Examples of oxidizers are chlorine, hydrogen peroxide, bromine, ozone, and chlorine dioxide.
Examples of reducers are sodium sulfite, sodium bisulfate and hydrogen sulfide.
Like acidity and alkalinity, the increase of one is at the expense of the other.
ORP is used for drinking water, swimming pools and spas. However, ORP is also used for cooling tower disinfection, groundwater remediation, bleaching, cyanide destruction, chrome reductions, metal etching, fruit and vegetable disinfection and dechlorination.
ORP is a convenient measure of the oxidizer’s or reducer’s ability to perform a chemical task. ORP is not only valid over a wide pH range, but it is also a rugged electrochemical test, which can easily be accomplished using in-line and handheld instrumentation. It is by far a more consistent and reliable measurement than say chlorine alone.