The manufacturing process of soap, detergent and glycerin involves the use of salt. During this process, the soap is washed with concentrated brine solution (NaCl) to separate glycerin. This is done after the saponification reaction.

The solubility of soap in water increases with an increase in the size of monovalent cation. Similarly, an increase in divalent cation (Ca & Mg) results in a decrease in the solubility. The increase in the water solubility leads to the softness and mushiness of the soap. The divalent ions, Ca & Mg, cause problems during the manufacturing process of the soap by making it mushy and soft.