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Description and features

Catonium ETPB (Ethyltriphenylphosphonium Bromide / CAS: 1530-32-1) is a white to off-white crystalline powder. Its chemical formula is C20H20BrP and it is mainly used as phase transfer catalyst in the production of epoxy resins and powder coatings. It can also be used as pharmaceutical intermediate in several synthetic processes.This material is highly soluble in water and polaric solvents.

Ethyltriphenylphosphonium Bromide is also known as BETP, ETPB, ETPPB, ETPPBr, TEP and TREP.


Europe / United States: CatOnium ETPB is ➔ on stock in our local warehouses. Our lead time is about one week if delivered in 20 KG drums.

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

This substance (CAS: 1530-32-1) has been registered under REACH (EC) 1907/2006.

Product Identification

CAS number1530-32-1
EC number216-223-3
HS code2931 39 90


AppearanceWhite to off white powder
Assay≥ 98.00 %
Melting Point203 – 209 °C
Water content≤0.50 %
Loss on drying≤0.50 %


Ethyltriphenylphosphonium Bromide is a phase transfer catalyst, used to accelerate the cure of phenolic-based epoxy resins, certain fluoroelastomer resins and thermosetting powder coatings. CatOnium ETPB is also used as catalysts in the synthesis of certain organic compounds.

Compared to amines, imidazoles and quaternary ammonium salts CatOnium ETPB features considerable better latency and thermal stability. Further it offers a low odor, minimal color formation and controlled reactivity.


Available packaging: 20 KG fiber drums & 500 KG big bags.
Special packaging is available on request.


Store ethyltriphenylphosphonium bromide in a cool, dry and well-ventilated area and in line with  legal requirements.
Keep ETPB away from heat sources and oxidizing agents


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.

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

Molecular and structural information

Molecular formulaC20H20BrP
Molecular weight371.25 g/mol
Smiles notationCC[P+](C1=CC=CC=C1)(C2=CC=CC=C2)C3=CC=CC=C3.Br
Chemical formulaETPB CAS:1530-32-1

Physicochemical information

Boiling point355 ºC @ 960 hPa
Bulk density766 kg/m3
Flash point>205 ºC @ 1013 hPa
Melting point202.50 ºC at 101.3 kPa
Partition coefficient (log Pow)-0.698 @ 35 ºC (pH 4.65)
Solubility in water42.9 g/l (25 ºC)
Vapor pressure (MGM)0.000158 Pa (25 ºC)
Ethyltriphenylphosphonium bromide | CAS: 1530-32-1 | 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.