Ingredient Dictionary

T-BUTYL METHYL ETHER

Methyl tert-butyl ether is an ether having methyl and tert-butyl as the two alkyl components.

Definition

Methyl tert-butyl ether is an ether having methyl and tert-butyl as the two alkyl components. It has a role as a metabolite, a non-polar solvent and a fuel additive.

Source: PubChem

US FDA substance register · UNII 29I4YB3S89 · registered name tert-Butyl methyl ether · single chemical substance

Source: US FDA Unique Ingredient Identifier (UNII)

Cosmetic roles

Base that dissolves other ingredientsSOLVENT

Safety & regulatory references

Not classified under Korea’s toxic-substance GHS list · existing chemical substance

Source: Korea toxic substances GHS register (NIER)

More data — names, identifiers, properties, test records, literature

Names & identifiers

T-BUTYL METHYL ETHERINCIPropane, 2-methoxy-2-methyl-Synonym

CAS No.chemical registry number: 1634-04-4
EC No.EU chemical inventory number: 216-653-1
DTXSIDUS EPA chemical ID: DTXSID3020833
DTXCIDUS EPA compound ID: DTXCID30833

IUPAC: 2-Methoxy-2-methylpropane
Molecular formula: C5H12O
Molecular weight: 88.15 g/mol

Measured properties

Appearance: 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. · Gas Vapor, Liquid
Odour: Terpene-like odor
Boiling point: 131.4 °F at 760 mmHg (USCG, 1999) · 55.1 °C
Melting point: -164.2 °F (USCG, 1999) · -108.6 °C
Solubility: Solubility of water in methyl t-butyl ether: 1.5 g/100 g, unstable in acid solution · In water, 51,000 mg/L at 25 °C
Density: 0.7405 at 68 °F (USCG, 1999) - Less dense than water, will float · 0.7353 g/cu cm at 25 °C
Stability: Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands. · Unstable in acid solution.
Dissociation constant: pKa = -3.70
Colour: colourless
Odour threshold: 0.6 ppm
Melting/freezing point: -109 ℃
Initial boiling point and range: 55 ℃
Flash point: -28 ℃(C.C.)
Evaporation rate: &amp, lt, 1
Upper/lower flammability or explosive limits: 15.1 / 1.6 %
Vapour pressure: 27 ㎪ (20℃)
Water solubility: 4.2 g/100㎖ (20℃)
Vapour density: 3
Relative density: 0.7
n-Octanol/water partition coefficient (Kow): 0.94
Auto-ignition temperature: 375 ℃
Molecular weight: 88.2

Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.

Source: PubChem · KOSHA safety data sheets (Korea)

What products actually use it for

What the 14 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.

Solvent6
Intermediate3
Fuel agents2
Fuel2
Flavouring and nutrient1

Source: US EPA CompTox dashboard

Irritation and sensitisation studies

3 skin studies and 1 eye studies are on record.

Classed as moderate1

The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.

See all 4 studies

Category 2
Skin Irritation · Screening
Not classified
Skin Sensitization · Screening
Skin Irrit. 2
Skin Irritation · Authoritative
Category 2B
Eye Irritation · Screening