Proper pH balance is essential for your skin to perform its primary function as a barrier. Under normal conditions the surface of human skin is acidic with a pH 5. This low pH value is maintained in several different ways including through the production of free fatty acids during cell maturation and secretion of fatty acids and lactic acid in sweat. This acidic pH helps to protect the skin and to maintain the skins natural barrier function. Skintelligence pH Skin Normalizer assists your skin in maintaining a normal pH level and promotes your skins natural ability to resist the effects of pollution and other environmental conditions.