Phosphates in detergents

Phosphates are used in modern, performance detergents for laundry washing machines, hand washing of laundry, domestic and industrial dishwashers, institutional laundry detergents, and various industrial cleaning applications.

Presentation document

The most widely used detergent phosphate is sodium tripolyphosphate (STPP à MORE [l“STPP”]), but various phosphates of sodium, potassium and other minerals are also used for specific applications. Approximately 1.0 - 1.7 million tonnes /year (as STPP) of phosphates are used  in détergents worldwide

One important function of phosphates in detergents is to enable the cleaning components of the detergent to act, by preventing interference by the “hardness” of water (mineral ions). Even in soft water, this is necessary because of calcium and magnesium ions in soils and dirt. This function is termed “builder”.

Phosphates also maintain the correct pH for cleaning components to act, in particular the high pH necessary to ensure sanitisation (killing of bacteria) in dishwashers.

However, phosphates also provide a number of other functions, directly related to cleaning: helping remove dirt from textiles, tableware or other surface, maintaining it in suspension in the wash water (anti-redeposition), preventing of scaling (on glassware) or deposits (on textiles) …

Their physical properties and excellent solubility in water, contribute to manufacture of detergents with good user characteristics: smooth powders, stable but rapidly soluble tablets …

Because of their performance and multi-functionality, P-free detergents, for any domestic applications (laundry, dishwashers …) will require the use of a number of different chemicals to achieve comparable performance, at higher cost to both the environment and to the consumer’s budget. P-free formulations will generally offer a lower performance, particularly for difficult wash loads and at lower temperatures, and risk leaving deposits or scaling on washed items. This can result in higher consumer energy (wash temperature) and water use (rinses). For many industrial cleaning applications, phosphates are considered as the only solution to ensure adequate hygiene and sanitisation.

Further information on phosphates and detergent performance à MORE [“Detergent phosphates and wash performance”]

© 2016 Global Phosphate Forum