Oxidation-Reduction Potential (ORP) is a measure of the tendency of a solution to either gain or lose electrons and is commonly used to indicate the level of oxidation or reduction in water, measured in millivolts (mV). A positive oxidation-reduction potential value indicated that a solution is more oxidizing, while a negative oxidation-reduction potential value indicates that it is more reducing. This is often used an indicator of water quality, as high oxidation-reduction levels can indicate the presence of harmful oxidizing agents, such as chlorine or ozone, with some studies indicating damage to cells and tissue. Conversely, low oxidation-reduction potential levels can indicate the presence of reducing agents, which can therefore promote the growth of harmful bacteria and other microorganisms. Overall, it is important to maintain an appropriate oxidation-reduction potential level in water to ensure its safety and quality.