Sodium metaphosphate is a chemical compound with the formula NaPO3. It is a white, crystalline powder that is soluble in water. This compound is often used in various industrial applications, including as a food additive, where it acts as a preservative and emulsifier. In addition to its use in food, sodium metaphosphate is also utilized in detergents and cleaning products due to its ability to soften water. It can help improve the effectiveness of these products by enhancing their cleaning power.