Chlorophenol red is an indicator dye that changes color from yellow to violet in the pH range 5.4 to 6.8.

[4] The dissociation mechanism of chlorophenol red is similar to that of phenolphthalein meaning it can be used as a color indicator.

[5] The pH properties of chlorophenol red are used to selectively determine the amount of chlorine dioxide in drinking water.

[6] The electrochemical properties of Chlorophenol red allows it to be a chromogenic label and can undergo oxidation creating several phenolic intermediates.

The bacterial hydrolysis of a chlorophenol red labelled substrate produces chlorine retaining intermediates on electrodes.