Complexometric indicators undergo discrete colour changes in the presence of specific metal ions. In analytical chemistry, they are used in titrations, showing an endpoint when all metal ions in the solution are sequestered by a chelating agent (most commonly EDTA).

Indicators are sold either in solution, or in the case of less stable indicators, as dry mixtures with inert salts. Both forms are ready for use in titration.

Eriochrome® is a registered trademark of Ciba-Geigy (now Novartis).

All products are produced locally in Canada by the Avalon Institute.