Crystal salt lamp can give off natural negative ions, especially under the condition of heating, can effectively balance the positive and negative ions in the air, equivalent to an air purifier.

The German institute of biophysics has revealed the principle of air purification for salt lamps. The idea is that of sodium salt, a salt lamp that absorbs water from the air, then evaporates, then absorbs, then evaporates, over and over again, producing negative ions in the process. The heated salt lamp absorbs the water molecules in the surrounding air to the surface. When the salt is mixed with the water molecules, it will dissolve in the water after evaporation. Na+ and C1- return to the neutral state. This unique ion production process can only be found in the crystal salt mine, because the electroneutral atomic structure of the salt mine determines the salt mine's ability to produce negative ions in the presence of water.

According to expert statistics, the salt lamp can increase the mass of 500 to 700 negative ions for every cubic centimeter of air, especially suitable to be placed next to electrical appliances such as computer and TV to neutralize positive ions and shield the harmful radiation of electrical appliances.