Used as a reference standard in analytical laboratories for the quantification and detection of 4-phenylphenol in various samples. Commonly applied in environmental testing to monitor contamination in water and soil, especially from industrial sources. Also utilized in quality control during the production of biphenyl-based compounds, such as preservatives and antioxidants. Ensures accurate calibration of instruments like HPLC and GC-MS for reliable measurement in research and regulatory compliance.