Used as a reference standard in environmental testing to calibrate analytical instruments for detecting polychlorinated biphenyls (PCBs) in soil, water, and air samples. Commonly employed in gas chromatography and mass spectrometry to identify and quantify PCB contamination. Ensures accuracy and consistency in regulatory compliance testing, especially in industrial emissions and hazardous waste analysis. Also used in research studies focused on persistent organic pollutants and their impact on ecosystems and human health.