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

Trimethyl borate

Trimethyl borate is colorless, moisture-sensitive liquid; fumes in air.

CAS 121-43-7 Danger

01 · Identification

What Trimethyl borate is

Trimethyl borate is colorless, moisture-sensitive liquid; fumes in air. It boils at 67.5 °C, melts at -29.3 °C.

Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.

CAS number121-43-7
EC number204-468-9
Index number005-005-00-1
Chemical class Flammable agents - 3rd degree

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 Trimethyl borate
CodeHazard statement
H226 Flammable liquid and vapour.
H360FD May damage fertility. May damage the unborn child.
H312 Harmful in contact with skin.

Precautionary statements: P210, P233, P241, P242, P280, P302, P312, P352, P403

03 · Physical and chemical properties

Trimethyl borate 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 67.5 °C (153.5 °F) HSDB
68 °C (154.4 °F) ICSC
68 °C (154.4 °F) at 760 mmHg DOE PAC
Melting point -29.3 °C (-20.7 °F) HSDB
-29 °C (-20.2 °F) ICSC
Density 0.915 g/cm³ HSDB
0.92 g/cm³ at 20 °C DOE PAC
Solubility Miscible with tetrahydrofuran, ether, isoporpylamine, hexane, methanol, nujol, and other organic liquids HSDB
Miscible with alcohol, ether; soluble in polar nonhydroxylic solvents HSDB
Solubility in water: reaction ICSC
Vapor pressure 137 mmHg at 25 °C HSDB
135.011 mmHg at 25 °C ICSC
Flash point 7 °C (44.6 °F) ICSC
26.67 °C (80 °F) below this value HSDB
Lower explosive limit (LEL) Reacts with oxidants causing fire and explosion hazard. table HSDB
Vapor density 3.59 (air = 1) HSDB
3.6 (air = 1) ICSC

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

04 · Handling and storage

Storing and handling Trimethyl borate

Incompatible materials

... Reacts with water and oxidizing agents.

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

Borates, such as TRIMETHYL BORATE, behave similarly to esters in that they react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters/borates with alkali metals and hydrides.

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Trimethyl borate in the storage compatibility matrix →

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