause drowsiness when inhaled). This liquid has a flash point lower than most ambient temperatures, so it will readily ignite under most conditions. It is less dense than water and moderately soluble in water. Used as a octane booster in gasoline. [1] CAMEO Chemicals
– Gas Vapor; Liquid [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– A colorless liquid with a distinctive anesthetic-like odor. [4] Occupational Safety and Health Administration (OSHA)
–shown Colorless liquid [5] Hazardous Substances Data Bank (HSDB)cites Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016., p. 897
Odor: Terpene-like odor[5]
Melting point: -108.6 °C[6]
4 values
4 of 4 sources agree on it (most common value).
Value As written Source
−109.0 °C -164.2 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
−109 °C -109 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
−109.0 °C -164.2 °F [4] Occupational Safety and Health Administration (OSHA)
−108.6 °Cshown -108.6 °C [6] PAC Chemical Database, U.S. Department of Energy
Boiling point: 55.2 °C (131.4 °F) at 760 mmHg (USCG, 1999)[1]
4 values
4 of 4 sources agree on it (most common value).
Value As written Source
55.2 °Cshown 131.4 °F at 760 mmHg (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
55 °C 55 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
55.2 °C 131.4 °F [4] Occupational Safety and Health Administration (OSHA)
55 °C 55 °C @760 [mm Hg] [6] PAC Chemical Database, U.S. Department of Energy
Density: 0.7353 @25 °C[6]
4 values
3 of 4 sources agree on it (most common value).
Value As written Source
– 0.7405 at 68 °F (USCG, 1999) - Less dense than water [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
– Relative density (water = 1): 0.7 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– 0.7405 [4] Occupational Safety and Health Administration (OSHA)
–shown 0.7353 @25 °C [6] PAC Chemical Database, U.S. Department of Energy
1 more value was reported but failed the checks (unreadable or out of range), so it is not shown.
Solubility in water: Solubility in water, g/100ml at 20 °C: 4.2[3]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– In water, 51,000 mg/L at 25 °C [5] Hazardous Substances Data Bank (HSDB)cites Bennett GM, Philip WG; J Chem Soc pp. 1930-7 (1928)
– Solubility in water 4wt%; solution of water in 1.3 wt% [5] Hazardous Substances Data Bank (HSDB)cites Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016., p. 897
–shown Solubility in water, g/100ml at 20 °C: 4.2 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: 1.06[3]
2 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source
– log Kow = 0.94 [5] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 15
–shown 1.06 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
pKa: pKa = -3.70[5]
Vapor pressure: 250 mmHg at 25 °C (extrapolated)[5]
3 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source
250 mmHgshown 250 mm Hg at 25 °C /extrapolated/ [5] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
200 mmHg Vapor pressure, kPa at 20 °C: 27 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
75 mmHg 75 [mm Hg] @-2 °C [6] PAC Chemical Database, U.S. Department of Energy
Flash point: -26 °C (-14 °F, USCG 1999)[1]
4 values
2 of 4 sources agree on it (most common value).
Value As written Source
−26 °Cshown -14 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
−80 °C -80 °C [5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 497-13
−28 °C -28 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
−26 °C -14 °F [4] Occupational Safety and Health Administration (OSHA)
Autoignition temperature: 375 °C[3]
2 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source
435 °C 435 °C [5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 497-13
375 °Cshown 375 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	Methyl tert-butyl ether appears as a colorless liquid with a distinctive anesthetic-like odor. Vapors are heavier than air and narcotic (cause drowsiness when inhaled). This liquid has a flash point lower than most ambient temperatures, so it will readily ignite under most conditions. It is less dense than water and moderately soluble in water. Used as a octane booster in gasoline.	[1] CAMEO Chemicals
–	Gas Vapor; Liquid	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	A colorless liquid with a distinctive anesthetic-like odor.	[4] Occupational Safety and Health Administration (OSHA)
–shown	Colorless liquid	[5] Hazardous Substances Data Bank (HSDB)cites Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016., p. 897

Value	As written	Source
−109.0 °C	-164.2 °F (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
−109 °C	-109 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−109.0 °C	-164.2 °F	[4] Occupational Safety and Health Administration (OSHA)
−108.6 °Cshown	-108.6 °C	[6] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
55.2 °Cshown	131.4 °F at 760 mmHg (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
55 °C	55 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
55.2 °C	131.4 °F	[4] Occupational Safety and Health Administration (OSHA)
55 °C	55 °C @760 [mm Hg]	[6] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	0.7405 at 68 °F (USCG, 1999) - Less dense than water	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–	Relative density (water = 1): 0.7	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	0.7405	[4] Occupational Safety and Health Administration (OSHA)
–shown	0.7353 @25 °C	[6] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	In water, 51,000 mg/L at 25 °C	[5] Hazardous Substances Data Bank (HSDB)cites Bennett GM, Philip WG; J Chem Soc pp. 1930-7 (1928)
–	Solubility in water 4wt%; solution of water in 1.3 wt%	[5] Hazardous Substances Data Bank (HSDB)cites Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016., p. 897
–shown	Solubility in water, g/100ml at 20 °C: 4.2	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow = 0.94	[5] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 15
–shown	1.06	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
250 mmHgshown	250 mm Hg at 25 °C /extrapolated/	[5] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
200 mmHg	Vapor pressure, kPa at 20 °C: 27	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
75 mmHg	75 [mm Hg] @-2 °C	[6] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
−26 °Cshown	-14 °F (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
−80 °C	-80 °C	[5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 497-13
−28 °C	-28 °C c.c.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−26 °C	-14 °F	[4] Occupational Safety and Health Administration (OSHA)

Value	As written	Source
435 °C	435 °C	[5] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 497-13
375 °Cshown	375 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 6
Rings: 0
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 1
H-bond donors: 0
H-bond acceptors: 1
Rotatable bonds: 0 computed here · PubChem 1
TPSA (Å²): 9.2
Formal charge: 0
XLogP3: 0.9 PubChem
Complexity: 33 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C68.13%
H13.72%
O18.15%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: 1.43 Crippen (Wildman and Crippen 1999)
log S (water solubility): -1.29 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 2.06 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 88.15
log P ≤ 5 (Crippen): 1.43
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 1

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Harmonized EU classification (CLP Annex VI). Source [7].

Flammable
Harmful or irritant

H225Highly Flammable liquid and vapor
H315Causes skin irritation

Precautionary statements: P210, P233, P240, P241, P242, P243, P264, P280, P302+P352, P303+P361+P353, P321, P332+P317, P362+P364, P370+P378, P403+P235, P501

View all classifications (3)

[7] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH225, H315
[8] European Chemicals Agency (ECHA) · 2,105 reports · DangerH225, H315
[5] Hazardous Substances Data Bank (HSDB) · DangerH225, H315

Exposure limits

TLV: 50 ppm as TWA; A3 (confirmed animal carcinogen with unknown relevance to humans).[3]
TLV-TWA (Time Weighted Average): 50 ppm [1999][4]
EU-OEL: 183.5 mg/m[3]
MAK (Maximale Arbeitsplatz Konzentration): 180 mg/m[3]

First aid

Inhalation: Move victim to fresh air; call emergency medical care. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. EYES OR skin: Flush with running water for at least 15 minutes; hold eyelids open if necessary. Remove and isolate contaminated clothing and shoes at the site. Keep victim quiet and maintain normal body temperature. Ingestion: If victim is unconscious or having convulsions, do nothing except keep victim warm. (USCG, 1999)[1]
General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[9]
Fresh air, rest. Artificial respiration may be needed. Refer for medical attention.[3]
Remove contaminated clothes. Rinse and then wash skin with water and soap.[3]

Storage

Fireproof. Separated from strong oxidants and strong acids.[3]
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): Flammable liquids[5]
(methyl tert-butyl ether) can be stored in nonpressurized containers. Carbon steel can be used as container material, as well as aluminum, brass, copper, polyethylene, or polypropylene. Teflon, Buna-N, and other fuel-resistant plastics and rubbers can be used for seals; the use of vinylidene fluoride-hexafluoropropene copolymer (Viton) is not recommended.[5]

Incompatibilities

Incompatible materials: Oxidizing agents, Strong acids[5]

Safety data sheets on the supplier’s page: MP Biomedicals, Thermo Fisher Scientific, Sigma-Aldrich.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[4]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
[5]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[6]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[7]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
[8]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[9]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
[10]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[11]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[12]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[13]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[14]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[15]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.