Anything with a pH higher than 7 is alkaline; a pH below 7 is acidic. Water has a pH of 7; skin has an average pH of 5.5. Skin sensitization can be caused by products with a pH of 8 or higher. Also, research indicates that the bacteria on skin proliferates in alkaline environmental.References for this information:eMedicine Journal, January 7, 2002, volume 3, number 1Cutis, December 2001, Supplemental, pages 12Š—–19