Ozone is a molecule consisting of three oxygen atoms. It is unstable and highly reactive. Ozone can be created during thunderstorms when lightning strikes the ground and ultraviolet radiation from the sun splits molecular oxygen (O2) into two individual oxygen atoms. These atoms then combine with other oxygen molecules to form ozone (O3).

Ozone has a high oxidation reduction potential, which means that it is capable of oxidizing other substances. This makes ozone an excellent disinfectant and bleaching agent. In fact, ozone more effective than chlorine at killing bacteria. It also eliminates odors and leaves behind no harmful residues.

Ozone Production Using Ozone Generator

Ozone is a powerful oxidant, meaning it can help to break down pollutants and other harmful chemicals. For this reason, ozone generators are often used to purify air and water. Ozone generators work by producing high levels of ozone, which can then be used to treat air or water. Ozone generators are used in a variety of settings, including homes, office buildings, and factories. When used properly, they can help to improve air quality and remove impurities from water.

What is ORP?

ORP is a term that may be heard frequently in the water treatment and food processing industries. ORP stands for Oxidation-Reduction Potential. So, exactly, what is it? ORP measures how clean the water is and how well it can break down pollutants. Because ozone is an oxidizing agent, we only care about positive ORP values (above 0 mV).

The dissolved oxygen is determined by ORP sensors. The lower the amount of organics in the water, the less available dissolved oxygen there is because they are consuming it. The greater the ORP level, the more effectively the water can destroy impurities like germs or carbon-based pollutants.

On the left side of this table, you’ll see ORP levels for several applications.

ORP Level (MV)Application
0-150No Practical Use
250-350Cooling Towers
400-475Swimming Pools
450-600Hot Tubs
600Water Disinfection 
800Water Sterilization 

How does an ORP Meter Work?

An ORP meter measures tiny voltages produced by a probe inserted into ozonated water. The electrode is composed of platinum or gold, which loses its electrons to the oxidizer and reversibly becomes recharged. A voltage is measured that is compared to a silver (reference) electrode in a silver salt solution, similar on the same principle as a pH probe. The greater the quantity of oxidizer available, the larger the voltage gap between the solutions.


The ORP level cannot be used to directly indicate dissolved ozone levels in water, unless the water is known to be very clean.


ORP is a chemical performance index that expresses how well an ozone solution can perform various tasks. ORP is accurate over a broad pH range, and in-line measuring ORP probes are sturdy enough to be placed into processes. The probes can withstand process pressures of more than 30 PSI.

ORP and Ozone


Using ORP in a clean water system to determine the dissolved ozone status is quite effective. Even small amounts of oxidizing power in moderate turbidity (cloudiness) systems may result in ORP readings that are far below predicted and even negative values. Monitoring ozone with ORP at the generator source generally works well, but measuring dirty water becomes unreliable at certain concentrations. Ozone detection kits are available and function effectively up to the limits permitted for various applications by EPA.

Bottom Line

The oxidation reduction potential of ozone is a measure of its ability to oxidize or reduce other molecules. This makes it an important tool for water treatment and purification, among other applications. Ozone has a very high oxidation reduction potential, making it an excellent choice for many industrial and commercial applications.