How Does SLSA Behave in Hard Water? SLSA (Sodium Lauryl Sulfoacetate) is a mild anionic surfactant widely used in shampoo bars, bath bombs, facial cleansers, and cleansing powders. When used in real-world conditions, one important factor that affects performance is water hardness. Hard water contains higher levels of minerals such as calcium (Ca²⁺) and magnesium (Mg²⁺), which can interact with …