Used in environmental and industrial laboratories for calibration of analytical instruments to measure phenol levels in water, wastewater, and air samples. Ensures accurate detection of phenolic compounds in pollution monitoring and regulatory compliance testing. Commonly applied in quality control for pharmaceutical, chemical, and petrochemical industries where phenol is a raw material or byproduct. Also used in research settings for developing and validating analytical methods such as HPLC, GC, and spectrophotometry.