Email Us

Trioctyl Phosphate (TOP)

Trioctyl Phosphate (TOP) is an organophosphorus compound. It is a clear and colorless liquid that is commonly used in various industrial applications.

CAS No:78-42-2 

Molecular formula:(C8H17O)3PO 

Molecular weight: 434.63 (according to the Standard Atomic Weights 1987)

Contact Us

Trioctyl Phosphate (TOP) Cas 78-42-2 Structure Diagram



Molecular formula


Molecular weight

434.63 (according to the Standard Atomic Weights 1987)

Molecular structure diagram:

Trioctyl Phosphate (Top) of Molecular Structure Diagram

Properties: Colorless, odorless and transparent viscous liquid with boiling point of 216℃ (4 mmHg).

Trioctylphosphate (TOP) Cas 78-42-2 Introduction


Application: This product is mainly used as a working solvent in the production of hydrogen peroxide by anthraquinone method, replacing dihydroterpineol, with low volatility and high extraction partition coefficient, acting as an ideal solvent.


Packaging: 180 kg/galvanized iron drum; 1000 L/IBC ton barrel.


Storage and transportation: Stored in a dry, cool and ventilated room, avoiding violent impact and rain during transportation, with risk of combustion in case of intense heat, open flame or contact with oxidant.

Trioctyl Phosphate (TOP) Specifications


Superior Grade

Industrial Grade


Transparent oily liquid without visible impurities

Trioctyl Phosphate Content (GC)%



Dioctyl Phosphate Content (GC)%



Octanol (GC)%



Interfacial Tension mN/m(20℃ - 25℃)



Acid value mgKOH/g



Chroma (Pt-Co Color Number)



Density (20℃) g/mL



Moisture %



Viscosity (cp) 25℃ mm2/s




Plasticizer Function: In the role of a plasticizer, TOP functions by reducing the intermolecular forces between polymer chains. It effectively increases the flexibility, softness, and workability of plastics, resins, and polymers. By reducing the polymer's rigidity, TOP enhances the material's ability to be molded or shaped into desired forms


Solvent Function: TOP acts as a solvent by dissolving or dispersing substances with different polarities. It can solubilize both polar and non-polar compounds due to its own intermediate polarity. This property makes TOP useful for dissolving dyes, oils, waxes, and other materials that may be challenging to dissolve in other solvents.


Extraction Function: As an extraction agent, TOP functions by selectively binding and extracting specific metal ions from aqueous or organic solutions. It forms complexes with metal ions, allowing for their separation and purification from other substances. This function is commonly utilized in metal recovery processes and hydrometallurgical operations.


Lubrication Function: TOP functions as a lubricant additive by forming a protective film on surfaces that reduces friction and wear between moving parts. It helps to minimize heat generation and damage caused by metal-to-metal contact. TOP's lubrication function is especially valuable in high-temperature environments where conventional lubricants may fail.


Flame Retardant Function: When used as a flame retardant additive, TOP functions by forming a barrier that inhibits the spread of flames. It can act as a physical barrier or a chemical coolant, reducing the heat release rate and delaying the ignition or combustion of materials. This function enhances the fire resistance of the treated materials.


Intermediate Function: TOP serves as a chemical intermediate in the synthesis of various compounds. It participates in reactions to produce derivatives used in the manufacturing of pharmaceuticals, surfactants, and specialty chemicals. By undergoing chemical transformations, TOP contributes to the formation of desired products.

Trioctylphosphate (TOP) Precautions

Is Trioctyl Phosphate (TOP) Toxic?

TOP is generally considered to have low acute toxicity. However, like any chemical, it should be handled with care. It is important to follow appropriate safety measures, such as using protective equipment and ensuring proper ventilation, when working with or handling TOP.

Is Trioctyl Phosphate (TOP) Environmentally Friendly?

Trioctyl Phosphate is not considered environmentally friendly due to its low biodegradability. It is important to properly dispose of or recycle TOP and avoid its release into the environment to minimize potential ecological impacts.