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Description and features

Rostabil DDPP (Diisodecyl phenyl phosphite) is a clear liquid which has C26H47O3P as chemical formula. It is an alkyl-aryl phosphite which finds its application as a color and processing stabilizer in ABS, polycarbonate, polyurethane, coatings and PET fiber where regulatory approval for food contact is not required. It can be used as a secondary stabilizer to improve color and heat stability in PVC.

Diisodecyl phenyl phosphite is also known as phosphorous acid diisodecyl phenyl ester and Phenyl diisodecyl phosphite.


Europe: Provided Rostabil DDPP is on stock in our local warehouses our lead time is about one week if delivered in 200 KG drums.

United States, Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

This substance (CAS: 25550-98-5) has been registered (FULL) under REACH (EC) 1907/2006.

Product Identification

CAS number 25550-98-5
EC number 247-098-3
HS code 2920 90 85
EC nameDiisodecyl phenyl phosphite


Appearance Clear liquid @ 20 – 25 ºC
Acid Value ≤0.1 (mg KOH/g)
Free phenol≤1.0 %


Available packaging: 200 KG drums.
Special packaging is available on request.


Store Diisodecyl phenyl phosphite in a cool, dry and well-ventilated area and in line with legal requirements.
Keep DDPP away from heat sources and oxidizing agents.


A Material Safety Data Sheets (MSDS) is available for Rostabil DDPP and all other products supplied by Vesta Chemicals BV.

An MSDS describes the hazards of a product and explains how a product can be safely handled, used and stored. Besides it provides important regulatory and emergency response information for the purchased product.

Molecular and structural information

Molecular formula C26H47O3P
Molecular weight 438.64 g/mol
Smiles notation P(=O)(Oc1ccccc1)(OCCCCCCCC(C)C)OCCCCCCCC(C)C
Structural formula 25550-98-5

Physicochemical information

Boiling point 478.99 °C
Flash point 296.30 °C
Melting point 90.17 °C
Partition coefficient (log Pow) 9.32 @ 25 °C
Relative density 0.94 – 0.96 @ 20 g/ml
Refractive index 1.4800 – 1.4860 @ 20 ºC
Solubility in water 0.182 mg/l
Specific gravity 0.930 – 0.950g/m3 (25 ºC/15 ºC)
Vapour pressure 0.0076 Pa @ 25 °C
Diisodecyl phenyl phosphite | CAS: 2550-98-5 | Disclaimer. This information is supplied solely for informational purposes and Vesta Chemicals bv makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.