Triethyl phosphite

Triethyl phosphite (CAS 122-52-1), abbreviated TEP, is a trialkyl phosphite ester used as a reactive intermediate and stabilizer in polymer, lubricant and agrochemical manufacturing. Also known as ethyl phosphite.

Where is Triethyl phosphite used?

• Polymer production: stabilizer and processing aid protecting polyolefins and engineering resins from oxidative degradation during high-temperature compounding
• Lubricant and metalworking fluids: antiwear additive precursor forming protective phosphorus-containing films on metal surfaces
• Agrochemical synthesis: building block for organophosphate active ingredients such as pesticides and herbicides via Michaelis–Arbuzov reactions
• Catalyst systems: ligand precursor in transition metal catalysts for polymerization and fine chemical processes
• Depending on the application it acts as a ligand, antioxidant precursor or catalyst component.

Good to know: High-purity grades are used where trace impurities affect reaction selectivity. Proper handling is required to maintain the integrity of the chemical during storage.

Commercial specifications

• Technical grade, purity typically 97% to 99%+
• High-purity grades for catalyst and synthesis applications
• Clear, colorless liquid in standard drums and IBCs