Potassium hydroxide has very high alkalinity as measured on the pH scale. This scale goes from 0 to 14 and defines the acidity or alkalinity of a substance, with 7 being neutral, and alkaline being higher than 7. Pure distilled water has a pH of 7. Potassium hydroxide has a pH of 12 to 14. Compare this to ammonia at 10 to 11, and borax at 9.