Used as a pH indicator in analytical chemistry, changing color around pH 3.0 to 4.4, typically from red to yellow. Commonly employed in titrations involving strong acids and weak bases. Also utilized in some industrial processes as a dye for coloring solvents and polymers. Has been historically used in counterfeit alcohol testing due to color change in presence of certain impurities, though this application is limited today. Not suitable for food or biological use due to toxicity concerns.