Used as a reference standard in analytical laboratories for calibration and quantification of dyes in wastewater and industrial effluents. Commonly applied in spectrophotometric and chromatographic methods to detect and measure azo dye concentrations. Ensures accuracy and consistency in environmental monitoring, particularly in textile and dye manufacturing industries where Orange II levels must be controlled due to potential toxicity and environmental persistence. Also utilized in research studies on dye degradation, including evaluation of photocatalytic, biological, or chemical treatment efficiency.