What Is ORP? — Oxidation Reduction Potential Explained for Hydrogen Water

ORP (Oxidation Reduction Potential) is a measurement of a liquid's ability to act as an antioxidant or oxidant. Measured in millivolts (mV), a negative ORP value indicates antioxidant potential — the ability to donate electrons and neutralise free radicals. Kangen Water from the Enagic K8 machine typically measures between -300mV and -800mV.

What Does ORP Mean for Hydrogen Water?

• Negative ORP = antioxidant potential (electron donor)
• Positive ORP = oxidising potential (electron acceptor)
• Tap water: typically +200mV to +600mV (oxidising)
• Kangen Water K8: typically -300mV to -800mV (antioxidant)
• The lower the ORP, the greater the antioxidant potential

How Is ORP Measured?

ORP is measured using an ORP meter — a probe that measures the electrical potential of the water in millivolts. Fresh Kangen Water from the K8 machine shows the most negative ORP readings immediately after production.

ORP vs Molecular Hydrogen (H2)

ORP and molecular hydrogen concentration are related but distinct measurements. Molecular hydrogen (H2) is the active antioxidant molecule in hydrogen water. A high H2 concentration typically produces a strongly negative ORP. The K8 produces water with both high H2 concentration and strongly negative ORP.