Trade Name:TEO / TEOF
Chemical Name:Triethyl Orthaformate (TEOF / TEO); ethyl orthoformate; Triethoxymethane
Molecular Formula:HC(OC2H5)3
Molecular Weight:148.20
UN Number: 2524
CAS Number:122-51-0

Harttive TEO, known as Triethyl orthoformate (TEO/TEOF), is an orthoester compound, classified as ester, its molecular formula is HC(OC2H5)3. Triethyl orthoformate is clear, colorless liquid with pungent odor. Slightly soluble in water and decomposable in water; miscible with ethanol and ether. Low toxicity. Generally, Triethyl orthoformate (TEOF) used as pharmaceutical intermediate (API) in medical areas, such as the preparation of antimalarial drugs chloroquine and quinpir. It is also used as a raw material for photographic agents and as a reagent in the synthesis of Bodroux-Chichibabin aldehyde.

Harttive TEO is used as a stabilizer for polyurethane coatings. It is compatible with isocyanate and polyester. Being a moisture scavenger in isocyanate and polyester coating systems. Trials should always be carried out to determine the suitability of the product for the intended application. Generally, Harttive TEO is widely applied on silicon, paints, sealants, sprays and etc. Besides, Harttive TEO can also be used to make the intermediates and API (Active Pharmaceutical Ingredients) in medical fields.


180 KG/Iron Drum.

It can be packaged on demand. Please inquire.      

Harttive TEO, Triethyl orthoformate (TEO) can be active with water and form HCOOCH2CH3 and CH3CH2OH.

Below is the chart to compare the usage of MSI and TEO.





Monofunctional isocyanate



MSI is acted with water to produce carbon dioxide. It’s used to dehydrate for solvent/pigment/filler. Generally, MSI is applied as an pre-dehydrating agent on Dual-component PU coating or applied as a stabilizer agent on Single-component PU coating to improve storage qualitative.

Triethyl orthoformate (TEO) can be acted with water and form HCOOCH2CH3 and CH3CH2OH.

Molecular weight



Addition (1g water)

10.9g*1.1= 12g



Applied for One-component PU pre-handling hardener.  Do NOT  add in the mixture of main agent & hardener, otherwise, MSI will be reacted with the NCO of main agent.

None limitation.

Reaction speed


The reaction is faster after heating.

*There are two significant advantages of TEO in comparison of MSI. First, you can save 25% cost due to the dosage is only 9 grams (75%). Furthermore, there is no limitation on handling. It’s simple, easy and poka-yoke (mistake-proofing).

Scientific nameTriethyl Orthaformate (TEOF / TEO); ethyl orthoformate; Triethoxymethane
Form suppliedColorless transparent liquid
UsesStabilizer for polyurethane coatings
Effective contentActive substance(Gas-chromatographic method): min. 98%
Other dataFlash point: (DIN51755) 37℃
 Density: 20℃ (DIN51757) around 0.9 g/cm3
 Boiling point: around 140℃
 *These values provide general information and are not parts of the product specification
 Generally speaking, Harttive TEO is compatible with Isocyanate and polyester.
CompatibilityHowever, the storage stability of all combinations cannot be guaranteed.
ApplicationHarttive TEO is used in Isocyanate and polyester coating systems as a moisture scavenger. Trials should always be carried out to determine the suitability of the product for the intended application.
StorageHarttive TEO is sensitive to moisture and should therefore be stored in its original sealed containers. Please store in a dry, ventilation place and keep away from tinder heat source.
SafetyAny existing national regulations on the dangerous and corrode matter should be observed. The product is flammable and the container should therefore be kept away from ignitable sources. Precautions against electrostatic pick-up should be taken. The product must only be handled in explosion-proof rooms.
 Skin and eyes contacting with the product as well as inhalation of the vapors should be avoided. We recommend the wearing of safety goggles and protective gloves.
Package180 KG/Iron Drum

Triethyl orthoformate (TEO/TEOF) is a key organic synthesis intermediate. It is mainly used to synthesize pharmaceutical and pesticide products, such as quinolones antibiotics and Amitraz. It is also widely used in coating, dye and perfume industries. In addition, Harttive TEO is used as a moisture scavenger in isocyanate and polyester coating systems.

  • Dyes
  • Intermediate for Pharmaceuticals
  • Pesticides
  • Fragrance (Citric acid)
  • Isocyanate and polyester coating
  • Sealants and sprays