Phosphino Carboxylic Acid


Phosphino carboxylic acid (PCA) associates characteristics of phosphonates and polyacrylates. The function is to provide a special equilibrium of limit inhibition and dispersancy. The Phosphino carboxylic acid (POCA) has good tolerance to chlorine. And it is also compatible with a lot of microbiological control agents.

The Phosphino carboxylic acid has excellent dispersion performance for calcium carbonate and calcium phosphate scale in a cool water system. The reason is that introducing a phosphonic group right into a carboxylic group. In addition, Phosphino carboxylic acid also has good scale inhibition for barium sulfate, strontium sulfate, and silica scale.

One more thing to note is that chlorine or other oxidizing biocides in the standard cannot affect phosphino carboxylic acid (PCA, POCA).

Phosphino Carboxylic Acid


Mechanism of Action:

Phosphino carboxylic acid inhibits scale buildup on surfaces through at least three mechanisms. (For more details, click here.)

  1. Solubility enhancement or threshold effect reduces precipitation of low solubility inorganic salts.
  2. Crystal modification, which deforms the growing organic salt crystals to give small, irregular, readily fractured crystals that do not adhere well to surfaces.
  3. Dispersing activity prevents precipitated crystals or other inorganic particles from agglomerating and depositing on surfaces. Low molecular weight polymers are widely used to inhibit scaling in industrial water treatment.


AppearanceColorless or light yellow liquid
Solid content, %50 Min.
Total phosphor (as PO43-), %0.5 Min.
Density (20℃), g/cm31.20~1.30
pH (1% water solution)3.0~5.0


Phosphino carboxylic acid has advantages in a wide range of water quality, chemical stability, strong chlorine tolerance, etc. Engineers use it as a scale and corrosion inhibitor in circulating cool water systems. And also found in the oilfield refill water system.

ChemicalsApplication AreaApplication UseFeatures and Benefits
Phosphonocarboxylic Acid (POCA)Cooling WaterCalcium carbonate and calcium phosphate scale control.Multifunctional, phosphonate, and polymer performance on the same molecule.
Sulphonated Phosphino Polycarboxylic Acid Polymer (PCA-S)Cooling WaterStabilized phosphate and zinc-based cooling water programs.Control calcium phosphate and zinc deposits.
Phosphinocarboxylic Acid Polymer (PCA)BoilersSludge dispersant.FDA-approved, it can be used in applications where steam may contact food.
Pulp & PaperDe-inking dispersant.Outperforms polyacrylates. Excellent performance under pulp and paper conditions.
Paper machine deposit.Effective against barium sulfate and calcium oxalate.


When used alone, the dosage of 5~20 mg/L is preferred. It can also be used with organophosphines, copolymers, a zinc salt, or BTA.

Packing and storage:

200L plastic drum, IBC (1000L), customers’ requirements.

200L plastic drum 1000L IBC

Storage for ten months in a shady room and dry place.


71050-62-9, 23636-66-0, CTK1A2745, DTXSID00559205, Phosphoranecarboxylicacid (8CI,9CI), ZINC113998343.