hexametaphosphate

Hexametaphosphate is a polyphosphate used commercially in a variety of applications. It refers to a cyclic metaphosphate consisting of six linked phosphate units, typically forming salts such as sodium hexametaphosphate and potassium hexametaphosphate. In these salts the hexametaphosphate anion acts as a robust chelating and sequestering agent. Calcium hexametaphosphate is an insoluble salt variant used mainly for scale inhibition.

In water treatment and detergents, hexametaphosphate functions as a sequestrant that binds calcium, magnesium, and other metal ions. This helps prevent mineral deposition, clarifies solutions, and improves the effectiveness of detergents and cleaning products. The compound is also used as a deflocculant and stabilizer in various industrial processes.

In the food and beverage industry, hexametaphosphate serves as an additive and texture modifier. It acts as a sequestrant to control metal-catalyzed oxidation, as a stabilizer for emulsions, and as a thickener or gelling agent in some products. In the United States and Europe, certain hexametaphosphate salts are approved as food additives under regulatory codes for specific uses and limits.

Chemical behavior and safety: hexametaphosphate is relatively stable under neutral to basic conditions but hydrolyzes to orthophosphate under acidic conditions. It is generally recognized as safe for specified uses, but excessive intake can affect mineral balance, and environmental releases contribute to nutrient loading in water bodies. Proper handling and adherence to regulatory guidelines are advised.