Redox refers to reduction-oxidation potential.It corresponds to the pressure of the balance between molecular hydrogen (H2) and molecular oxygen (O2). Oxidation refers to the loss or removal of electron(s) and/or the loss or removal of hydrogen atoms. Reduction refers to the gain or addition of electron(s) and/or the gain or addition of hydrogen atoms. It assess how strongly the fluid has a reducing potential. This is a measure of its anti-oxidant status.

If the reduction property (capable of suppressing oxidation) is strong, then it can suppress oxygen radicals, prevent metal rusting and prevent the oxidation of food. The lowering of redox potential plays a strong important role in health, beauty and wellness as well as disease prevention. The accelerated aging of cells is caused by oxygen radicals and hyper acid water. Yufuin water with its optimum Redox value can suppress these reactions.