Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

tert-Butyl methyl ether

tert-Butyl methyl ether is a liquid with a terpene-like odor.

CAS 1634-04-4 Danger

01 · Identification

What tert-Butyl methyl ether is

tert-Butyl methyl ether is a liquid with a terpene-like odor. It boils at 55.1 °C, melts at -109 °C.

Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).

CAS number1634-04-4
EC number216-653-1
Index number603-181-00-X
Chemical class Hazardous Air Pollutants (HAPs)

Other names for tert-Butyl methyl ether

  • MTBE
  • 2-methoxy-2-methylpropane

02 · GHS classification

Hazards and label elements

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Signal wordDanger
Hazard statements assigned to tert-Butyl methyl ether
CodeHazard statement
H225 Highly flammable liquid and vapour.
H315 Causes skin irritation.

Precautionary statements: P210, P233, P241, P242, P264, P280, P302, P313, P332, P352, P403

03 · Physical and chemical properties

tert-Butyl methyl ether properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Property Value Conditions Source
Boiling point 55.1 °C (131.2 °F) HSDB
55.22 °C (131.4 °F) at 760 mmHg CAMEO
55 °C (131 °F) ICSC
Melting point -108.6 °C (-163.5 °F) HSDB
-109 °C (-164.2 °F) CAMEO
Density 0.7405 g/cm³ HSDB
0.7405 g/cm³ at 20 °C CAMEO
0.7353 g/cm³ at 25 °C HSDB
Solubility Solubility of water in methyl t-butyl ether: 1.5 g/100 g; unstable in acid solution HSDB
4.8 g/100 g in water HSDB
In water, 51,000 mg/L at 25 °C at 25 °C HSDB
Vapor pressure 202.517 mmHg at 20 °C ICSC
245 mmHg at 25 °C HSDB
250 mmHg at 25 °C, extrapolated HSDB
Flash point -80 °C (-112 °F) HSDB
-25.56 °C (-14 °F) CAMEO
-28 °C (-18.4 °F) ICSC
Autoignition temperature 435 °C (815 °F) HSDB
375 °C (707 °F) ICSC
Lower explosive limit (LEL) 1.6 % by volume HSDB
Upper explosive limit (UEL) 8.4 % by volume HSDB
15.1 % by volume ICSC
Vapor density 3 (air = 1) ICSC
Odor threshold Odor Threshold Low: 0.05 [ppm] Haz-Map
Odor Threshold High: 0.13 [ppm] Haz-Map
Odor thresholds from CHEMINFO Haz-Map

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling tert-Butyl methyl ether

Storage conditions

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

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Incompatible materials: Oxidizing agents, Strong acids

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

Ethers, such as METHYL TERT-BUTYL ETHER, can act as bases. They form salts with strong acids and addition complexes with Lewis acids. The complex between diethyl ether and boron trifluoride is an example. Ethers may react violently with strong oxidizing agents. In other reactions, which typically involve the breaking of the carbon-oxygen bond, ethers are relatively inert.

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check tert-Butyl methyl ether in the storage compatibility matrix →

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