Substance profile
tert-Butyl methyl ether
tert-Butyl methyl ether is a liquid with a terpene-like odor.
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).
02 · Identifiers
tert-Butyl methyl ether identifiers and molecular data
tert-Butyl methyl ether CAS number and EC number
tert-Butyl methyl ether molecular formula and molecular weight
Other names for tert-Butyl methyl ether
- MTBE
- 2-methoxy-2-methylpropane
03 · GHS classification
tert-Butyl methyl ether hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
tert-Butyl methyl ether pictograms and signal word
tert-Butyl methyl ether hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 2 | H225 | GHS02 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
tert-Butyl methyl ether hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H315 | Causes skin irritation. |
This page lists only the codes assigned to tert-Butyl methyl ether. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for tert-Butyl methyl ether
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of tert-Butyl methyl… issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
tert-Butyl methyl ether precautionary statements
CLP Annex VI assigns 11 precautionary statements to tert-Butyl methyl ether. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
tert-Butyl methyl ether name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | трет -бутилметилов етер MTBE2-метил-2-метоксипропан |
| Spanish español | Éter de terc -butilo y metilo MTBE2-metoxi-2-metilpropano |
| Czech čeština | terc -butylmethylether MTBE2-methoxy-2-methylpropan |
| Danish dansk | ( tert -butyl)methylether MTBE2-methoxy-2-methylpropan |
| German Deutsch | tert -Butylmethylether MTBE2-Methoxy-2-methylpropan |
| Estonian eesti | tert -butüülmetüüleeter MTBE2-metoksü-2-metüülpropaan |
| Greek ελληνικά | tert -βουτυλομεθυλαιθέρας MTBE2-μεθοξυ-2-μεθυλοπροπάνιο |
| English English | tert -butyl methyl ether MTBE2-methoxy-2-methylpropane |
| French français | oxyde de tert -butyle et de méthyle MTBE2-méthoxy-2-méthylpropane |
| Croatian hrvatski | tert -butil-metil-eter MTBE2-metoksi-2-metilpropan |
| Italian italiano | terz- butilmetil etere MTBE2-metossi-2-metilpropano |
| Latvian latviešu | terc -butilmetilēteris MTBE2-metoksi-2-metilpropāns |
| Lithuanian lietuvių | tret -butilmetileteris MTBE2-metoksi-2-metilpropanas |
| Hungarian magyar | terc -butil-metil-éter MTBE2-metoxi-2-metilpropán |
| Maltese Malti | eter tal-metil ta’ terz -butil MTBE2-metossi-2-metilpropan |
| Dutch Nederlands | tert -butylmethylether MTBE2-methoxy-2-methylpropaan |
| Polish polski | eter tert -butylowo-metylowy MTBE2-metoksy-2-metylopropan |
| Portuguese português | éter metílico e terc -butílico MTBE2-metoxi-2-metilpropano |
| Romanian română | terț -butil-metil-eter MTBE2metoxi-2-metilpropan |
| Slovak slovenčina | terc -butyl(metyl)éter MTBE2-metoxy-2-metylpropán |
| Slovenian slovenščina | terc -butil metil eter MTBE2-metoksi-2-metilpropan |
| Finnish suomi | Metyyli- tert -butyylieetteri MTBE2-metoksi-2-metyylipropaani |
| Swedish svenska | tert -butylmetyleter MTBE2-metoxi-2-metylpropan |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
tert-Butyl methyl ether GHS label elements
Everything CLP Annex VI fixes for tert-Butyl methyl ether, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
tert-Butyl methyl ether
- Highly flammable liquid and vapour.
- Causes skin irritation.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Use explosion-proof [electrical/ventilating/lighting/…] equipment.
- Use only non-sparking tools.
- Wash … thoroughly after handling.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF ON SKIN:
- Get medical advice/attention.
- If skin irritation occurs:
- Wash with plenty of water/…
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open tert-Butyl methyl ether in the GHS label constructor →
07 · Health hazards
tert-Butyl methyl ether health hazards and exposure limits
tert-Butyl methyl ether hazard summary
Methyl tert-butyl ether (MTBE) is a flammable liquid with a distinctive, disagreeable odor. It is made from blending chemicals such as isobutylene and methanol, and has been used since the 1980s as an additive for unleaded gasolines to achieve more efficient burning.MTBE is also used to dissolve gallstones. Patients treated in this way have MTBE delivered directly to their gall bladders through special tubes that are surgically inserted.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
tert-Butyl methyl ether carcinogenicity classification
CASRN 1634-04-4 Status: Reviewed but not listed in the Report on Carcinogens (RoC)
Source: Hazardous Substances Data Bank (HSDB)
Evaluation: There is limited evidence in humans for the carcinogenicity of methyl tert-butyl ether. There is limited evidence in experimental animals for the carcinogenicity of methyl tert-butyl ether. Overall evaluation: Methyl tert-butyl ether is not classifiable as to it carcinogenicity to humans (Group 3).
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
08 · 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.
tert-Butyl methyl ether boiling point
| 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 |
tert-Butyl methyl ether melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -108.6 °C (-163.5 °F) | HSDB | |
| -109 °C (-164.2 °F) | CAMEO |
tert-Butyl methyl ether density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.7405 g/cm³ | HSDB | |
| 0.7405 g/cm³ | at 20 °C | CAMEO | |
| 0.7353 g/cm³ | at 25 °C | HSDB |
tert-Butyl methyl ether solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| 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 |
tert-Butyl methyl ether vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 202.517 mmHg | at 20 °C | ICSC |
| 245 mmHg | at 25 °C | HSDB | |
| 250 mmHg | at 25 °C, extrapolated | HSDB |
tert-Butyl methyl ether flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | -80 °C (-112 °F) | HSDB | |
| -25.56 °C (-14 °F) | CAMEO | ||
| -28 °C (-18.4 °F) | ICSC |
tert-Butyl methyl ether autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 435 °C (815 °F) | HSDB | |
| 375 °C (707 °F) | ICSC |
tert-Butyl methyl ether lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.6 % by volume | HSDB |
tert-Butyl methyl ether upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 8.4 % by volume | HSDB | |
| 15.1 % by volume | ICSC |
tert-Butyl methyl ether vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3 (air = 1) | ICSC |
tert-Butyl methyl ether odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| 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.
09 · Fire and explosion
tert-Butyl methyl ether fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
tert-Butyl methyl ether fire potential
Flammable when exposed to heat or flame.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
tert-Butyl methyl ether storage and handling
tert-Butyl methyl ether peroxide formation
D: Other compounds that may form peroxides
Source: Lab and Research Safety, University of Minnesota
tert-Butyl methyl ether safe storage
Fireproof. Separated from strong oxidants and strong acids.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
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)
tert-Butyl methyl ether incompatible materials
Incompatible materials: Oxidizing agents, Strong acids
Source: Hazardous Substances Data Bank (HSDB)
tert-Butyl methyl ether 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 →
11 · Questions
tert-Butyl methyl ether — frequently asked questions
What is the CAS number of tert-Butyl methyl ether?
The CAS number of tert-Butyl methyl ether is 1634-04-4. Its EC number is 216-653-1.
What does a tert-Butyl methyl ether label have to show?
Under CLP Annex VI the label for tert-Butyl methyl ether carries the pictograms Flame and Exclamation mark and the signal word is Danger.
Is tert-Butyl methyl ether flammable?
Yes. CLP Annex VI assigns tert-Butyl methyl ether H225 — highly flammable liquid and vapour. The flash point reported for it is -80 °C (-112 °F) (HSDB).
Is tert-Butyl methyl ether a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for tert-Butyl methyl ether. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the boiling point of tert-Butyl methyl ether?
The boiling point reported for tert-Butyl methyl ether is 55.1 °C (131.2 °F) (HSDB).
What is the melting point of tert-Butyl methyl ether?
The melting point reported for tert-Butyl methyl ether is -108.6 °C (-163.5 °F) (HSDB).
How should tert-Butyl methyl ether be stored?
CLP Annex VI assigns tert-Butyl methyl ether the storage statement P403. 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 (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to tert-Butyl methyl ether
Keep going: substances starting with T, or search the whole database by name, CAS number, pictogram or signal word.