Phosphates automatic dishwashing detergents

About 264,000 metric tons of elemental capacity is available in North America, plus another 79,000 t (P equivalent) of purified wet phosphoric acid (14). About 85% of the elemental P is burned to P2 5 hydrated to phosphoric acid. Part of the acid (ca 21%) is used direcdy, but the biggest part is converted to phosphate compounds. Sodium phosphates account for 47% calcium, potassium, and ammonium phosphates account for 17%. Pinal apphcations include home laundry and automatic dishwasher detergents, industrial and institutional cleaners, food and beverages, metal cleaning and treatment, potable water and wastewater treatment, antifree2e, and electronics. The purified wet acid serves the same markets. 

The use of chlorinated trisodium phosphate is declining. It has been largely replaced by chlorinated isocyanurates in powdered abrasive cleansers and automatic dishwash detergents to reduce cost, improve performance, or comply with restrictions on the use of phosphates. Some chlorinated trisodium phosphate is stiU used in commercial laundries and in disinfectant cleaners. 

Phospha.tes, Pentasodium triphosphate [7758-29-4] sodium tripolyphosphate, STPP, Na P O Q, is the most widely used and most effective builder in heavy-duty fabric washing compositions (see also Phosphoric acid and phosphates). It is a strong sequestrant for calcium and magnesium, with a p c of ca 6, and provides exceUent suspending action for soils. Because of its high sequestration power, it also finds extensive appHcation in automatic-dishwashing detergents. Sodium tripolyphosphate forms stable hydrates and thus aids in the manufacture of crisp spray-dried laundry powders. 

Does the phosphate ion, a common additive to automatic dishwasher detergent, tend to behave as an acid or a base Explain ... 

Automatic Dishwash Detergent-Consumer (Phosphate. Chlorine Free. Powder)... 

Consumer product manufacturers are aware of the problems caused by phosphates and have been researching ways to minimize or even altogether eliminate phosphates from their formulations. There are now a number of automatic dishwashing detergents that are phosphate free or have low levels of phosphate. Some of these are listed in Table 3.11. ... 

List of Automatic Dishwashing Detergents with Little to No Phosphate... 

Automatic Dishwashing Detergents Type Phosphate Content (%)... 

The standard recommendation of most public agencies has been to wash hard surfaces with a solution of TSP (trisodium phosphate), sold at hardware stores, or a phosphate-containing automatic dishwashing detergent. Phosphate was believed to be effective for dissolving lead dust. 

Hard horizontal surfaces should be damp mopped or sponged with a solution of water and household detergent or a lead-specific detergent. [If TSP (trisodium phosphate) or a phosphate-containing automatic dishwashing detergent is used, precautions should be taken, as described in Chapter 3.]... 

The polycarboxylate builders inhibit the growth of inorganic crystals, which would be formed in their absence during the washing process when phosphate-free or low-phosphate detergents are used. Another function of the polycarboxylates is their ability to disperse soil as well as prevent redeposition of the soil and minimize incrustations of insoluble salts on the fabric. Polycarboxylates are also used as dispersants and to provide shine in formulations for automatic dishwashing machines. 

When the detergent formulator has to exclude the zeolite from the new zero-phosphate builder systems, the intrinsic difficulty of replacing phosphate in an automatic dishwashing product becomes evident. These objective technical difficulties have stopped the market from moving to low- and zero-phosphate detergents for at least a decade. The initial attempts were directed at zero-phosphate formulations, where some polymers, hav-... 

No one has ever before questioned the need for phosphate detergents in industrial and institutional uses such as restaurants and hospitals, and particularly in automatic dishwashing machines for home use. Hypochlorites are almost universally used to clean tables and counters in restaurants to help us from becoming infected by bacteria left in the foods spilled by other customers. This week a detergent manufacturer is test-marketing a nonphosphate nonchlorine recycled box in a western city. The printing on the box highlights what the box does not contain. 

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